Jejevo / Isabel B Environmental and Social Impact Assessment. Solomon Islands Nickel Project. Volume 3 Ecology

Transcription

1 Jejevo / Isabel B Environmental and Social Impact Assessment Solomon Islands Nickel Project Volume 3 Ecology March 2014

2 Jejevo / Isabel B Environmental and Social Impact Assessment Solomon Islands Nickel Project March 2014 Volume 1 Project and ESIA Overview Introduction Public Consultation Project Need and Alternatives Project Description Conceptual Mine Closure and Rehabilitation Plan ESIA Approach Environmental Management ESIA Summary Volume 2 Water Introduction Assessment Approach Mitigation Existing Conditions Linkage Analysis Impact Assessment Environmental Management and Monitoring Groundwater Baseline Report Freshwater Quantity Baseline Report Volume 3 Ecology Introduction Assessment Approach Mitigation Existing Conditions Linkage Analysis Impact Assessment Volume 4 Social Social Resources Impact Assessment Cultural Heritage Impact Assessment Human and Ecological Health Risk Assessment Transport Impact Assessment Visual Resources Impact Assessment Social Resources Baseline Report Cultural Heritage Baseline Report Volume 5 Physical Air Quality Impact Assessment Noise Impact Assessment Waste Management Air Quality Baseline Report Noise Baseline Report Waste Management Baseline Report Air Quality Modelling Report Freshwater Quality Baseline Report Marine Water and Sediment Quality Baseline Report Marine Hydrodynamics Baseline Report Climate Baseline Report Water Balance and Sediment Transport Model Report Erosion and Sediment Control Strategy Groundwater Impact Assessment Modelling Environmental Management and Monitoring Geology and Soils Baseline Report Terrestrial Ecology Baseline Report Marine Ecology Baseline Report Human and Ecological Health Baseline Report Transport Baseline Report Visual Resources Baseline Report Arsenic Food Study Baseline Report Air Risk Assessment Surface Water Risk Asessment Human and Ecological Health Toxicological Profiles for Metals

3 SMM Solomon Ltd. i Volume 3 TABLE OF CONTENTS SECTION PAGE 1.0 INTRODUCTION Study Objectives ASSESSMENT APPROACH Legislative Framework Solomon Islands Environment Act Other Solomon Islands Legislation International Conventions Japan Bank for International Cooperation International Finance Corporation International Council on Metals and Mining Other International Guidelines Assessment Methods General Overview Methods Impact Classification Management and Monitoring Spatial Considerations Geology and Soils Terrestrial Ecology Freshwater Ecology Marine Ecology Temporal Considerations Key Issues and Key Questions Geology and Soils Terrestrial Ecology

4 SMM Solomon Ltd. ii Volume Freshwater Ecology Marine Ecology Valued Components Geology and Soils Terrestrial Ecology Freshwater Ecology Marine Ecology Biological Indicators Geology and Soils Terrestrial Ecology Freshwater Ecology Marine Ecology MITIGATION Geology and Soils Terrestrial Ecology Freshwater Ecology Marine Ecology EXISTING CONDITIONS Geology and Soils Terrestrial Ecology Vegetation Communities and Flora Species Diversity and Richness Species Richness and Diversity Species of Concern Critical Habitat Freshwater Ecology Aquatic Habitat Macroinvertebrate Communities

5 SMM Solomon Ltd. iii Volume Fish Fauna Critical Habitat Assessment Marine Ecology Mangroves Species Seagrass Species Coral Species Deeper Low-profile Reef Coral Species Estuarine Fish Species Reef Fish Species Marine Mammal Species Marine Reptile Species Fisheries Resources LINKAGE ANALYSIS Geology and Soils Valid Linkages Invalid Linkages Terrestrial Ecology Valid Linkages Invalid Linkages Freshwater Ecology Valid Linkages Invalid Linkages Marine Ecology Valid Linkages Invalid Linkages IMPACT ASSESSMENT Geology and Soils

6 SMM Solomon Ltd. iv Volume What is the Effect of the Project on Soil Quantity? What is the Effect of the Project on Soil Quality? Terrestrial Ecology What is the Effect of the Project on Terrestrial Ecology? What is the Effect of the Project on Terrestrial Species of Concern? Freshwater Ecology What is the Effect of the Project on Freshwater Habitat? What is the Effect of the Project on Freshwater Valued Components? Marine Ecology What is the Effect of the Project on Marine Ecology? Prediction Confidence ENVIRONMENTAL MANAGEMENT AND MONITORING Geology and Soils Soil Quantity Soil Quality Terrestrial Ecology Land Clearance, Habitat Fragmentation and Edge Effects Direct Mortality Caused by Clearing Noise and Vibration Artificial Light Dust and Air Quality Introduction of Invasive Species, Feral Animals and or Exotic Species Increased Vegetation Gaps Causing Changes in Microclimates Freshwater Ecology Marine Ecology CONCLUSION Geology and Soils

7 SMM Solomon Ltd. v Volume Terrestrial Ecology Freshwater Ecology Marine Ecology REFERENCES GLOSSARY ABBREVIATIONS LIST OF TABLES Table 2.2-1: Ecology Impact Description Criteria Table 2.2-2: Sensitivity for Ecological Disciplines Table 2.2-3: Overall Impact Level for Ecological Disciplines Table 2.2-4: Overall Impact Level Matrix as a function of Sensitivity and Local Study Arealevel Effect Table 2.5-1: Ecology Key Questions Table 2.6-1: Terrestrial Ecology Valued Components Table 2.6-2: Freshwater Ecology Valued Components Table 2.6-3: Marine Ecology Valued Components Table 3.1-1: Geology and Soils Mitigation Measures Table 3.2-1: Terrestrial Ecology Mitigation Measures Table 3.3-1: Freshwater Ecology Mitigation Measures Table 3.4-1: Marine Ecology Mitigation Measures Table 5.1-1: Geology and Soils Linkage Analysis Table 5.2-1: Terrestrial Ecology Linkage Analysis Table 5.3-1: Freshwater Ecology Linkage Analysis Table 5.4-1: Marine Ecology Linkage Analysis Table 6.1-1: Residual Impact on Soil Quantity and Quality Table 6.2-1: Clearing Vegetation Types Table 6.2-2: Residual Impact on Terrestrial Ecology Table 6.2-3: Residual Effects on Terrestrial Species of Concern Table 6.3-1: Aquatic Habitat Loss Table 6.3-2: Residual Effects of Loss of Aquatic Habitat on Habitat Valued Components Table 6.3-3: Residual Effects of Sedimentation and Smothering of Benthic Habitat on Habitat Valued Components Table 6.3-4: Residual Effects of Loss of Aquatic Habitat on Biological and Cultural Valued Components Table 6.3-5: Residual Effects of Sedimentation and Smothering of Benthic Habitat on Biological and Cultural Valued Components Table 6.4-1: Residual Effects for Increased Turbidity and Sedimentation Table 6.4-2: Residual Effects for Direct Loss of Habitat Table 6.4-3: Residual Effects for Underwater Noise Table 6.4-4: Residual Effects for Light Table 6.4-5: Residual Effects for Introduced Marine Pests Table 6.4-6: Residual Effects for Accidental Spillage of Fuel during Refuelling Table 6.4-7: Residual Effects for Mobilised Metals from Mine Materials Table 6.4-8: Residual Effects for Collisions with Marine Fauna Table 6.4-9: Residual Effects for Increased Fishing Pressure Table : Residual Effects for Litter

8 SMM Solomon Ltd. vi Volume 3 LIST OF FIGURES Figure 2.3-1: Geology and Soils Local Study Area Figure 2.3-2: Terrestrial Ecology Study Areas Figure 2.3-3: Freshwater Ecology Study Areas Figure 2.3-4: Marine Ecology Study Areas Figure 5.1-1: Geology and Soils Linkage Diagram Figure 5.2-1: Terrestrial Ecology Linkage Diagram Figure 5.3-1: Freshwater Ecology Linkage Diagram Figure 5.4-1: Marine Ecology Linkage Diagram Figure 6.4-1: Estimates of Extent of Direct Habitat Loss LIST OF PHOTOGRAPHS Photograph 4.2-1: Flower of Tubi (Xanthostemon melanoxylon) Photograph 4.2-2: Solomon Islands Palm Frog (Palmatorappia solomonis) Photograph 4.2-3: Cockerell's Fantail (Rhipidura cockerelli) Photograph 4.3-1: A Potential New Species of Tateidae Snail (Gastropoda) LIST OF APPENDICES Appendix A: Geology and Soils Baseline Report Appendix B: Terrestrial Ecology Baseline Report Appendix C: Freshwater Ecology Baseline Report Appendix D: Marine Ecology Baseline Report

9 SMM Solomon Ltd. 1-1 Volume INTRODUCTION SMM Solomon Ltd. (SMM Solomon) is developing the Solomon Islands Nickel Project (SINP) on five tenements on two islands in Solomon Islands. The islands and tenements are: Choiseul Island (Choiseul tenement) Santa Isabel Island (Jejevo, Isabel B, D and E tenements) Environmental and Social Impact Assessments (ESIA) were completed and approved by the Solomon Islands government for the Choiseul, and Isabel D and E tenements in SMM Solomon is now submitting an ESIA and supporting documents for the Jejevo/Isabel B (the Project). The Project includes: mining area mine haul road ore stockpile jetty accommodation camp mine administration buildings transhipment mooring SMM Solomon will mine two ore types for the Project, limonite and saprolite. The limonite and saprolite will be mined and stockpiled separately, limonite will be transported to elsewhere and saprolite will be shipped to Japan for further processing. The Project will have a production of about Mt per year of ore and will operate for about 14 years. Volume 3 constitutes an impact assessment of the potential effects of the Project for each of the following disciplines (i.e., areas of study): Geology and Soils Terrestrial Ecology Freshwater Ecology Marine Ecology Baseline studies for each discipline are included as appendices to this volume (Appendix A to D). Together, these disciplines describe the baseline conditions and potential effects of the Project for the ecological components of the environment. The impact assessment describes effects of the Project on biodiversity, which is defined as the variety of life at different levels of biological organisation, and all the ecological and biological processes through which they are connected. That is, genetic diversity, species diversity and ecosystem diversity. Terrestrial ecology, freshwater ecology and marine ecology use, as the basis of their assessment of the Project s effects on biodiversity, the individual species level of organisation. Species can be defined as groups of morphologically similar organisms that have descended from a common ancestor, and which

10 SMM Solomon Ltd. 1-2 Volume 3 produce fertile offspring only amongst themselves. Species are the basic components of ecological communities and are the most recognisable units of biodiversity. Efforts to conserve biodiversity often focus at the species level. Effects to the higher, ecosystem level of biological organisation are also the subject of those sections. Ecosystems are a dynamic complex of plants, animals, micro-organisms, and their non-living environment interacting as a functional unit. Ecosystems can vary greatly in size, and in the biotic and abiotic elements of which they are comprised. However, ecosystems usually encompass specific, defined spaces. Ecosystems are distinct from communities in that the term community typically only refers to coexisting biotic populations, whereas ecosystems can include abiotic (i.e., non-living) components and an array of environmental processes. The Project s effects on ecosystem services, which are the benefits to people generated by a functioning natural environment, are not thoroughly assessed in this Volume. A preliminary assessment is provided in the social resources section (Volume 4, Section 1). It is recognised that a comprehensive assessment of the wider SINP s effects on ecosystem services is required, and that will be undertaken as a supplementary study to the ESIA. Not only is biodiversity important at all levels of biological organisation for generating ecosystem services, but so are many aspects of the physical environment, such as clean water (Volume 2), which are, in-turn, intrinsically linked to the social environment (Volume 4); after all ecosystem services do not exist without human beneficiaries. This approach has been adopted because it is recognised that the current Project is only a portion of a much larger SINP that sits in the wider Isabel and Choiseul area. Consequently, all the information that is required to undertake a thorough assessment of ecosystem services in the wider SINP area is not yet available, but will become available once all the ESIAs are complete. Similarly, effects to protected areas are not discussed in this ESIA, but will form part of a supplementary study for the SINP. Like ecosystem services, protected areas have strong linkages to both physical and social environments. Protected areas are often designated, at least in part, because of the high biodiversity values with which they are associated. However, it is recognised that no formally-recognised protected areas exist in the area of the Project. Nevertheless, an assessment of the community-designated protected areas will be undertaken for the SINP. Biodiversity value is a term used by the International Finance Corporation (IFC) in their Performance Standard 6 (PS6) on Biodiversity Conservation and Sustainable Management of Living Natural Resources (IFC 2012). Biodiversity values represent components of biodiversity at various levels of biological organisation, such as species or ecosystems that are important for conservation. Many of the unique and vulnerable biodiversity values associated with the Project require long-term comprehensive assessment; consequently, that assessment will form part of the proposed management and monitoring programme. 1.1 Study Objectives The objectives of the ecology impact assessment are to: Characterise the existing geological, chemical and physical properties of soils in the Project Area. Describe baseline ecology habitats and communities, including the relative distribution, abundance and general life history parameters. Identify species of concern (SoC), and provide the rationale and selection criteria used.

11 SMM Solomon Ltd. 1-3 Volume 3 Identify, at a preliminary level, potential critical habitat for species, based on baseline data. Describe the potential direct and indirect effects on ecology resulting from Projectrelated activities. Identify any necessary controls, mitigation and monitoring required for compliance with the identified performance criteria. Discuss design, construction and operational mitigation factors to be incorporated into the Project to minimise effects on ecology. Outline a management and monitoring program to assess Project-related effects on the ecology, and for measuring the effectiveness of mitigation.

12 SMM Solomon Ltd. 2-1 Volume ASSESSMENT APPROACH The overarching approach and methods used to identify and evaluate effects and impacts for each of the ecological disciplines is presented in Section 6, Volume 1, and should be read in conjunction with this volume. Each discipline section identifies key issues of concern, key questions, and valued components (VCs) using baseline information collected for the Project, in combination with international good practice guidelines and feedback from stakeholders and specialists. Effects were assessed for Project activities that are likely to result in a measureable environmental change that could contribute to adverse residual effects to VCs relative to baseline or guideline values. Complete lists of key questions and VCs are presented within each discipline section. After summarising baseline conditions, and identifying key issues, key questions and VCs, the objectives of each discipline-specific assessment are to: characterise interactions between Project activities and VCs to provide a comprehensive understanding of potential effects pathways from the Project for a given discipline identify mitigations applicable to the discipline that will be applied as part of the overall environmental design and management criteria for the Project, and describe any additional discipline-specific mitigations identified through the assessment evaluate project interactions in light of these mitigations using a linkage analysis (Section 5) and advance valid linkages with a potential to contribute to residual effects on discipline-specific VCs for assessment answer key questions by evaluating the effects of valid linkages on VCs describe prediction confidence and any uncertainty associated with the answers given to key questions identify any follow-up work or monitoring required as part of the management programme Each discipline assessment has been structured into sections reflecting these objectives. Within this general assessment structure, individual disciplines applied specific methods appropriate to their VCs. Broadly, however, geology and soils, terrestrial ecology, freshwater ecology, and marine ecology applied similar assessment methods, which are presented in this introductory section. 2.1 Legislative Framework Various legislative instruments, policies, guidelines, and international best practice governed and guided the assessment of Project effects on ecology. Provided below is a summary of those documents, as relevant to soils and geology, terrestrial ecology, freshwater ecology and marine ecology Solomon Islands Environment Act 1998 The Solomon Islands Environment Act 1998 (the Act) is the primary piece of legislation that regulates the protection and management of natural resources in Solomon Islands. The overall objective of the Act is to: provide for and establish integrated systems of development control, environmental impact assessment and pollution control

13 SMM Solomon Ltd. 2-2 Volume 3 prevent, control and monitor pollution reduce risks to human health and prevent the degradation of the environment by all practical means, including the following: regulate the discharge of pollutants to the air, water or land regulate the transport, collection, treatment, storage and disposal of wastes promote recycling, re-use and recovery of materials in an economically viable manner comply with and give effect to regional and international conventions and obligations relating to the environment The Act requires that any proposed development have regard as far as practicable to the effect such development would have on the environment, including completion of an Environmental Impact Assessment (EIA). The Act requires EIAs to: describe the environment likely to be affected by the prescribed development describe and assess any safeguards intended to be adopted for the protection of the environment state any intended monitoring and reporting of the effect of the prescribed development Other Solomon Islands Legislation Other Solomon Islands legislative mechanisms relevant to ecology include: National Environmental Management Strategy (NEMS 1993) Environmental Regulations 2008 Protected Areas Act (draft) 2012 Protection of Wrecks and War Relics Act 1973 Wildlife Protection and Management Act 1998 Provincial Government Act 1997 River Waters Act 1964 Fisheries Act 1998 and Subsequent Fisheries (Amendment) Act 2009 Environment Health Act 1980 National Biodiversity Strategy and Action Plan 2009 Isabel Province Conservation Area Ordinance 1993 Isabel Province Draft Resource Management and Environmental Protection Ordinance 2005 Isabel Province Marine and Freshwater Areas Ordinance 1993 Shipping Act 1998 Quarantine Act 1978 Marine Safety Administration Act 2009 Ports Act 1998

14 SMM Solomon Ltd. 2-3 Volume International Conventions Solomon Islands is a signatory to a number of international conventions and treaties. The following are relevant to ecology, and their implications were considered when assessing the effects of the Project: Convention on the Conservation of Cultural and Natural Heritage 1974 Convention on Conservation of Nature in the South Pacific (Apia Convention) 1976 Convention on the Conservation of Migratory Species of Wild Animals 1979 (the Bonn Convention) Convention for the Protection of the Natural Resources and Environment of the South Pacific Region, Noumea, 1986 United Nations Framework Convention on Climate Change, New York, 1992 Convention on Biological Diversity, Rio de Janeiro, Japan Bank for International Cooperation The Japan Bank for International Cooperation (JBIC) has guidelines regarding environmental and social considerations for projects it supports (JBIC 2012). The objective of the guidelines is to contribute to sound economic and social development with international projects that are subject to lending or other financial operations by JBIC. The JBIC will also determine whether a project meets its standard if it also meets the relevant aspects of the IFC PS, and other internationally-recognised standards and/or good international practices International Finance Corporation The IFC Performance Standards (PS) establishes standards that a proponent is to meet for their project throughout the life of an investment by the IFC. The Performance Standards establish the requirement to identify and evaluate risks and effects during a project, with establishment of baseline or ambient conditions being a necessary prerequisite. The Guidance Notes (IFC 2012a) are used to provide guidance with interpreting the Performance Standards with reference to a specific site or project. IFC Performance Standard 1 The objective of Performance Standard 1 Assessment and Management of Environmental and Social Risks and Impacts (IFC 2012b) is to identify and evaluate environmental and social risks and effects of the Project and adopt a mitigation hierarchy to anticipate and avoid, minimise or compensate/offset effects to workers, affected communities and the environment. There are requirements to identify environmental and social risks and effects in the context of the Project Area, and when unavoidable, identify mitigation and performance measures and establish corresponding actions to make sure the Project operates in compliance with applicable laws and regulations as well as meeting the requirements of PS 1 through 8. IFC Performance Standard 6 The objective of Performance Standard 6 Biodiversity Conservation and Sustainable Natural Resource Management of Living Natural Resources (IFC 2012c) is to protect and conserve biodiversity, maintain the benefits from ecosystem services, and promote the sustainable management of living natural resources through the adoption of practices that integrate conservation needs and development priorities.

15 SMM Solomon Ltd. 2-4 Volume 3 A requirement of PS6 is to assess species and habitat (i.e., modified, natural or critical habitat), consider direct and indirect project-related effects on biodiversity and ecosystem services, and identify any residual effects. When avoidance of effects is not possible, measures to minimise effects and restore biodiversity and ecosystem services should be implemented. Biodiversity offsets may be considered only after appropriate avoidance, minimisation and restoration measures have been applied. In summary, PS6 has specified requirements pertinent to the risks associated with biodiversity and sustainable development of living natural resources including (but not limited to): adaptive management planning design and implementation of biodiversity offsets minimise effects on modified habitats mitigation for conversions of natural habitat consistency with existing legal requirements, management plans and regulatory framework prevention of spread of alien species identify hierarchy of ecosystem services sustainable management to international standards International Council on Metals and Mining The International Council on Metals and Mining (ICMM) is a centre for performance improvement in the mining and metals industry. It has, at its core, 21 mining and metals companies, as well as 33 national and regional mining associations and global commodity associations to maximise the contribution of mining, minerals and metals to sustainable development. SMM Solomon is a member of ICMM. The ICMM s publishes good practice guidance for the mining and metals industry. relevant to ecology, the following guidance was considered: As Mining and Biodiversity Good Practice Guidance The Cross Sector Biodiversity Initiative (CSBI) tool. The CSBI is a partnership between ICMM, IPIECA (the global oil and gas industry association for environmental and social issues) and the Equator Principles Association. The initiative aims to develop and share good practices for the effective application of the IFC PS Other International Guidelines An Overview of the Abundance, Relative Mobility, Bioavailability, and Human Toxicity of Metals (Smith and Huyck 1999). This guideline was used to determine the average crustal abundance values for soil. These values can give an indication of how metal and metalloid concentrations in the Project Area compare to average crustal concentrations in other regions of the world. The Global Acid Rock Drainage Guide 1999 (GARD Guide). Results of soil analysis were compared against this guide from the International Network for Acid Prevention. It provides methods for assessing any elemental enrichment of soils that may be of environmental importance. State Planning Policy 2/02: Guideline for Planning and Managing Development involving Acid Sulfate Soils (SPP2/02) (Queensland Government 2002). Acid sulfate

16 SMM Solomon Ltd. 2-5 Volume 3 soils (ASS) were assessed under this guidance. It provides guidance on the assessment and management of developments in environments affected by ASS. 2.2 Assessment Methods General Overview As mentioned, the methods presented in this section are common amongst disciplines addressing soils and geology, and biodiversity at the species and ecosystem levels of biological organisation. The objective of the impact assessment for ecology disciplines is to meet the targets of the IFC Performance Standard 6 (PS6) (IFC 2012). The ecology assessment, therefore, concentrates on assessing changes in geology and soils, habitat, changes in populations of SoC, including invasive species and species of high value to people, and changes to ecosystem function. As part of its focus on the protection and conservation of biodiversity, IFC PS6 uses the concept of critical habitat (CH) as an important means to identify biodiversity values of key conservation concern. Critical habitat constitutes areas of a particularly sensitive nature for biodiversity conservation that deserve special attention and may require extraordinary mitigations. Identifying critical habitat is important for understanding key environmental risks associated with a project. Biodiversity values potentially triggering CH were an important component of the VCs selected by each ecology discipline. The IFC PS6, and the associated guidance notes (GN6) (IFC 2012), set criteria for proponents proposing projects in CH. Specifically, GN6 requires that a project does not lead to irreversible adverse impacts to the biodiversity value for which CH was designated, or to net declines in a critically endangered (CR) or endangered (EN) species over a reasonable period of time. Both a footnote to PS6 (page 14) and the guidance notes (GN6 104) indicate that what constitutes a reasonable period of time should be determined on a case by case basis through consultation with external experts. The IFC PS 6 further notes that, if the requirements of the above criteria cannot be met, a Biodiversity Action Plan (BAP) will be developed to achieve net gains of those biodiversity values for which the CH was designated. The GN6 (GN 107) expands on the options to achieve net gain, especially through offsetting. A preliminary assessment of CH for identified VCs is presented as part of each discipline (except soils and geology). A more rigorous and through assessment of CH will be undertaken for the wider SINP, which will focus on the IFC s concept of discrete management units (DMU). It was deemed that conducting two, rigorous CH assessments would be superfluous because the same area, and hence CH, is being dealt with across the whole SINP area, that is, the wider Jejevo/Isabel B Tenements, and the Isabel D and E tenements of the SINP. The same CH will overlap all these areas. Therefore, it was thought more appropriate to have a single, comprehensive CH assessment for the four tenements, rather than separate assessments. That CH assessment will be a supplement to this ESIA. A BAP will be developed for the Project (Section 7). The BAP provides a strategic overview of the Project s biodiversity management strategy and commitments. A management plan will be developed to implement the mitigation commitments detailed in the BAP. Key questions for the biodiversity disciplines were answered using a two-step process. First, an overall written analysis, identifying methods used for the assessment, the logic of the assessment and the conclusions reached. Second, a formal impact classification is applied that meets the specific requirements of the ecology assessments Methods The following sections describe:

17 SMM Solomon Ltd. 2-6 Volume 3 the study areas, which set the spatial boundaries of the assessment the assessment timeframe, which identifies the bounding cases and snapshots used for assessing effects to ecology the methods used for impact classification Analysis The analysis section for each key question first presents the methods used to estimate a change in condition for each VC. Changes in condition were defined as changes to the size or function of a population, habitat, or ecosystem from baseline condition. Methods to estimate change in condition included models, calculations, and qualitative analyses based on available information from baseline reports, scientific literature, and expert consultation. Methods were described in sufficient detail to allow for repeatability. Methods used in the analysis section were specific to groups of VCs, or individual VCs, and are presented in the various discipline sections, as appropriate. After presenting the methods, the analysis was structured using indicators. Indicators are quantifiable (i.e., measurable) expressions of changes to a VC that are used to answer key questions. The indicators selected for a particular discipline or VC were those that helped to understand whether the fundamental properties of a VC that should be conserved, such as self-sustaining and ecologically-effective populations of plants and animals, would be meaningfully affected by the Project. An example of an indicator used by all disciplines in this assessment (except soils and geology) is the change in quality or quantity of habitat due to the Project. For each key question and VC, indicators were addressed in order from lowest to highest contribution to an adverse effect to a VC. As noted in the assessment timeframe (Section 2.4), indicators were evaluated and described for the maximum disturbance snapshot. For each indicator, the effect attributes described in Section were used to guide the assessment. These include direction, magnitude, geographic extent, duration, frequency and reversibility. Where possible, magnitude was quantified as a specific value, such as change in population size or number of hectares of habitat lost. These criteria were considered together to determine the overall effect of the Project on a VC, and the effects are described using a reasoned narrative Impact Classification A formal impact classification was completed using the results described in the analysis. The purpose of the impact classification was to provide a system for ranking the level of effects in a clear and repeatable way that permits comparison among ecology VCs, and categorises the overall impact level for each VC in light of the mitigation applied, as well as IFC PS6 requirements. The impact classification for the ecology disciplines follows the general principles described in Volume 1, Section 6. The first step in the impact classification was to determine the effect of the Project in the Local Study Area (LSA). The effect was quantified by combining the rankings for direction, geographic extent, duration, frequency, reversibility and magnitude into a single measure. To classify magnitude using an ordinal scale (i.e., negligible, low, moderate, or high) in a manner meaningful for ecology VCs, the size of the effect must be placed in the context of the VC. That is, classifying magnitude in a meaningful way depends on the historical and ecological context of the VC, which includes effects of previous and existing developments and population trajectories of the VC in the LSA, and will be VC-specific. For example, 20% additional habitat loss from the baseline condition in the LSA may be required to cause a high magnitude effect on some VCs, whereas a 2% habitat loss may be sufficient for others, depending on context. Fixed quantitative thresholds to define ordinal magnitude categories

18 SMM Solomon Ltd. 2-7 Volume 3 were therefore not applied. Instead, qualitative descriptions of the potential for an effect of a given size to contribute to a substantial change in the structural integrity (e.g., self-sustaining population) or ecological function were used (Table 2.2-1). Magnitude was then combined with duration, geographic extent, frequency and reversibility using the reasoned narrative presented in the analysis section to define an overall LSA-level effect. Defining quantitative ecological benchmarks to bound regional effect-level categories for ecology is challenging, and each species, ecosystem, and situation requires specific analysis (Fahrig 2003, Groffman et al. 2006; Petchey and Gaston 2006). Ideally, effect-threshold values are known, and indicators can be quantified accurately with a high degree of confidence; but, critical thresholds and target levels for indicators such as habitat quality, quantity, and configuration (e.g., patch size, number and isolation) are frequently not available for biodiversity. Moreover, thresholds vary by species, landscape type, and spatial scale (Fahrig 2001), and unexpected outcomes occur (e.g., some species that avoid human features in relatively undisturbed landscapes can change their behaviour to accommodate disturbance where it is more prevalent) (Martin and Blackburn 2010). Effect classification was based on the inferred or known ability of the VC to accommodate the predicted change in condition due to the Project; this was based on available scientific literature and consultation with experts. Where ecologically-defensible, VC-specific thresholds could be identified, they were applied to indicators to classify effect. Definitions of the different levels of project effect at the LSA scale are presented in Table Effect classes relate to the level of change compared to natural variation, plus the ecology components ability to absorb or otherwise accommodate the predicted amount of change.

19 SMM Solomon Ltd. 2-8 Volume 3 Table 2.2-1: Ecology Impact Description Criteria Environmental Component Geology and Soils Terrestrial Ecology Direction Negative: Effect on valued component is worsening compared with baseline conditions and trends Neutral: Effect on valued component is not changing compared with baseline conditions and trends Positive: Effect on valued component is improving compared with baseline conditions and trends Negative: Effect on valued component is worsening compared with baseline conditions and trends Neutral: Effect on valued component is not changing compared with baseline conditions and trends Positive: Effect on valued component is improving compared with baseline conditions and trends Magnitude No effect: Effect does not occur - negligible: no measurable effect to <1% Low: Effect occurs that might or might not be detectable but is within the normal range of variability, 1 to <10% change in measurement indicator Moderate: Effect occurs but unlikely to pose a serious risk to the valued component, 10 to 20% change in measurement indicator High: Effect is likely to pose a serious risk to the valued component, >20% change in measurement indicator No effect: Effect does not occur - negligible: no measurable effect to <1% Low: Effect occurs that might or might not be detectable but is within the normal range of variability, 1 to <10% change in measurement indicator Moderate: Effect occurs but unlikely to pose a serious risk to the valued component, 10 to 20% change in measurement indicator High: Effect is likely to pose a serious risk to the valued component, >20% change in measurement indicator Geographical Extent Local: Effect on valued component in LSA Regional: Effect on valued component in RSA Beyond regional: Effect on valued component extends beyond the RSA Local: Effect on valued component in LSA Regional: Effect on valued component in RSA Beyond regional: Effect on valued component extends beyond the RSA Duration Frequency Reversibility Short term: Effect on valued component is limited to less than one year Medium term: Effect on valued component lasts from one to 14 years Long term: Effect on valued component lasts 14 to 30 years Far Future: Effect on valued component continues for more than 30 years Short term: Effect on valued component is limited to less than one year Medium term: Effect on valued component lasts from one to 14 years Long term: Effect on valued component lasts 14 to 30 years Far Future: Effect on valued component continues for more than 30 years Negligible: Effects occurs only once Low: Effects occurs intermittently and less than once per day Moderate: Effects occurs intermittently but more than once per day High: Effects occurs continuously Negligible: Effects occurs only once Low: Effects occurs intermittently and less than once per day Moderate: Effects occurs intermittently but more than once per day High: Effects occurs continuously Reversible Irreversible Reversible Irreversible

20 SMM Solomon Ltd. 2-9 Volume 3 Table 2.2-1: Ecology Impact Description Criteria (continued) Environmental Component Direction Magnitude Freshwater Ecology Negative: Effect on valued No effect: Effect does not occur - component is worsening negligible: no measurable effect compared with baseline to <1% conditions and trends Marine Ecology Neutral: Effect on valued component is not changing compared with baseline conditions and trends Positive: Effect on valued component is improving compared with baseline conditions and trends Negative: Effect on valued component is worsening compared with baseline conditions and trends Neutral: Effect on valued component is not changing compared with baseline conditions and trends Positive: Effect on valued component is improving compared with baseline conditions and trends Low: Effect occurs that might or might not be detectable but is within the normal range of variability, 1 to <10% change in measurement indicator Moderate: Effect occurs but unlikely to pose a serious risk to the valued component, 10 to 20% change in measurement indicator High: Effect is likely to pose a serious risk to the valued component, >20% change in measurement indicator Negligible: no detectable effect on habitat or species or aquatic resource (i.e., a change, if it occurs, is within the normal range of variability) Low: effect may be detectable but is small and unlikely to have any material impact to population, ecosystem or community survival or health. Moderate: effect will be detectable but not severe (i.e., reduction in population or the areal extent of communities but this will not lead to major changes to population, ecosystem or community survival or health) High: effect likely to be a severe impact on population, ecosystem or community survival or health, possibly resulting in local extinction or system collapse. Geographical Extent Local: Effect on valued component in LSA Regional: Effect on valued component in RSA Beyond regional: Effect on valued component extends beyond the RSA Site: effect is localised (less than 1 km) Local: affecting populations in the local area (up to 4 km from/along the coast or the area of Project activity) Regional: effect is widespread, the extent of which is greater than local but within the area of the RSA. Beyond regional: effects extends beyond the RSA Duration Frequency Reversibility Short term: Effect on valued component is limited to less than one year Medium term: Effect on valued component lasts from one to 14 years Long term: Effect on valued component lasts 14 to 30 years Far Future: Effect on valued component continues for more than 30 years Short term: effect is not detectable within two years after the disturbance Medium term: effect is detectable for longer than two years, but less than ten years after the disturbance Long term: effect is detectable for longer than ten years, but less than 25 years after the disturbance Far Future: effect extends for 25 years or longer Negligible: Effects occurs only once Low: Effects occurs intermittently and less than once per day Moderate: Effects occurs intermittently but more than once per day High: Effects occurs continuously Negligible: Effects occurs only once Low: Effects occurs intermittently and less than once per day Moderate: Effects occurs intermittently but more than once per day High: Effects occurs continuously Reversible Irreversible Reversible Irreversible

21 SMM Solomon Ltd Volume 3 An overall impact level, reflecting the expected conservation outcome of the Project in a global context, was assessed using the predicted effect level to the VC within the LSA, combined with the global sensitivity of the VC. Sensitivity represents the global conservation status of a VC, and was quantified primarily using the CH-determining criteria of IFC PS6 (2012). As such, sensitivity is based on scientific principles of biodiversity conservation and did not include human values regarding VCs. Sensitivity for each VC ranged from low to very high according to increasing level of global threat (Table 2.2-2). Sensitivity was combined with LSA-level effect to obtain an overall impact level (Table 2.2-3) using the matrix presented in Table Overall impact levels were classified for the maximum disturbance case. Table 2.2-2: Sensitivity for Ecological Disciplines Attribute Low Medium High Definition A species that is listed as of least concern or is not listed under the IUCN, and is common and/or has no recognition in Solomon Islands. An environmental value that is of little or no reported local importance. An environmental value of occasional subsistence, artisanal or commercial use. A regional endemic; species or ecosystem distribution reduced from former extent and/or ecosystem distribution fragmented and/or under stress. A species that is listed as vulnerable, near threatened or data deficient under the IUCN, and/or recognised as such in Solomon Islands. An environmental value of regional or local importance. An environmental value of common subsistence, artisanal or commercial use or habitat of importance in maintaining ecological integrity IUCN status of critically endangered (CR), or endangered (EN); locally endemic or range is restricted to the Regional Study Area/critical habitat area of analysis; local temporal concentrations of individuals important to global population; much reduced and/or highly fragmented species and/or/ecosystem distribution compared to former extent; ecosystem representation whose presence or processes support critically endangered or endangered species' habitat, or buffers it; keystone species; and/or species new to science Table 2.2-3: Overall Impact Level for Ecological Disciplines Attribute Definition Negligible Low Moderate High Very high No negative impacts to VCs from the Project. Impact level minimal to viability or integrity of valued components; mitigation is adequate and achievable and monitoring may be necessary Impact level requires follow up action, including the possibility of offsetting; monitoring necessary to evaluate continued viability or integrity of valued components and provide opportunities for adaptive management. Impact level requires careful, specific, higher-level mitigation and/or compensation design (i.e., offsetting); implies proximity to, and uncertain risk of exceedance of, project management thresholds; monitoring necessary to evaluate continued viability or integrity of VCs and provide opportunities for adaptive management. Impact level is unacceptable; resilience of VC stressed to the extent that recovery is not considered possible; exceedance of legal standards and widely accepted good practice.

22 SMM Solomon Ltd Volume 3 Table 2.2-4: Overall Impact Level Matrix as a function of Sensitivity and Local Study Area-level Effect Impact Level Sensitivity of Receptor High Medium Low High Extreme Major Moderate Moderate Major Moderate Minor Low Moderate Minor Negligible Negligible Negligible Negligible Negligible Positive Positive Positive Positive As noted above, overall impact level was calculated separately for the maximum disturbance case. For example, a moderate Project effect to a very high-ranked sensitive VC would result in a moderate overall impact level. That determination of a moderate overall impact would lead to additional mitigation and management measures being devised, over-andabove those already proposed. This would include a more intensive monitoring program to make sure the effects do not increase. On the other extreme, a low Project effect to a high-ranked sensitive VC would result in a very high overall impact level. Very high overall impact level means that, with current baseline understanding and current Project design, the proposed mitigation and management measures, with respect to IFC PS 6, are predicted to be exceeded. Such a situation would necessitate one or more of: a Project design change; additional mitigation; or additional understanding of baseline conditions that would lead to a predicted lower consequence Prediction Confidence Identified effects were discussed in light of confidence in effects predictions based on data quality, model accuracy and any uncertainty about ecological processes or efficacy of mitigation. Management and Monitoring Additional actions and/or follow-up monitoring were proposed in cases where uncertainty was high or where the consequences of an inaccurate prediction could lead to unacceptable outcomes according to the Project proposed mitigation measures. Additional actions included: research to improve confidence in effect size predictions, such as searching for additional confirmed populations of plants and animals outside of the Project footprint. Monitoring was proposed as a means to adaptively manage ecological values by identifying changes over time and providing opportunities for iterative mitigation during the Project lifecycle. 2.3 Spatial Considerations Described in the following sections are the spatial boundaries used for the assessment of Project effects on geology and soils, terrestrial ecology, freshwater ecology, and marine ecology. The LSAs for geology and soils, terrestrial ecology, freshwater ecology, and marine ecology were used to focus the studies to where potential direct project effects were predicted to occur (Figure 2.3-1, Figure 2.3-2, Figure and Figure 2.3-4). The LSA boundaries enclosed the Project footprint, plus a buffer to include non-footprint direct effects, including those resulting from changes to water flow and quality, air quality and noise. Baseline studies sometimes extended beyond the LSA into a Regional Study Area (RSA) to provide a regional context for the information collected in an LSA.

23 515, , , ,000 SOLOMON ISLANDS NICKEL PROJECT 9,105,000 JEJE VO JS05 JS08 JS12 9,105,000 SMM SOLOMON LTD GEOLOGY AND SOILS LOCAL STUDY AREA JS04 JS07 JS09 JS10 JS11 SIVOKO JS26 Buala Information contained on this drawing is the copyright of Golder Associates Pty. Ltd. Unauthorised use or reproduction of this plan either wholly or in part without written permission infringes copyright. Golder Associates Pty. Ltd. 9,100,000 9,095,000 9,090,000 ELEVATION 750m 0 Project Footprint Transhipment Mooring Linear Infrastructure Defined Resource Area Accommodation Camp Jetty Potential Resource Area Stockpile 515,000 OLA Other Surface Infrastructure Weir Storage HUGHUKAPOTE Nuha Camp JS32 SIVOKO JS36 Dadale Logging Camp 520,000 JS35 NUHA JS42 JS43 Pauo Point JIHRO KO LOSIGHONI Kolosighone Poloasi Hurepelo 525,000 HEPLE Tamaro Nasinagao JS24 Jajao Logging Camp Jajao Village 530,000 GAJUHON GARI Madagha Upper Gora Jajao Base 1 Gugugluro Madagha M ADAGHA GORA 9,100,000 9,095,000 9,090,000 LEGEND NOTES Sample Location Camp Village Logging Road Trail Watercourse Named Watercourse Unnamed Waterbody Jejevo Tenement Isabel B Tenement SSR Boundary Local Study Area ,400 2,100 2,800 3,500 Metres SCALE (at A3) 1:70,000 DATUM WGS 84, PROJECTION UTM Zone 57 South PROJECT: DATE: DRAWN: CHECKED: REVIEWED: Kolomola 1. Tenement boundaries supplied by Client. 2. Base data copyright Solomon Islands Government, Ministry of Land. 3. Key Inset Bathymetry copyright National Oceanic and Atmospheric Administration (NOAA), Key Inset Terrain copyright Consultative Group on International Agricultural Research (CGIAR), F-Rev FEB 2014 MC EB IGG FIGURE File Location: R:\01 Client\Sumitomo\ \Programs\ArcMap\Ecology\Geology and Soils\Rev0\ F-Rev Local Study Area (Impact Assessment).mxd

24 515, , , ,000 SOLOMON ISLANDS NICKEL PROJECT SMM SOLOMON LTD U ID S 9,105,000 Buala Kolomola LEGEND Camp Village Logging Road SIV O Trail Watercourse Named Watercourse Unnamed KO Waterbody Jejevo Tenement E T PO KA HU GH U Isabel B Tenement SSR Boundary Freshwater Swamp / Lowland Forest Lowland Forest Mangrove A OL Local Study Area Regional Study Area SIVOKO N A UH 9,100,000 Nuha Camp 9,100,000 Information contained on this drawing is the copyright of Golder Associates Pty. Ltd. Unauthorised use or reproduction of this plan either wholly or in part without written permission infringes copyright. Golder Associates Pty. Ltd. 9,105,000 TERRESTRIAL ECOLOGY STUDY AREAS NOTES J IHRO 1. Tenement boundaries and helipads supplied by Client. 2. Base data copyright Solomon Islands Government, Ministry of Land. 3. Key Inset Bathymetry copyright National Oceanic and Atmospheric Administration (NOAA), Key Inset Terrain copyright Consultative Group on International Agricultural Research (CGIAR), ELEVATION 750m KO L 0 I IGHON OS PROJECT: DATE: DRAWN: CHECKED: REVIEWED: Dadale Logging Camp Jetty Potential Resource Area Stockpile HEPLE Other Surface Infrastructure Weir Storage 515, ,000 Pauo Point 525, ,000 File Location: R:\01 Client\Sumitomo\ \Programs\ArcMap\Ecology\Terrestrial Ecology\Rev0\ F-Rev Terrestrial Ecology Study Areas.mxd Kolosighoni 1,000 1,500 1:50,000 2,000 2,500 Metres DATUM WGS 84, PROJECTION UTM Zone 57 South Project Footprint Linear Infrastructure Accommodation Camp 500 SCALE (at A3) 0 Defined Resource Area 250 Tamaro F-Rev FEB 2014 SL DJ IGG FIGURE 2.3-2

25 I 510, , , , , ,000 SOLOMON ISLANDS NICKEL PROJECT HUHURANGI SMM SOLOMON LTD 9,110,000 Z ENGIRO SIDU 9,110,000 FRESHWATER ECOLOGY STUDY AREAS Jejevo (west) Molforu JE JE VO Jejevo (east) Buala Kolomola Information contained on this drawing is the copyright of Golder Associates Pty. Ltd. Unauthorised use or reproduction of this plan either wholly or in part without written permission infringes copyright. Golder Associates Pty. Ltd. 9,090,000 9,095,000 9,100,000 9,105,000 ELEVATION 750m 0 Project Footprint Transhipment Mooring Linear Infrastructure Defined Resource Area Accommodation Camp Jetty Potential Resource Area Stockpile 510,000 Furona Other Surface Infrastructure Weir Storage Jejevo 515,000 OLA HUGHUKAPOTE Nuha Camp SIVOKO SIVOKO Dadale Logging Camp 520,000 NUHA Pauo Point JIHRO Kolosighone KOLOSIG H ONI Poloasi Hurepelo 525,000 HEPLE Tamaro Nasinagao Jajao Logging Camp Jajao Village Madagha Upper 530,000 G AJUHO NGAR Gora Gugugluro Jajao Base 1 M ADAGHA Madagha GORA NANARENI 535,000 9,105,000 9,100,000 9,095,000 9,090,000 LEGEND Camp NOTES Village Watercourse Named Watercourse Unnamed Waterbody Jejevo Tenement Isabel B Tenement SSR Boundary Catchment Boundary Local Study Area Regional Study Area 1. Tenement boundaries supplied by Client. 2. Base data copyright Solomon Islands Government, Ministry of Land. 3. Key Inset Bathymetry copyright National Oceanic and Atmospheric Administration (NOAA), Key Inset Terrain copyright Consultative Group on International Agricultural Research (CGIAR), km SCALE (at A3) 1:90,000 DATUM WGS 84, PROJECTION UTM Zone 57 South PROJECT: DATE: DRAWN: CHECKED: REVIEWED: F-Rev FEB 2014 MC NC IGG FIGURE File Location: R:\01 Client\Sumitomo\ \Programs\ArcMap\Ecology\Freshwater Ecology\Rev0\ F-Rev Freshwater Ecology Local Study Area and Regional Study Area (Impact Assessment).mxd

26 Migi 500,000 NAHAO 510, , ,000 HU H URAN G I SOLOMON ISLANDS NICKEL PROJECT SMM SOLOMON LTD 9,110,000 Korighole ZENG IRO SIDU 9,110,000 MARINE ECOLOGY STUDY AREAS Kopakana Camp Molforu JE JE VO Information contained on this drawing is the copyright of Golder Associates Pty. Ltd. Unauthorised use or reproduction of this plan either wholly or in part without written permission infringes copyright. Golder Associates Pty. Ltd. 9,100,000 9,090,000 9,080,000 ELEVATION 750m 0 Project Footprint Transhipment Mooring Linear Infrastructure Defined Resource Area Accommodation Camp Jetty Potential Resource Area Stockpile Other Surface Infrastructure Weir Storage 500,000 Furona 510,000 Jejevo OLA HUGHUKAPOTE Nuha Camp Dadale Logging Camp SIVOKO SIVOKO 520,000 NUHA Pauo Point JIHRO Kolosighone Poloasi Hurepelo KOLOSIGHONI HEPLE Tamaro Nasinagao Jajao Village Madagha Madagha Upper 530,000 GAJUH ONGARI Jajao Logging Camp Jajao Base 1 Gora Khomuro Gugugluro Kilokaka Galili KUMA'IBUSI 9,100,000 9,090,000 9,080,000 LEGEND Camp NOTES Village Logging Road Trail Watercourse Named Watercourse Unnamed Waterbody Jejevo Tenement Isabel B Tenement SSR Boundary Local Study Area Regional Study Area ,500 3,000 4,500 6,000 7,500 Metres SCALE (at A3) 1:150,000 Buala Kolomola 1. Tenement boundaries supplied by Client. 2. Base data copyright Solomon Islands Government, Ministry of Land. 3. Key Inset Bathymetry copyright National Oceanic and Atmospheric Administration (NOAA), Key Inset Terrain copyright Consultative Group on International Agricultural Research (CGIAR), DATUM WGS 84, PROJECTION UTM Zone 57 South PROJECT: DATE: DRAWN: CHECKED: REVIEWED: F-Rev FEB 2014 TWB EL IGG FIGURE File Location: R:\01 Client\Sumitomo\ \Programs\ArcMap\Ecology\Marine Ecology\Rev0\ F-Rev Marine Ecology Study Areas.mxd

27 SMM Solomon Ltd Volume Geology and Soils The LSA was established to assess the contributions and effects of the Project on soils. The LSA for the Geology and Soils component of the Project is presented in Figure The LSA is defined based on the following criteria: area is in the Special Site Right (SSR) and tenement boundaries area is intended for mining activities area is intended for infrastructure (e.g., ports, camp) area may be a potential acid sulfate soil (ASS) environment The RSA for the Geology and Soils component is considered to be Santa Isabel Island Terrestrial Ecology The LSA, RSA, and Project Area were defined for the terrestrial ecology. The Project Area includes land that is subject to direct disturbance from the Project and associated infrastructure. The LSA includes the local surrounding area and, for the purpose of this assessment, has been delineated by the Hughukapote River to the west, through to the Heple River in the east. The northern LSA boundary is defined by the central ridge line to the north of the Jejevo tenement. This main ridgeline slopes steeply to river valleys both north and south. Watercourses dissect the ridgeline through the centre. Further east, the landscape is less steep, characterised by open valleys with extensive deposits of quaternary colluvium and alluvium. For the purposes of this assessment, the RSA extends from the mountain range directly to the north of the LSA, as far as Jejevo village to the west, and Jajao to the south (approximately 200 km 2 ). This area was deemed appropriate given the potential for indirect effects from the Project on the ecology in these areas surrounding the Project. The LSA, RSA and Project Area are shown in Figure Freshwater Ecology As with terrestrial ecology, a LSA, RSA, and Project Area were defined for freshwater ecology. The Project Area was effectively the same as that delineated for terrestrial ecology, and included land that is subject to direct disturbance from the Project and its infrastructure. The LSA included the catchments of: Jejevo River (east catchment) Nuha River Sivoko River Hughukapote River The RSA included the catchments of: Heple River Ola River

28 SMM Solomon Ltd Volume 3 Jejevo River (west catchment) The LSA, RSA and Project Area are shown in Figure Marine Ecology The marine ecology LSA was defined based on the: area of coastline that may be directly affected by the Project (e.g., near-shore jetty facilities and trans-shipment mooring facility) coastal downstream receiving environment of rivers (i.e., Jejevo, Hughukapote, Sivoko, Nuha and Heple Rivers) potentially affected by the Project The LSA extends from the area immediately west of Jejevo River, to the area immediately east of Heple River, and includes about 20 km of coastline. The LSA also extends about 2.5 km to 6 km offshore to include the barrier reefs, and 1 km inland to include Sivoko Lake, The extent of the LSA includes the dominant coastal fringing habitats, as well as coral reefs in the lagoon areas and those further offshore on the barrier reefs. The RSA is considered to be the shoreline and marine areas up to 10 km from the LSA boundary (both along the coast and offshore, but not inland). The LSA and RSA are shown in Figure Temporal Considerations The life of the Project is approximately 10 years of ore extraction with a 1 year construction period, and 3 year decommissioning and rehabilitation period. The assessment of effects for all the ecological disciplines considered all activities associated with the Project over its life, including construction, operation, decommissioning and closure. The Project will begin affecting ecology once construction starts, and will continue to affect it at least until active, progressive reclamation and rehabilitation is complete, 14 years later. For some ecology and biodiversity values, Project effects may continue until vegetative succession is complete in the Far Future (i.e., 50 years post closure), or may be permanent. Two assessment cases are assessed: The Baseline Case describes the conditions that exist if the Project were not developed and includes the effects resulting from existing and approved projects or activities in the study areas. The Application Case includes the Baseline case with potential effects associated with the Project included. The Application Case addresses and answers the ecology key questions for the Project. For ecology, the Baseline Case is defined as the condition of the environment in This was the year during which vegetation and disturbance in the LSA, and parts of the RSA was mapped, and when most of the detailed baseline surveys were completed. Baseline conditions for the various ecology disciplines are presented in Appendices A to D. For the Application Case, the ecology discipline assessments describe changes from baseline conditions predicted as a result of the Project. Project effects upon ecology are sometimes specific to a particular development phase (i.e., construction, operation, decommissioning and closure), and may change over time as the Project advances through

29 SMM Solomon Ltd Volume 3 the various phases (Section 2.4). These kinds of temporal variations, in effect, were considered in the ecology assessments and were described qualitatively for each VC as appropriate. The assessment was done in consideration that the entire Project footprint would be cleared for the life of the Project (i.e., 14 years). This is a conservative approach to the assessment because the entire Project footprint will not be cleared in its entirety at any time in the Project life. The mine area will be progressively rehabilitated as areas are mined out. It is estimated that no more than 0.42 ha of the mine area will be cleared at any time. In addition to the Baseline and Application Cases, a cumulative effects case was assessed. Cumulative effects represent the combined impacts of all previous, existing, and reasonably foreseeable human developments and activities. The influence of previous and existing logging activities within the RSA was considered in the assessment when defining the effect of the Project on a given VC relative to its baseline status. 2.5 Key Issues and Key Questions The Project involves the development and operation of a mine site and supporting infrastructure including roads, stockpile area, sediment control measures (i.e., sediment basins) camp and administration facilities, and a barge-loading facility (Volume 1, Section 4). For each ecological discipline, key issues relating to the Project were identified during the baseline data collection phase, including stakeholder consultation (Volume 1, Section 2). The key issues for the Project were addressed through key questions. Key questions frame relationships between Project-related activities and potential environmental effects. These key questions and the key issues are presented and discussed for each of the ecological disciplines below Geology and Soils In terms of the geology and soils, the following key issues were identified: loss of soil structure and integrity in the Project Area as a result of the mining activities wind and water erosion, compaction from traffic soil mixing dust generation contamination from spills and leaks disturbance of ASS loss of soil seed banks rehabilitation success of disturbed areas Given these key issues, two key questions were formulated; these are presented in Table

30 SMM Solomon Ltd Volume 3 Table 2.5-1: Ecology Key Questions Number Key Questions GS-1 What is the effect of the Project on soil quantity? GS-2 What is the effect of the Project on soil quality? TE-1 What is the effect of the Project on terrestrial ecology? TE-2 What is the effect of the Project on terrestrial species of concern? FE-1 What is the effect of the Project on freshwater habitat valued components? FE-2 What is the effect of the Project on freshwater biological and cultural valued components? ME-1 What is the effect of the Project on marine ecology? Terrestrial Ecology In relation to terrestrial ecology, the following key issues were identified: loss of ecosystem processes, functions and integrity, including microclimate change due to removal of intact rainforest and replacement of that forest with rehabilitated areas of different processes and functions loss of quality and/or quantity of habitats (including critical habitat), populations and communities habitat fragmentation (including critical habitat) due to Project infrastructure loss of individuals and populations of species (including SoC) during clearing operations for the construction and operation phases sensory disturbance (e.g., light, noise, dust) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging) alteration of habitat (including critical habitat) due to changes in air quality (including dust, elevated metals (e.g., Ni, Co) in areas not normally found) increased interactions of fauna species with project activities (including vehicle collisions) effects to movement patterns of fauna and gene flow effects of introduced species (flora and fauna) and diseases increased hunting and resource harvesting pressure due to in-migration and camp followers effects of soil loss and sedimentation loss of soil seed banks effects of accidental pollution on ecosystem integrity Key questions for the terrestrial ecology component are presented in Table The second key question was divided into sub-questions to address effects to each VC (e.g., SoC) identified for the assessment.

31 SMM Solomon Ltd Volume Freshwater Ecology In relation to freshwater ecology, the following key issues were identified: loss of ecosystem processes, functions and integrity, including microclimate change due to removal of intact rainforest and replacement of that forest with rehabilitated areas of different processes and functions loss of quality and/or quantity of habitats (including critical habitat), populations and communities loss of individuals and populations of species (including SoC) altered surface water flow regimes, including diversion of surface flows away from aquatic habitats sensory disturbance (e.g., light, noise, dust) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging) effects to movement patterns of fauna and gene flow effects of soil loss and sedimentation effects of accidental pollution on ecosystem integrity (e.g., eutrophication of watercourses from stormwater run-off leading to algal blooms; hydrocarbon pollution leading to die off of aquatic plants and animals, which in turn affects the systems natural ability for purification of water) introduction of invasive species reduction in potential food resources for local residents increased hunting and resource harvesting pressure due to in-migration and camp followers Two key questions for freshwater ecology were devised, and are presented in Table Marine Ecology Project activities during the construction, operation, decommissioning and closure phases have the potential to affect the marine environment in many ways. The key issues identified include: loss of ecosystem processes, functions and integrity, including altered marine hydrodynamic conditions increased turbidity and sedimentation loss of quality and/or quantity of habitats (including critical habitat), populations and communities loss of individuals and populations of species (including SoC) sensory disturbance (e.g., light, noise, dust) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging) increased interactions of fauna species with project activities (including boat interactions)

32 SMM Solomon Ltd Volume 3 effects to movement patterns of fauna and gene flow effects of introduced species (flora and fauna) and diseases increased hunting and resource harvesting pressure due to in-migration and camp followers effects of accidental pollution on ecosystem integrity, including contamination of the sediments Based on these issues, one key question was derived, which is presented in Table Valued Components Valued components can be physical habitat, biological, economic, social and/or health properties of the environment that are considered important. Valued Components are identified as measurable indicators in regards to the key questions. For terrestrial, freshwater and marine ecology, it is recognised that although all species are important, it is neither practicable nor necessary to assess potential effects of the Project on every species that might be affected. Rather, the assessment concentrates on a set of VCs selected to focus the scope of the assessment in a way that makes it both manageable and meaningful. The VC list represents a carefully considered subset of species identified to act as indicators because the species: have potential for interaction with the Project may be especially sensitive to the Project effects presence, abundance and distribution in the LSA and RSA trigger critical habitat under the IFC PS 6, or are SoC represent guilds of species or habitat relationships that extend beyond the VC capture effects to other species with similar habitat requirements and sensitivities are of socio-economic importance to local people (e.g., hunted species) Geology and Soils No VCs have been defined for geology and soils. Vegetation types and habitats are greatly influenced by the geology and soils of the areas where they occur. Soil conditions define the moisture and nutrient content available to flora species and the resultant fauna assemblages. Therefore, the habitat VCs selected incorporate geology and soils.

33 SMM Solomon Ltd Volume Terrestrial Ecology Six VCs were selected for assessment. These are presented in Table 2.6-1, together with selection rationale. The VCs selected have the potential to trigger CH in most instances. Table 2.6-1: Terrestrial Ecology Valued Components SoC Group Name Reason for Inclusion Orchid Liparis sp. Tubi Tree Xanthostemon melanoxylon Sago Palm Metroxylon salomonense Green Snail Papustyla sp. or Papustyla pulcherrima Russet-tailed Thrush Zoothera heinei Potentially new species. Morphological features of the collected specimen do not conform with all the known species recorded in Solomon Islands, and is considered likely to be a new orchid species. The specimen is currently being held in the Solomon Island herbarium. One individual recorded in lowland forest. Species of cultural importance. Used for carving. Threat status not assessed by IUCN. Fourteen individuals recorded at three different sites in lowland forest, and another individual observed between transects. Species of cultural importance. Used for building and construction materials. Threat status not assessed by IUCN. One individual recorded in lowland forest. Potentially new species. Similar to a species known from restricted distribution in Papua New Guinea and Manus Island (Delsaerdt 2012). This species is protected under CITES (Conservation International 2013) Several individuals found in freshwater swamp/riverine forests. A single specimen of this species was captured. The species captured was forwarded to the American Museum of Natural History (AMNH) for further classification. Initial advice from AMHN indicates that the specimen is Zoothera heinei sub species guadacanal and represents a range extension. One individual recorded in lowland forest. Habitat Lowland Forest Lowland forest was identified as a valued component as total of 24 SoC were identified as utilising this vegetation type and associated habitats during the baseline field investigation and covers approximately 75% of the LSA.

34 SMM Solomon Ltd Volume Freshwater Ecology Twelve VCs were selected for assessment. These are presented in Table 2.6-2, together with selection rationale. The VCs selected have the potential to trigger CH in some instances. Table 2.6-2: Freshwater Ecology Valued Components Group Name Reason for inclusion Habitat Jejevo River (east) High ecological value, and for the most part, they all represent Nuha River Sivoko River Hughukapote River pristine freshwater environments that have the potential for supporting endemic aquatic species. Drain unmodified, native vegetated forest with minimal or no apparent land-use-related effects. Village gardens occur along stream banks in the lower Jejevo River and result in localised nutrient enrichment and excessive filamentous algae growth; however, growth was localised and minor when the whole catchment is considered (Appendix C). SoC Tateidae spp. Species of concern. Endemic and potential new species found in upper catchment tributaries and springs. Deleatidium sp. Macrobrachium spp. and Caridina spp. Batissa violacea Gobiidae (family) Anguilla marmorata Kuhlia marginata Crenimugil crenilabis Widespread and abundant benthic mayfly species with potential sensitivity to potential Project effects (e.g., sediment inputs). Diverse and widespread group of prawn and shrimp (Crustacea) with potential for endemism. Many are migratory and require passage between freshwater and saltwater. Potential sensitivity to potential Project effects (e.g., sediment inputs, barriers, habitat loss). Species of cultural importance (food resource). Filter-feeding bivalve found in the lower reaches of catchments and potentially sensitive to potential Project related effects (e.g., sediment inputs, bioaccumulation of contaminants). Gobiidae family of fish are important components of Solomon Islands fish fauna and are indicators of pristine environments. Includes both widespread and abundant species (Stiphodon rutilaureus) and those more common in upper catchments (Sicyopterus sp. 1). Includes some potential species of concern (i.e., taxonomically uncertain, Data Deficient) status (Sicyopus discordipinnis, Stiphodon semoni, Sicyopterus sp. 1 and Sicyopterus sp. 2) (IUCN 2013). Species of cultural importance (food resource). Kuhlia marginata (flagtail) widespread and abundant. Anguilla marmorata (eel) is fish that migrates up into small headwater streams to live as large adults. Crenimugil crenilabis (mullet) common in mid-lower reaches in the LSA.

35 SMM Solomon Ltd Volume Marine Ecology Twenty-two VCs were selected for assessment. These are presented in Table 2.6-3, together with selection rationale. The VCs selected have the potential to trigger CH in some instances. Table 2.6-3: Marine Ecology Valued Components Group Name Reason for Inclusion Habitat Mangroves Mangroves are an important habitat for subsistence use providing a major source of dietary protein, including mangrove mud shellfish, mud crab and fish. SoC Seagrass meadows Coral reefs Deep, low-profile reefs Dugongs (Dugong dugon) Long-beaked common dolphin (Delphinus capensis) Orca, killer whale (Orcinus orca) Spinner dolphin, longbeaked dolphin (Stenella longirostris) Indo-Pacific bottlenose dolphin (Tursiops aduncus) Omura s whale (Balaenoptera omurai) Bryde s whale (Balaenoptera edeni) Providing food and refuge for a wide variety of marine fauna (including species of conservation concern such as dugongs and sea turtles) and nursery areas for juvenile fish, including the endangered species. One of the dominant marine ecosystems in Solomon Islands and form part of the Coral Triangle, which is a recognised region of global ecological importance due to high species and ecosystem diversity. Coral reefs provide food and shelter for a large variety of animals, and act as breeding grounds for many marine species. Coral reefs also play a critical role in protecting shorelines from storm damage and erosion. Coral reefs in the LSA were found to support many coral SoC, and habitat for fish SoC, for example, humphead wrasse (Cheilinus undulates). foraging areas for the critically endangered hawksbill turtle (Eretmochelys imbricata) and endangered green turtle (Chelonia mydas), however reefs at alternative locations away from the area of Project activities will be expected to sustain these populations. Deeper reef habitats play an important role in supporting coastal fisheries, on which coastal communities in Solomon Islands heavily depend for both subsistence and income generation. Deeper reefs are also important as refuge areas from environmental disturbance and climate change for corals and associated species. Pavona cactus was observed on deeper low-profile reefs. This species is listed as vulnerable. Vulnerable on the IUCN Red List (IUCN 2013). Known to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have moderate potential to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have moderate potential to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have high potential to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have moderate potential to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have moderate potential to occur in the LSA. Listed as data deficient under the IUCN Red List and considered to have moderate potential to occur in the LSA.

36 SMM Solomon Ltd Volume 3 Table 2.6-3: Marine Ecology Valued Components (continued) Group Name Reason for Inclusion Green turtle (Chelonia mydas) Hawksbill turtle (Eretmochelys imbricata) Olive Ridley turtle (Lepidochelys olivacea) Leatherback turtle (Dermochelys coriacea) Requiem sharks (Carcharhinus melanopterus and Triaenodon obesus) Wrasse (Cheilinus undulatus) Corals Bruguiera hainesii Fish Reef macroinvertebrates Estuarine and mangrove macroinvertebrates Endangered on the IUCN Red List (IUCN 2013). Observed in the LSA during the Project marine water quality baseline survey, conducted in Critically endangered on the IUCN Red List (IUCN 2013). Observed in the LSA during the Project marine water quality baseline survey, conducted in Listed as vulnerable under the IUCN Red List and considered to have moderate potential to occur in the LSA. Listed as vulnerable under the IUCN Red List and considered to have high potential to occur within the LSA. Near threatened on the IUCN Red List (IUCN 2013). Recorded in the LSA during the marine ecology baseline survey. Endangered on the IUCN Red List (IUCN 2013). Sedentary, reef-attached fish, often found in the same areas of reef for long periods. coral reef habitats provide valuable habitat for juveniles, the loss of coral reefs may impact their survival. Recorded in the LSA during the marine ecology baseline survey. Ten vulnerable or near threatened coral species on the IUCN Red List (IUCN 2013). Additional species of conservation concern may occur in the LSA; however, as the lowest taxonomic resolution typically used in the baseline survey for corals was genus, more detailed information is required to identify whether additional species of conservation concern are present. Critically endangered on the IUCN Red List (IUCN 2013). However, the extent of occurrence of this species within the LSA is uncertain owing to the difficulty in separating the identity of this species from the common Bruguiera gymnorhiza species. It is estimated to number fewer than 250 mature plants and is possibly range-restricted. Target food fish in estuarine, shallow reef, deeper reef and pelagic habitats. important subsistence fisheries for households in the vicinity of the LSA. Reef macroinvertebrates, including, bêche-de-mer (all species), bivalves (clams, oysters), crustaceans (lobsters) and gastropods (trochus, false trochus). important subsistence fisheries for households in the vicinity of the LSA. Beche-de-mer (known more broadly sea cucumbers) is also harvested locally for commercial sale to overseas markets. Including mud clams, mud snails, mud crabs and mud lobster. Important subsistence fisheries for households in the vicinity of the LSA.

37 SMM Solomon Ltd Volume Biological Indicators Incremental effects of the Project on ecology VCs were evaluated using indicators. Indicators represent properties of the VC, that when changed, can result in, for example, changes in abundance and distribution of the VC. Indicators were evaluated quantitatively where possible (e.g., predicted changes in habitat quantity and quality, loss of species population), but were assessed qualitatively where data were unavailable (e.g., predicted changes in survival and reproduction). Indicators for the ecological disciplines are presented below Geology and Soils Indicators for effects on geology and soil VCs are: soil quantity (the availability of soil for vegetation and rehabilitation) soil quality (the ability of soil to sustain vegetation) Terrestrial Ecology Indicators for terrestrial ecology are: habitat quantity and quality habitat connectivity species abundance and distribution Freshwater Ecology Indicators for freshwater ecology are: habitat quantity and quality habitat connectivity species abundance and distribution Marine Ecology Indicators for marine ecology are: habitat quantity and quality species abundance and distribution

38 SMM Solomon Ltd. 3-1 Volume MITIGATION This section outlines mitigation measures to avoid or minimise potential effects on ecology associated with the Project interactions described in Section 5. Environmental design features will follow environmental best practice and management policies and procedures, and adhere to the mitigation hierarchy described below: avoidance to reduce effects actions to minimise effects rehabilitation or repair an effect actions to compensate for effects that cannot be mitigated Discipline-specific mitigation measures for the design of the Project are presented and discussed below. The application of these mitigation measures is undertaken before the effects assessment and impact classification is done. This then results in the residual effects that project may have on ecological VCs, that is, effects that will require additional management and monitoring during the life of the Project. 3.1 Geology and Soils The mitigation measures proposed to avoid and minimise effects on the geology and soils are presented in Table Table 3.1-1: Geology and Soils Mitigation Measures Mitigation Category Project Phase Mitigation Measures Vegetation clearing, topsoil/subsoil exposure, infrastructure construction Minimisation of the area requiring vegetation clearing, operation of machinery and construction infrastructure. Preparation of a pre-clearing plan prior to construction that details clearing protocols. Maximisation of topsoil separation and preservation for use during rehabilitation Suitable stockpiling of topsoil during the construction phase for re-use during rehabilitation. Minimisation of the soil profile degradation by reducing operational traffic. Erosion and sediment control measures implemented including: sediment fencing along waterways to limit loss of soil into creeks due to overland surface water flow use of sediment detention basins to capture suspended sediment in surface water Undertake environmental values and protocols training of all staff as part of site inductions. Implementation of an environmental monitoring program.

39 SMM Solomon Ltd. 3-2 Volume 3 Table 3.1-1: Geology and Soils Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Site preparations to avoid Traffic control and protocols in place to loss of soil structure, waste management minimise trafficable area and soil compaction. Implementation of a waste management plan. Decommissioning and Closure Disturbance of acid sulfate soil (ASS) Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Installation of dedicated refuelling stations. Proper vehicle maintenance to minimise the risk of leaks and discharges. Adequate bunding of chemical hazard risk areas. Development and implementation of appropriate emergency response procedures in the event of a hydrocarbon/other liquid spill (e.g., maintaining spill kits in workshops, camps, storage areas). Rapid response time for spills and other loss events in the Project Area to minimise the exposure of soils to contamination. Set up of a spill location and response register. Management of dust during the Project activities (e.g., dust suppression) to limit the potential for migration of contamination through deposition of contaminated soil particles from the air. Soil disturbance avoidance in the areas potentially affected by ASS (e.g., mangrove swamps). Where disturbance is unavoidable, a detailed ASS investigation to assess the necessary management measures to prevent environmental harm is to be undertaken prior to ASS disturbance. Maintain fertility of stockpiled topsoil for re-use during rehabilitation.

40 SMM Solomon Ltd. 3-3 Volume 3 Table 3.1-1: Geology and Soils Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Removal of site equipment, site remediation, reclamation Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Set up of decommissioning and closure plans and protocols to optimise site rehabilitation and reclamation. Optimisation of reuse of topsoil for rehabilitation. Undertaking soil investigations of potentially contaminated locations (for instance identified by the spill and response register) prior to clean-up. Undertaking site remediation validation. 3.2 Terrestrial Ecology The mitigation measures proposed to avoid and minimise effects on the terrestrial ecology are presented in Table Table 3.2-1: Terrestrial Ecology Mitigation Measures Mitigation Category Project Phase Mitigation Measures Land clearance leading to habitat fragmentation, edge effects (vegetation gaps) and loss of soil seed bank Operation Operation Operation Operation Decommissioning and Closure Preparation of a pre-clearing plan prior to construction and operation that minimises clearing areas and details clearing protocols to minimise effects on surrounding habitats and fauna. Clear identification of clearing limits on plans and on the ground (internal permits authorised by site supervisors (Permit To Work (PTW) system) flagging, signage). Staged clearing and progressive rehabilitation. Areas under rehabilitation clearly marked (e.g., flagging, signage). Critical fauna assessments at locations proposed for infrastructure locations to assess for fauna habitat (particularly endemic and threatened species). Establishment of nurseries to raise seedlings and wildlings for future re-vegetation activities where possible. Searches for SoC will be undertaken prior to clearing, relocation of species (including orchids) will be undertaken as practicable. Transport of habitat features such as large logs and boulders to create new fauna refuge sites. Decommissioning and dismantling of Project infrastructure to revert the land to its original use (in accordance with the Project s Mine Rehabilitation and Closure Plan).

41 SMM Solomon Ltd. 3-4 Volume 3 Table 3.2-1: Terrestrial Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Rehabilitation of areas to include forest regeneration and Operation re-vegetation techniques. Offset options to compensate for mine blocks that cannot Operation be readily restored through regeneration/revegetation of logged over areas within the Project Area. Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Vegetation and threatened species monitoring. Development of an environmental education package for both personnel and communities that highlights conservation issues and species-specific sensitivities. Rehabilitation of disturbed sites with native species to approximate pre-existing vegetation. As soon as an area (including roads) is no longer required for the Project, to be rehabilitated as soon as practical. Undertake weed management programs as part of rehabilitation programs. Rehabilitate edge areas as soon as practicable. Spotter catchers to assess all areas immediately prior to clearing and be present during clearing to move on/recover fauna in the clearing area. Restrict mine personnel pedestrian traffic on the access road in the mining area to minimise disturbance to fauna. Prohibit workers from getting out of vehicles while in transit to their work area to minimise disturbance to fauna. Restrict workers to their designated work area and facilities. Construct road culverts to be also used as fauna (i.e., small reptiles, mammals) migration corridors and install at regular intervals.

42 SMM Solomon Ltd. 3-5 Volume 3 Table 3.2-1: Terrestrial Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Operation Site works leading to accidental pollution Site establishment and operations leading to overhunting and uncontrolled vegetation clearing due to population influx Site activities leading to noise emissions and vibration Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Operation Operation Decommissioning and Closure Operation Operation All cleared topsoil to be replaced/reused for rehabilitation purposes as soon as practical (immediately where viable) or stored appropriately to retain seed soil banks. Appropriate storage and handling of all potential pollutant materials. Implementation of waste management plan. Appropriate monitoring and service of all project vehicles and machinery to minimise potential spills. Appropriate chemical spill response procedure in place. Dedicated fuelling stations. Allow for pre-harvesting and storage of identified cultural important flora (e.g., tubi, sago). Implement a strict no hunting and forest clearing procedure for SMM Solomon personnel. Development of an environmental education package for both personnel and communities to highlight the importance of biodiversity and practical tips on how individuals can participate in conservation. Monitor movements of locals in previously inaccessible areas via project infrastructure. Strict controls on vehicle speeds on internal roads. Maintain internal roads in good working order. Ensuring all vehicles, plant and machinery are maintained in proper working order to avoid unnecessary engine, motor or muffler noise.

43 SMM Solomon Ltd. 3-6 Volume 3 Table 3.2-1: Terrestrial Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Ensuring all vehicle and plant operators are aware of the Operation location of sensitive receptors and the measures required for limiting noise where possible. Site activities resulting in artificial light Vehicle movements resulting in collisions with fauna Site activities leading to increases in dust and changes to air quality Vegetation clearing and construction activities leading to increases in soil erosion Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Operation Minimal lighting where practical, restrict lighting to only those areas that are identified as being required. Anti-glare lighting to minimise disruption to the vision of nocturnal wildlife (e.g., bats, owls, reptiles), where practical. Use of anti-glare sleeves or shields to control/manage the direction of light from vehicle headlights, where practical. Use of light sources with directional lighting and screens to concentrate light on operations, where feasible. Relocation of wildlife attracted to lighting sources to their natural habitat and away from Project facilities. Strict controls on vehicle speeds on internal roads. Record all wildlife strikes to determine the species prone to vehicle strikes, specific areas where accidents commonly take place, and at what time. In strike-prone areas, use of exclusion fences, culvert crossings, suppression of attractive vegetation that could provide food/shelter/nesting sites to fauna. Displaying signs to drivers where fauna regularly cross roads/tracks. Enforcement of road rules. Driver training. Maintain moist working surfaces (e.g., roads, excavation areas, bare ground). Utilising boundary water sprays while excavating, where practical. Minimising soil drop height. Maintaining ore moisture above relevant Dust Extinction Moisture Level. Minimising works during high wind periods. Stabilising the soil using effective engineering design and measures. Staging clearing, construction and mining, and mining in blocks/parcels to minimise the total area to be disturbed at any one time.

44 SMM Solomon Ltd. 3-7 Volume 3 Table 3.2-1: Terrestrial Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Progressive rehabilitation including backfilling, topsoil Operation management, natural regeneration and/or revegetation. Site establishment and operations leading to the introduction of invasive species, feral animals and/or exotic species Site activities leading to changes in water quality and groundwater Operation Operation Operation Decommissioning and Closure Operation Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Operation Decommissioning and Closure Use of silt and sediment traps proximal to construction and earthmoving activities to minimise sedimentation in downslope areas. Ensuring compliance with national quarantine requirements. Development and implementation of a local quarantine procedure plan to detect and prevent introduction of invasive species, weed, feral animals and/or exotic species. Undertaking environmental monitoring surveys to detect invasive, weed, feral animal and/or exotic species. If introduced species are detected, an investigation will be carried-out to ascertain the species, place of origin and possible mode of transfer. Development of an environmental education package for both personnel and communities to highlight the issues relating to introduced species. Monitor and record introduce species populations within the Project facilities to identify species that are increasing in population. Monitor and remove all identified exotic species from the area until after project closure. Maintain surface water quality and quantity to standards.

45 SMM Solomon Ltd. 3-8 Volume Freshwater Ecology The mitigation measures proposed to avoid and minimise effects on the freshwater ecology are presented in Table Table 3.3-1: Freshwater Ecology Mitigation Measures Mitigation Project Phase Category Land clearance Road runoff and river crossings Surface water diversions Sediment basin discharges Chemical spills and leakages Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Mitigation Measures Minimise area requiring vegetation clearance where possible (especially along riparian margins). Install sediment fencing along waterways to reduce sediment inputs to watercourses. Surface runoff from areas generating sediment to be collected in pocket ponds/sediment basins. Test stormwater quality discharges to the aquatic receiving environment Roads will be designed to avoid waterways (where possible) to reduce number of river crossings. Project roads to be sheeted to appropriate depths with material sourced from borrow pits (Volume 1, Figure 4.3-3). Post-mined areas to be rehabilitated (re-contoured and re-vegetated) as soon as practicable. Avoid as much as possible the disturbance of steep headwater gullies. Minimise riparian vegetation clearance, but when unavoidable, avoid the dumping of large quantities of woody debris (slash) into waterways. River crossings to be designed to afford passage for migratory shrimp, prawn and fish. Culverts will be designed and installed following best practice guidelines to allow for passage for migratory shrimp, prawn and fish (avoid perched culverts). Design and implement guidelines that minimise disturbance of aquatic habitat and cause potential mobilisation of sediment during construction. Apply appropriate sediment control measures (e.g., pocket ponds, inside and outside gutters, check dams). As much as practicable, construct river crossings during dry weather. Rehabilitate riparian vegetation in the works area as soon as practicable. Construct surface water diversion channels prior to vegetation clearance and earthworks to avoid uncontrolled runoff into watercourses. Design/construct diversion channels in a way that captures natural surface water runoff prior to entering cleared areas and divert to watercourses to minimise potential for reductions in flow in watercourses. Riparian planting along diversion channels after construction to increase shading (water temperature control) and to provide a potential source of aquatic habitat and food (i.e., woody debris, leaf litter). Implement sediment control measures during the construction and operation phases including pocket ponds and sediment basins following best practice guidelines. Monitor discharge flow and water quality from sediment basins prior to discharge and cease discharging when applicable guidelines are exceeded. Incorporate design features, management practices and mitigation plans to minimise spills. Develop and implement appropriate emergency response procedures in the event of a chemical spill or leakage and maintain spill kits in workshops, camps and storage areas.

46 SMM Solomon Ltd. 3-9 Volume 3 Table 3.3-1: Freshwater Ecology Mitigation Measures (continued) Mitigation Project Phase Mitigation Measures Category Water supply intakes Ore stockpile runoff Install a modern water intake structure and screen that is designed to reduce the potential for entrainment and impingement of biota (screen openings should be <3 mm wide). Intake screens to be set parallel to river flow and with deflector cones on the intake structures. Intakes located in areas that avoid biota (e.g., river margins, middle and near streambed). Water intake screens should have sweep velocities (across the screen) more than 0.5 m/s and approach velocities (into the screen) less than 0.3 m/s to reduce entrainment and impingement. Water take volumes to be managed to avoid changes in flow regime and aquatic habitat available. Diversion channels to divert runoff from ore stockpile area to appropriately sized sediment basins for treatment prior to discharge. Treated water held in sediment basins to be reused where possible or discharged to the receiving environment at a flow rate that does not adversely affect flow regime and aquatic habitat. Discharged stormwater to be treated and tested prior to discharge to make sure guidelines are met for appropriate parameters of concern (e.g., TSS, ph, metals and metalloids).

47 SMM Solomon Ltd Volume Marine Ecology The mitigation measures proposed to avoid and minimise effects on the marine ecology are presented in Table Table 3.4-1: Marine Ecology Mitigation Measures Mitigation Project Phase Category Increased Turbidity and Sediment Direct Loss of Marine Habitat Mitigation Measures The Erosion and Sediment Control systems for the mine area will be designed to maintain the sediment levels, frequency and duration consistent with the natural turbidity regime. Floating silt barriers and turbidity curtains will be used during jetty construction to contain turbid water. These are floating barriers that are designed to prevent the movement of turbid water beyond the construction zone. Drainage controls will be implemented in the area of the ore stockpile, accommodation camp, mine administration area, fuel and chemical storage, and jetty facility to collect runoff and direct it to a sediment control pond, which will include filter dam, spillway and dewatering system. Drainage controls will be designed to maintain the sediment levels, frequency and duration consistent with the natural turbidity regime. Silt curtains will also be installed to restrict runoff from ore stockpiles entering marine waters, where necessary. Marine traffic movement measures will include: Limiting vessel movements to within the transhipment mooring location and designated channels. Containing marine traffic in waters of sufficient depth to avoid resuspension of sediment due to propeller action. Barge design that minimises influence on seafloor by having shallow draft, suitable hull profile and systems to provide for low wake and high manoeuvrability. The ore handling system will include: Water spray or windbreak systems to reduce generation of fugitive dust during ore transfers. Spillage-free loading chutes and grabs to unload barges. Areas of mangrove to be cleared for infrastructure will be kept to a minimum. Pre-clearance surveys will be undertaken by a qualified botanist of any areas in the Project footprint where mangrove is to be cleared to identify if the critically endangered mangrove species Bruguiera hainesii is present. If so, alternative locations will be selected for infrastructure, where practicable, or otherwise suitable offsets provided. Marine traffic movement measures will include: Limiting vessel movements to within the transhipment moorage location and designated channels. Containing marine traffic in waters of sufficient depth for navigation. Setting and enforcement of vessel speed limits.

48 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures All shipping routes and the location of the transhipment mooring require verification for safe navigation by a suitably qualified marine authority. Shipping channels for the transhipment mooring, ore loading/supply jetty and passenger jetty shall be clearly defined by channel markers equipped with navigation lights. The transhipment mooring will be established on bare substrate rather than on areas supporting deeper reef using fixed moorings to limit the impacts of anchors. Vessel speed limits will be enforced in designated areas (sensitive receptors/ shallow water/ near shore areas) to avoid erosion due to vessel wake and to reduce propeller wash. Contain vessel traffic to deepest water, wherever possible. Underwater Noise Pile installation for the jetties should avoid periods of peak local marine mammal and turtles abundance, (e.g., during migratory or breeding seasons), if practicable. Light Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Installation of jetty piles using bored piling instead of other piling methods to avoid the generation of high frequency underwater noise. Bored piling involves the boring of a hole using specialised equipment. A reinforced pile is then constructed in-situ in the bored hole using concrete. of the marine structures will begin onshore and will advance seaward, allowing for an extended period of response time by acoustically sensitive marine mammals in the area (by means of avoidance or habituation). Mitigation measures described in the noise impact assessment (Volume 5, Section 2) will also be implemented, including muting noise of equipment used on vessels. A pre-start check for marine mammals and turtles will be done immediately prior to commencement of piling operations. Marine mammal and turtle monitoring will be implemented during piling activities by a suitably qualified observer. A 500 m safety perimeter shall be visually monitored around the piling operations to monitor for presence of main mammals and turtles. Piling will not be undertaken if marine mammals or turtles are sighted within 500 m of the work area. Noise insulation measures will be identified as part of the marine piling activities and other marine based activities. To minimise potential effects on turtle nesting activities, the external spill of light from marine vessels and infrastructure will be reduced as much as practicable to the minimum required for safety and by directing light to reduce external visibility of light sources.

49 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Project Phase Mitigation Measures Category Introduced Marine Pests Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Management measures that comply with International Maritime Organization (IMO) conventions (IMO 2004) and industry good practice will be implemented to mitigate the risk of marine pest incursions, including: Ballast exchange in mid-ocean. Regular hull hygiene maintenance and inspection. Inspection (and treatment as necessary) of any cargoes or packaging that could introduce marine pests. Ballast water should only be discharged in Solomon Islands waters if the ship s master has demonstrated that the ballast water: Has been exchanged en route to Solomon Islands in areas free from coastal influences, preferably 200 nautical miles from the nearest land and in water over 200 m in depth. Accepted techniques are either emptying and refilling ballast tanks/ holds with an efficiency of 95% volumetric exchange or pumping through the tanks a water volume equal to at least three times the tank capacity. Tanks should be pumped no more than two at a time and, if two tanks are pumped together, they should be a symmetrical pair of tanks to make sure the safety of the vessel. Is fresh water (not more than 2.5 parts per thousand sodium chloride). Has been treated using an appropriate shipboard treatment system. Sediment that has settled in ballast tanks, ballasted cargo holds, sea-chests, anchor lockers or other equipment must not be discharged into Solomon Islands waters. If the ship needs to discharge sediment, the sediment must be landed and taken to a landfill. Surveillance for marine pests in the LSA, particularly in areas of high marine traffic (i.e., jetties and mooring locations) will facilitate early detection and opportunities for population management of potential marine pest species that have transferred from vessel biofouling into the marine environment. Surveillance monitoring should include formal biannual surveys as well as informal surveys by community members who are interested in attending training and who are willing to undertake surveillance through incidental observations made as part of normal daily routines.

50 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Altered Marine Hydrodynamics Decommissioning and Closure Project shipping activities will adhere to the IMO s Marine Environment Protection Committee (MEPC) Resolution.207(62) titled the 2011 Guidelines for the Control and Management of Ships Biofouling to Minimise the Transfer of Invasive Aquatic Species, including keeping records of biofouling management practices. Anti-fouling systems and operational practices are the primary means of biofouling prevention and control for existing ships' submerged surfaces, including the hull and niche areas. The biofouling management plan should address, among other things, the following: details of the anti-fouling systems and operational practices or treatments used hull plans to identify locations susceptible to biofouling, schedule of planned inspections, repairs, maintenance and renewal of anti-fouling systems dates and location of dry-dockings/slippings, and any measures taken to remove biofouling or to renew or repair the anti-fouling system the date and location of in-water inspections, the results of that inspection and any corrective action taken to deal with observed biofouling Consideration should be given to the hull and niche areas which can be particularly susceptible to biofouling growth including sea chests, dry-docking support strips, bow and stern thrusters, edges and weld joints, rubber hinges and stabiliser fin apertures, propeller and shaft, stern tube seal assemblies and the internal surfaces of rope guards, cathodic protection anodes, sea inlet pipes and overboard discharges. To maintain a ship as free of biofouling as practical, it is advisable for the ship to undertake in-water inspection, cleaning and maintenance, preferably in the port of origin as close as practical prior to departure. In-water cleaning can also introduce different degrees of environmental risk, depending on the nature of biofouling, the amount of anti-fouling coating system residue released and the biocidal content of the anti-fouling coating system. Therefore, ship maintenance facilities should adopt measures to ensure that viable biofouling organisms or chemical and physical pollutants are not released into the local aquatic environment. Training for ships' masters and crews, in-water cleaning or maintenance facility operators and those surveying or inspecting ships as appropriate should include instructions on the application of biofouling management and treatment procedures, based upon the information contained in the IMO Guidelines. Minimise footprint of marine infrastructure (e.g., open framed infrastructure such as piled jetty rather than solid infrastructure) to minimise disturbance of natural current and wave regime.

51 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Project Phase Mitigation Measures Category Contamination of Water and Sediment Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure An emergency response plan will be developed and implemented that will: Include a spill response plan for oil and hazardous substances. Provide for training of staff as part of the induction process to facilitate awareness of responsibilities and educate on identification of risks and sources of potential chemical and fuel spills and implementation of appropriate control and response measures and reporting requirements. A mobile oils spill kit will be maintained and available for deployment by the port workboat in the event of a spill to marine waters. A hazardous materials register will be developed and implemented. Hazardous waste will be handled, transported and removed by appropriately trained staff members to an appropriately licensed facility offsite. The amount of hazardous materials kept on board vessels will be minimised and will be kept under appropriate storage conditions. Wastes produced by vessels that cannot be discharged under MARPOL (a) will be stored on board for transfer to an approved onshore facility for disposal. A waste management plan will be developed that will implement international leading practice for waste management. All waste storage infrastructure will be designed to make sure it is suitable for use, corrosion resistant and prevents spills from entering water management systems. Procedures will be incorporated into the construction and operation to make sure waste is handled and stored in accordance with applicable standards and that spill management kits, personal protective equipment and relevant operator instructions and emergency procedures are made available. All hydrocarbons and chemical reagents will be stored and handled in accordance with the relevant Material Safety Data Sheets (MSDS), including storage in safe, bunded areas.

52 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Vehicle refuelling will be undertaken in designated areas. Decommissioning and Closure Potentially oily runoff from areas such as equipment laydown areas and re-fuelling areas will be contained within perimeter Decommissioning bunding. and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure All vehicles and marine vessels will be properly maintained to prevent leaks of hydrocarbons Wastewater will be treated in a sewage treatment plant with effluent discharges managed in accordance with International Finance Corporation (IFC) General Environmental, Health and Safety Guidelines (IFC 2007) (such as reuse of wastewater for irrigation at the camp and disposal of sludge at a landfill site). Marine traffic movement measures will include: Limiting vessel movements to within the transhipment moorage location and designated channels. Containing marine traffic in waters of sufficient depth for navigation. Setting and enforcement of vessel speed limits. Shipping channels for the transhipment mooring, ore loading/supply jetty and passenger jetty shall be clearly defined by channel markers equipped with navigation lights. Drainage controls will be implemented in the area of the ore stockpile, accommodation camp, mine administration area, fuel and chemical storage, and jetty facility to collect runoff and direct it to a sediment control pond, which will include filter dam, spillway and dewatering system. The water retained in the drainage controls will be tested prior to release to make sure it is of suitable quality for release to the environment. Release of the water will occur over a large, flat vegetated area to encourage further filtration through the soil before the water meets groundwater. Silt fences/ curtains will also be installed to restrict particulates in runoff from entering marine waters, where necessary. Dust levels at the ore stockpiles will be visually monitored and managed using spray irrigation systems, if necessary. The ore handling system will include: Water spray or windbreak systems to reduce generation of fugitive dust during ore transfers, if necessary. Spillage-free loading chutes and grabs to unload barges.

53 SMM Solomon Ltd Volume 3 Table 3.4-1: Marine Ecology Mitigation Measures (continued) Mitigation Category Project Phase Mitigation Measures Water from washing of barge holds will not be discharged to the marine environment. Decommissioning and Closure Collisions with marine mammals and turtles Increased fishing pressure Litter Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Good practice management for ore transfers will be achieved by: Formal task instruction which includes spillage mitigation techniques Employee induction which includes spillage mitigation requirements Visual observations and reporting of spillages to inform site management practices. Sampling for acid sulfate soils analyses will be undertaken in any areas of swamp or mangrove muds that will be disturbed during the construction of infrastructure and appropriate mitigation undertaken, if required. Routine observations will be conducted for marine fauna to allow detection and subsequent avoidance by vessel masters. Marine traffic movement measures will include limiting vessel movements to within designated channels and setting and enforcement of vessel speed limits. The workforce will be banned from fishing or taking marine resources in the area. Any fish purchases from local fisherman to supply food for the workforce will be undertaken in a manner that sustains local marine resources and as part of a sustainable procurement management plan for aquatic resources. The consumption of marine reptiles, mammals, sharks or the humphead wrasse (Cheilinus undulatus) will be prohibited to make sure no effect on species of conservation concern. A waste management plan will be developed that will implement international leading practice for waste management. Waste will be collected and placed in a purpose built refuse area within the camp compound. Bins will be provided to encourage waste segregation and recycling (i.e., separate bins for food waste, general waste and recyclables such as glass, metal and paper). Non-hazardous wastes materials that remain after the implementation of feasible waste prevention, reduction, reuse, recycling and energy recovery methods will be treated and disposed of to a properly designed, permitted and operated sanitary landfill as per IFC General Environmental, Health and Safety Guidelines (IFC 2007). (a) Marpol is the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of ("Marpol" is short for marine pollution)

54 SMM Solomon Ltd. 4-1 Volume EXISTING CONDITIONS This section presents the existing conditions of the ecological environment of the Project Area. These sections represent summaries of the baseline reports for each discipline, which can be found in full in Appendix A to D. 4.1 Geology and Soils The Geology and Soils Baseline Report (Appendix A) describes the characterisation of geological, chemical and physical properties of soils for the Project using field observations and chemical and physical testing. The Santa Isabel and Choiseul Islands have formed at the collision boundary between the Ontong Java Plateau (OJP) of the Pacific Province and the Old Solomon Arc of the Central Province. This collision boundary is marked by the Kia-Kapito-Korighole Fault System (KKKFS). In the northern area of the KKKFS, the OJP is made up of Sigana Basalts overlain by pelagic limestones and volcaniclastic sediments. South of the KKKFS, the Central Province consists of pillowed and massive flows of basalt to andesitic lavas with associated gabbros overlain by clastic sediments. Nickel laterites are developed through residual and supergene enrichment of nickel in the soil and saprolite horizon above low grade ultramafic complexes. The nickel laterite deposits of Solomon Islands have developed under tropical conditions over ultramafic rocks. The laterite profile overlying the ultramafic rocks can be described as a stratigraphic sequence comprising (top to bottom) top soil overlying a Limonite Zone (Limonite-1, Limonite-2, Limonite-3), a Transition Zone and a Saprolite Zone (Decomposed Rock and Highly Weathered Rock). Fifteen soil inspection sites were surveyed and 20 samples were collected. Samples were analysed for physical and chemical parameters including: Moisture Content ph 1:5 and Electrical Conductivity (EC 1:5 ) Selected Total Metals Total Sulfur Total Organic Carbon Exchangeable Cations Soluble Sulfate and Chloride Total Nitrogen and Total Phosphorus Particle Size Distribution (Hydrometer assessment method) One borehole was also sampled for Acid Sulfate Soil (ASS) analysis at three sample depths down the profile. The main results of the analysis program are summarised as follows: Results for metals greater than the average crustal abundance values were reported for arsenic, boron, copper, manganese, antimony, vanadium, zinc and mercury. The Geochemical Abundance Index (GAI) for metals was applied to the results and only chromium and nickel results from the tenement areas were reported to have a GAI of three or greater, indicating some enrichment of the environment.

55 SMM Solomon Ltd. 4-2 Volume 3 The soils show little variation in ph between the topsoil and upper subsoil samples. Samples ranged in ph from 6.2 (slightly acidic) to 4.2 (acidic). Results for ASS indicated the presence of high levels of Actual Acid Sulfate Soil (AASS) in the surface sample (0 to 0.1 m), decreasing with depth. The concentrations of Potential Acid Sulfate Soil (PASS) are indicated by the peroxide oxidisable sulfur results. The concentrations of peroxide oxidisable sulfur in the three samples increased with depth. The resultant net acidity indicated high levels of AASS or PASS in all three samples tested. Soil salinity levels were generally low, with most samples reporting Electrical Conductivity (EC) concentrations between 10 µs/cm and 28 µs/cm. Soluble chloride concentrations in the samples generally ranged between 10 and 50 mg/kg, with some notable exceptions at JS08 (250 mg/kg) and JS36 (190 to 1,410 mg/kg). The Exchangeable cation levels are generally low suggesting poor nutrient holding capacity in the majority of the soil samples tested. Nutrient reserves, including total nitrogen and total phosphorous, are likely to be at moderate to high levels; which are desirable for establishment and growth of plants. Organic matter was generally found to be moderate to high which is desirable for nutrient retention. The nutrients were generally concentrated in the surficial soil layer; in locations with several samples collected per borehole, concentrations of nutrients were observed to decrease by approximately 50% from the topsoil sample to the subsoil sample. Particle Size Distribution (PSD) analysis of the samples showed similar results to the field observations and were generally silts and clays. Existing nutrient and soil structure results from this field investigation indicate that the soils are low in salinity and high in nitrogen and phosphorus. The TOC values for the samples analysed indicate suitable concentrations for use of the soil for rehabilitation. Soils from the LSA were generally characterised by slightly acidic to acidic, low plasticity silts and clays, within the topsoil overlying the limonite profile. Most samples collected in these areas had very thin layers of true developed top soil. Results of exchangeable cation, chloride, sulfate and nutrient analyses, particularly in the low-lying coastal areas, support the identification of two soil profiles: a thin, nutrient rich, slightly acidic soil (to depths of approximately 0.1 to 0.25 m bgl); overlain by a slightly acidic, lower nutrient, leached subsoil which is likely part of the limonite stratum 4.2 Terrestrial Ecology The Terrestrial Ecology Baseline Report (Appendix B) describes the characterisation of terrestrial flora and fauna for the Project using field observations and mapping. Solomon Islands is considered one of the world s hot spots for biodiversity and endemicity. Hawkins and Barron (1991) suggest that this is a result of the Archipelago s complex geological history. Nevertheless, even though the area is a recognised biodiversity hotspot, comprehensive studies on Solomon Islands biodiversity values have not been undertaken.

56 SMM Solomon Ltd. 4-3 Volume 3 The majority of scientific assessment, to date, within Solomon Islands has focused on larger more visible groups, such as, the plants, birds, mammals, amphibians and reptiles Vegetation Communities and Flora Species Diversity and Richness Whitmore (1966) described the vegetation communities of Solomon Islands. Within the LSA and RSA, the vegetation communities surveyed as part of the baseline generally align with those described by that study. In particular, three vegetation communities were identified within the LSA: lowland forest (including low diversity ultramafic/ultrabasic and hill forest) freshwater swamp/riverine forest coastal strand vegetation (mangrove) In terms of species diversity, lowland forests contained the largest average number of trees (70.44) per transect, highest species richness (18.7) per transect, and was the second most diverse after the freshwater swamp/riverine forests. The understorey vegetation covered 47.67% of the ground, and contained the highest species richness of all habitats with 7.44 species per m 2. For freshwater swamps/riverine forests, species richness was determined at 17 tree species per transect. This was less than half the number of trees per transect (29.25) compared to the lowland forests (70.44), and diversity indices were slightly higher than lowland forests. The understorey vegetation was the densest of all communities, and covered 74.6% of the ground. On average, the understory contained 5.8 species per m 2. Coastal strand vegetation (mangroves) contained a similar average of trees per transect (38) to the freshwater swamps/riverine forests, but with only eight species per transect. With a Shannon Index of 1.48 and a Simpson Index of 0.72, the coastal strand vegetation (mangroves) was the least diverse community of the three surveyed. The understorey contained the lowest vegetation cover, with 21.6%, and the lowest species richness, with an average of 4.33 species per m Species Richness and Diversity The two fauna surveys (dry and wet season) targeted selected terrestrial fauna groups (i.e., invertebrates, amphibians, reptiles, birds and mammals) in all three forest communities. Nevertheless, the results do indicate that the LSA supports a high biodiversity, specifically within the lowland forest community. Thirty-five bird species were observed in lowland forests, and 15 in coastal strand vegetation. The number of bird observations ranged between 17 and 46 in the lowland forests, and 17 and 45 in the coastal strand vegetation (mangroves). On average, species richness was similar in both vegetation communities, with an average of in lowland forests and 15 in coastal strand vegetation per site. Fourteen species of amphibians, 19 species of reptiles and six species of bats were recorded in the lowland forests and coastal strand vegetation in the LSA. Unlike the bird data, amphibians, reptiles and bats data were more limited due to very low encounter rates. Therefore, there were insufficient data points to calculate diversity indices other than species richness, and preliminary species inventories for the LSA. Invertebrate samples, that is, butterflies (Lepidoptera), dragonflies and damselflies (Odonata), ants (Hymenoptera), land snail (Mollusca), and other insect samples have not yet been classified and identified. Consequently, the findings for those taxa are not presented here.

57 SMM Solomon Ltd. 4-4 Volume 3 The findings of the baseline surveys confirm the current literature of high levels of biodiversity and endemicity in Solomon Islands and that further studies are likely to identify new species Species of Concern Vegetation surveys recorded two tree species classified by the IUCN as vulnerable (Calophyllum obscurum and Pterocarpus indicus) and potentially a new species of orchid (Liparis sp.). The surveys also recorded individuals of Sago palms (Metroxylon salomonense) and Tubi trees (Xanthostemon melanoxylon) (Photograph 4.2-1), which are culturally important, within the LSA. Photograph 4.2-1: Flower of Tubi (Xanthostemon melanoxylon) Fauna surveys recorded two IUCN-listed vulnerable bird species: the Imitator Goshawk (Accipiter imitator) the Solomon Eagle (Haliaeetus sanfordi); one vulnerable frog species, the Solomon Island Palm Frog (Palmatotrappia solomonis) (Photograph 4.2-2), and one vulnerable bat species, the Lesser Flying Fox (Pteropus mahaganus). Four IUCN-listed near threatened bird species: the Red-knobbed imperial-pigeon (Ducula rubricera), the Beach Stone-curlew (Esacus giganteus), the Solomons Monarch (Monarcha barbatus), the Cockerell's Fantail (Rhipidura cockerelli) (Photograph 4.2-3); and one near threatened reptile species, the gecko Cyrtodactylus solomonensis. A potential range extension for the Russettailed Thrush (Zoothera heinei) was also recorded.

58 SMM Solomon Ltd. 4-5 Volume 3 Photograph 4.2-2: Solomon Islands Palm Frog (Palmatorappia solomonis) Photograph 4.2-3: Cockerell's Fantail (Rhipidura cockerelli)

59 SMM Solomon Ltd. 4-6 Volume Critical Habitat The only confirmed taxa that met any of the five criteria for defining critical habitat (IFC 2012a), was the potential new species of orchid, Liparis sp., and the potentially new species of Green Snail (Papustyla sp. or Papustyla pulcherrima). Both these species meet Criterion II of the CH determination of the IFC, that is, species new to science (IFC 2012a). One individual of the orchid was recorded in the lowland forest community, whilst several individuals of the Green Snail were recorded in the freshwater swamp/riverine forest community. Currently, there is not enough information about the distribution of these taxa throughout Santa Isabel Island, or Solomon Islands, to make an informed decision about their status and CH. Regardless, a precautionary approach has been adopted, and, for this assessment, all lowland forest and freshwater swamp/riverine forest communities within the LSA and RSA are assumed to be CH for these two taxa. It is possible that other species collected and recorded, particularly invertebrates are endemic to Solomon Islands, but current taxonomic limitations mean it was not possible to assign undetermined taxa this status. Similarly, the potential for other vertebrate species to be range-restricted and endemic should not be ruled out. Consequently, a more detailed and comprehensive assessment of CH will be undertaken as a supplement to this ESIA. The following conclusions can be drawn from this preliminary assessment of CH for the terrestrial ecology SoC: all lowland forest and freshwater swamp/riverine forest communities within the LSA and RSA are assumed to be CH for these two taxa additional field studies are required to assess the distribution of these species on Santa Isabel Island detailed taxonomic work is needed to confirm that the species are new to science and endemic to Solomon Islands 4.3 Freshwater Ecology The Freshwater Ecology Baseline Report (Appendix C) describes the characterisation of freshwater systems for the Project using field observations and mapping. The baseline study assessed aquatic habitat, macroinvertebrate and fish in six river catchments (Jejevo, Nuha, Heple, Sivoko, Hughukapote and Ola) over the dry and wet season Aquatic Habitat Rivers surveyed were perennial waterways, with naturally-meandering flow paths that drained largely unmodified native vegetated catchments, resulting in moderate-well shaded channels with the exception of wide lowland reaches. All rivers surveyed drain steep upper catchment terrain transitioning into meandering low gradient mid-lowland reaches. Habitat is typically diverse, comprising runs, riffles and pools with high-energy chutes and waterfalls being a common habitat type in the upper catchment and runs being the dominant midlowland habitat type. All rivers had gravel-dominated streambed with cobbles, boulders and bedrock outcrops common at upper headwater sites. A notable feature of the rivers surveyed was the high proportion of organic matter retained in the channel, including large logs, branches and leaf litter traps against logs and accumulated against streambanks. Macroinvertebrate Communities One-hundred-and-thirteen distinct aquatic macroinvertebrate taxa were recorded during the study across the dry and wet season surveys. Most macroinvertebrates could only be

60 SMM Solomon Ltd. 4-7 Volume 3 described to family level. The most diverse group were aquatic insects followed by Malacostraca and Gastropoda. Highest taxa richness was recorded in the mid Nuha River, and the lowest in the lower Ola River where the streambed comprised less gravel and riffles. Communities recorded from larger catchments (Jejevo, Nuha and Heple rivers) were comparable, but differences were detected between upper and lower reaches. Larger catchments supported different communities to those in lowland river catchments. A sparse community was recorded from the lower Heple River and was a probable siltation-related effect associated with selective logging and sediment inputs in the mid-lower catchment. The most abundant groups were Ephemeroptera (mayflies), Trichoptera (caddisflies) and Crustacea (shrimp, prawn, crab). Ephemeroptera were widespread and abundant across sites and did not decrease downstream. Leptophlebiidae (i.e., Deleatidium sp.) were the most common and widespread Ephemeropteran, whilst Prosopistomatidae and Caenidae had an apparent upper catchment habitat preference and were less abundant overall. Trichoptera were moderately diverse, with a high number of Solomon Islands known endemic Trichopteran fauna recorded during the study. Shrimp (Atyidae) and prawn (Palaemonidae) were a diverse and abundant group and widespread and abundant in larger rivers. Their abundance displayed a general increasing downstream trend in the larger catchments. The crab, Pyxidognathus sp., was recorded in the lower Heple River and was the first record of this species in Solomon Islands. Mollusca were diverse and more abundant in the lower reaches of the larger rivers and in the lowland river catchments. Snails in the family Tateidae were recorded for the first time in Solomon Islands from two tributaries in the upper Nuha River and Heple River catchments. The specimens have been tentatively assigned to a new species and endemic status (Dr Alison Haynes 2013, pers. comm.). The macroinvertebrate fauna was dominated by filtering-collector and gathering-collector functional feeding groups. Scraper and predator abundance increased downstream. Solomon Islands is widely-recognised for high species diversity and high levels of endemism (Polhemus et al. 2008). The biodiversity resources of freshwater systems in Solomon Islands are, however, currently poorly known (Polhemus et al. 2008). Given the known high levels of endemism, it is possible that some of the macroinvertebrates identified to family level are endemic Fish Fauna Forty-three fish species, in 18 families, were collected during the baseline surveys of the LSA. These represented 48% of the known Solomon Islands freshwater fish fauna (Boseto et al. 2013). Species richness and abundance was greatest in the mid Jejevo River, mid Nuha River and upper Heple River. Fish were sparse in the upper reaches of the lowland river catchments, which extend into the mine operational area (i.e., upper Hughukapote, upper Sivoko River). Gobiidae, Eleotridae and Kuhliidae families represented 75% of all fish collected. The most diverse families were Gobiidae and Eleotridae. Gobiidae were more diverse and abundant in larger catchments and sparse in smaller lowland catchments. Glossogobius illimis was the most widespread, and Stiphodon rutilaureus the most abundant Gobioid species. The Gobioid sub-family, Sicydiinae, was widespread and a prominent feature of upper catchment fish faunas. Kuhliidae were widespread and abundant, especially in the Jejevo and Nuha catchments. Anguilliformes recorded included Lamnostoma cf kampeni (Ophichthidae), Anguilla marmorata (Anguillidae) and the moray eel Gymnothorax polyuranodon (Muraenidae).

61 SMM Solomon Ltd. 4-8 Volume 3 Fish communities recorded from rivers in the LSA and RSA were generally of similar composition. However, larger catchments supported statistically different communities than lowland catchments based on species richness and abundance. Communities recorded from upper and lower reaches were also statistically different, whilst communities in mid and lower reaches were more similar. Fish communities were dominated by amphidromous species (Eleotridae, Gobiidae, Rhyacichthyidae and Tetrarogidae), which migrate between freshwater and saltwater environments to complete their life cycles. Marine migrants and stragglers were more common in the lower reaches of lowland river catchments. The mid-sivoko River supported a depauperate fish community, which reflect a downstream barrier to migration (i.e., waterfall) as habitat was not a limiting factor. Specialist invertivores were the most common feeding guild. Herbivore specialists/generalists in the Gobioid sub-family, Sicydiinae, were the dominant feature of upper catchment fish communities and are reliant on thin algal films growing on the streambed as a food resource. Nine species in the six families were classed as potential SoC due to their potential cultural significance as a local food resource (e.g., marbled eel, big-eye trevally, flagtails, mangrove red snapper, mullet, silver grunter and white-dotted grouper). Nine species in six families are listed as Data Deficient in the IUCN Red List of Threatened Species (IUCN 2013). These included Hypseleotris cyprinoides (Eleotridae), Zenarchopterus dispar (Hemiramphidae), Gymnothorax polyuranodon (Muraenidae), Rhyacichthys aspro (Rhyacichthyidae), Epinephalus polystigma (Serranidae) and the four sicydiine gobies Sicyopus discordipinnis, Stiphodon semoni, Sicyopterus sp. 1 and Sicyopterus sp. 2. All the identified fish SoC are widely distributed throughout the LSA and RSA, and none are endemic to Solomon Islands Critical Habitat Assessment The only confirmed taxon that met any of the five criteria for defining critical habitat (IFC 2012a) was the potential new species of Tateidae snail (Gastropoda) (Photograph 4.3-1) recorded from upper tributaries in the Nuha River and Heple River catchments. It is possible that other macroinvertebrates collected are endemic to Solomon Islands, but taxonomic limitations meant it was not possible to assign undetermined taxa this status. Photograph 4.3-1: A Potential New Species of Tateidae Snail (Gastropoda) The catchments where individuals of this species were recorded were some 7.6 km apart. The snails met Criterion 2 of the critical habitat definition (a species new to science) as they represented the first record of Tateidae in Solomon Islands, and are a probable new species, endemic to Solomon Islands (Dr Alison Haynes 2013, pers. comm.). The specimens have

62 SMM Solomon Ltd. 4-9 Volume 3 been tentatively reported as two different species (i.e., Tateidae sp. A and B) due to morphological differences including whorl shape (Bindiya Rashni 2013, pers. comm.). At present, there is not enough information about the distribution of Tateidae snails throughout Santa Isabel Island river catchments or Solomon Islands. Current knowledge of Tateidae snails is that they tend to occur in headwater springs, and are transported downstream during flood events (Dr Martin Haase 2013, pers. comm.). Small springs were not sampled as part of this study, but the locations where individuals were collected also suggests a habitat preference for upper catchment environments. Habitat in the upper Nuha River tributary was characterised as a high-energy environment with a boulder and bedrock dominated streambed substrate with small-medium gravels accumulated along slower flowing channel margins. It was along the slower flowing channel margins where the snail collected. It is worth noting that a smaller side-tributary flowed into the Nuha River tributary survey reach via a steep waterfall and may represent potential Tateidae habitat. The other specimen was recorded from an upper Heple River tributary. Habitat conditions in the upper Heple River tributary were different to those in the upper Nuha River tributary. The upper Heple River tributary was a smaller waterway, with gentle flowing run-riffle-pool habitat sequences under baseflow conditions and a small-large gravel dominated streambed. There were no observed side-tributaries, springs or seeps flowing into the tributary in the vicinity of the survey reach. Uncertainty surrounding the preferred habitat and distribution of the Tateidae snails in the LSA and the RSA is confounded by the notable differences in habitat where the two individuals were found. Given the small number of sites and rivers surveyed on Santa Isabel Island in the LSA and the RSA, it is not possible to map a definitive area of critical habitat for Tateidae snails. A more detailed and targeted investigation is required to determine their distribution and preferred habitat. At this stage, it can only be concluded that species of the Tateidae may have a habitat preference for upper catchment tributaries including springs and seeps (Dr Martin Haase 2013, pers. comm.). The following conclusions can be drawn from this preliminary assessment of CH for the Project: upper catchment tributaries are tentatively classed as CH for Tateidae snails additional field studies are required to assess the distribution and habitat preferences of Tateidae snails on Santa Isabel Island detailed taxonomic work is needed to confirm that the Tateidae snails are new to science and endemic to Solomon Islands 4.4 Marine Ecology The Marine Ecology Baseline Report (Appendix D) describes the characterisation of marine flora and fauna for the Project using field observations and mapping. The marine studies undertaken to describe the baseline conditions in LSA included a series of desktop reviews and field surveys, with the gathered information used to describe marine habitats and fauna in the vicinity of the Project. The habitats surveyed included: mangrove forests

63 SMM Solomon Ltd Volume 3 seagrass beds tidal rivers shallow coral reefs (including fringing, patch and barrier coral reefs) deep lagoon areas (comprised of deeper low-profile reefs and bare substrates) Fauna targeted as part of the baseline surveys included: estuarine fish associated with tidal rivers reef fish associated with shallow fringing, patch and outer barrier passage reefs reef fish associated with deeper low-profile reefs pelagic fish in barrier reef passage areas reef macroinvertebrates of artisanal, subsistence or commercial importance Other fauna of conservation, artisanal, subsistence or commercial importance were considered through desktop reviews Mangroves Species Three main assemblage types were defined in the LSA, with two types found along river margins (tall, stilt mangrove forest and mixed mangrove forest), and one type generally found throughout most open coastal areas (open coast mangrove forest). Twelve mangrove species were identified, which accounts for approximately half of the species previously recorded from the southeast and west of Santa Isabel Island. Bruguiera spp. is the dominant species of all mangrove assemblages in the LSA, while Rhizophora apiculata and R. stylosa are the next most important mangroves for the area. Most other mangrove species are considered to have moderate dominance and density, while some are only sparsely distributed and, therefore, have only low importance within their assemblages. The IUCN-listed critically endangered mangrove Bruguiera hainesii was recorded in the LSA during the baseline survey Seagrass Species Five species of seagrass were recorded in the LSA with most seagrass habitats consisting of three key species: Thalassia hemprichii, Cymodocea rotundata and Enhalus acoroides. All seagrass species recorded are widespread in the Indo-Pacific and Solomon Islands, and most are common members of seagrass assemblages. The findings of the baseline survey are generally consistent with the overall description of seagrass habitats in Solomon Islands. Coral Species Coral reefs are one of the dominant marine ecosystems in Solomon Islands, and form part of the Coral Triangle, which is a recognised region of global ecological importance due to high species and ecosystem diversity. The coral reef assessments focussed on fringing, patch and outer passage (barrier) coral reefs in shallow waters (less than 10 m water depth) of the LSA. Habitats of differing complexities were found within each of these reef types, with 65 hard coral genera, representing 18 families, recorded. The families Faviidae and Fungiidae had the highest number of genera recorded. Other families, such as Acropoidae, Agarididae, Mussidae and Pectinidae are also well represented. Soft corals were also recorded, with the most dominant genera including Sinularia and Lobophytum. These results are generally in agreement with the results of

64 SMM Solomon Ltd Volume 3 previous studies undertaken in the area and are considered to be common and representative of the community types found within the LSA. Nine species of coral that were identified as occurring in the LSA are listed as vulnerable or near threatened under the IUCN s Red List. Coral health assessments indicated that the shallow coral reefs are typically healthy, with coral bleaching and coral disease found to be generally very low Deeper Low-profile Reef Coral Species Deeper low-profile reef patches in the LSA occur within the predominately sand and soft sediment lagoon passage between the barrier reefs and the coastline, where depths range from 20 m to in excess of 60 m. More than 80% of the available hard substrate was occupied by red encrusting coralline algae of the family Corallinaceae. Encrusting corals of the genera Favites, Favia and Pachyseris were observed covering some areas of the hard substrate, with some Pavona cactus (listed as vulnerable by IUCN (2013)) on the upper surfaces. Gorgonian sea fans and sponges (including barrel sponges) were also recorded in the low-profile deep reef patches, while the bare substrate around the patches supported numerous sea whips. These taxa are all filter and suspension feeders, reflecting the low light environment in which they were found. Estuarine Fish Species Estuarine systems are numerous and well developed around the coast of Solomon Islands, occurring as tidal rivers and wider embayments along the shoreline, with many small and isolated from each other by extensive fringing coral reefs. Only a small number of fish were caught during the baseline survey; however, all of the fish caught are typical species of Indo- West Pacific estuaries and have been reported from Solomon Islands estuaries previously. Reef Fish Species Over 90% of the fish observed belonged to ten of the 29 families recorded, and included damselfish (Pomacentridae), fusiliers (Caesionidae), surgeonfish (Acanthuridae), wrasse (Labridae), parrotfish (Scaridae), butterflyfish (Chaetodontidae), goatfish (Mullide), emperors (Lethrinidae), snapper (Lutjanidae) and rabbitfish (Siganidae). Damselfish accounted for almost 40% of all fish observed during the survey, which is consistent with previous studies. Angelfish (Pomacanthidae), bream (Nemipteridae) and trigger fish (Balistidae) were also recorded at all sites but were not within the top ten most abundant families reported. The IUCN-listed endangered humphead wrasse (Cheilinus undulatus), and two near threatened species of requiem sharks were recorded in the LSA. The reef fish on deeper low-profile reefs were examined using baited remote underwater video methods. Twenty-four fish families were recorded in this way. Wrasse and damselfish were found to be the most diverse families, with nine recorded species for each family. Eighteen species of fish were recorded during the baited drops that were not found on the shallower reefs, including trevally, requiem sharks, barracuda, pufferfish, silversides, and one or two species each of surgeonfish, triggerfish, wrasse, emperors, goatfish and damselfish. Many of these species are reportedly considered to be rare to Solomon Islands Marine Mammal Species Thirty-three marine mammals have been recorded from Solomon Islands waters. These include eight baleen whales, four beaked whales and three other toothed whales, seventeen dolphin species and the dugong. The following species have been identified as having the highest potential to occur in the LSA:

65 SMM Solomon Ltd Volume 3 pantropical spotted dolphin (Stenella attenuata) spinner dolphin (Stenella longirostris) bottlenose dolphin (Tursiops truncatus) dugong (Dugong dugon) Marine Reptile Species Twelve marine reptiles have been reported from Solomon Islands, including five turtles, six sea snakes and the salt-water crocodile. The following have been identified as having the highest potential to occur in the LSA: green turtle (Chelonia mydas) hawksbill turtle (Eretmochelys imbricata) salt-water crocodile/estuarine crocodile (Crocodylus porosus) leatherback turtle (Dermochelys coriacea) wart snake (Acrochordus granulatus) yellow-lipped sea krait (Laticauda colubrina) brown-lipped sea krait (Laticauda laticaudata) Fisheries Resources The major fisheries resources used by households in the vicinity of the LSA include fish (estuarine, reef and pelagic), mud crabs, reef macroinvertebrates, mud snails and mud clams. Twenty genera of target food fish were recorded in the LSA from observations made at estuarine, shallow coral reef, deeper reef and pelagic habitats. Reef macroinvertebrates of subsistence or commercial importance were also recorded in the LSA. Mud clams, mud snails, mud crabs and mud lobsters are known to be present in the LSA, and have been identified as important subsistence fisheries through the Social Resources baseline survey (Volume 4, Section 1.4 and Volume 4, Appendix A) Habitats Mangroves are an important habitat for subsistence use providing a major source of dietary protein, including mangrove mud shellfish, mud crab and fish. Coral reefs are one of the dominant marine ecosystems in Solomon Islands and form part of the Coral Triangle, which is a recognised region of global ecological importance due to high species and ecosystem diversity. Coral reefs provide food and shelter for a large variety of animals, and act as breeding grounds for many marine species. Coral reefs also play a critical role in protecting shorelines from storm damage and erosion. Coral reefs in the LSA were found to support many coral SoC, and provide habitat for humphead wrasse (Cheilinus undulates), which is listed as endangered on the IUCN Red List (IUCN 2013). Humphead wrasse is a sedentary species often found in the same areas of reef for long periods. Given that humphead wrasses (Cheilinus undulates) are reefattached fish, and that coral reef habitats provide valuable habitat for juveniles, the loss of coral reefs may impact their survival. As such, this habitat is considered critical habitat. Coral reef habitats are also known foraging areas for the critically endangered hawksbill turtle (Eretmochelys imbricata) and endangered green turtle (Chelonia mydas); however,

66 SMM Solomon Ltd Volume 3 reefs at alternative locations away from the area of Project activities are expected to form part of the feeding grounds for individuals of these species too. The seagrass meadows in the LSA and RSA play a vital role in the marine ecosystem, including providing food and refuge for a wide variety of marine fauna (including SoC, such as dugongs and sea turtles) and nursery areas for juvenile fish, including the endangered humphead wrasse. The overall sensitivity of these habitats is, therefore, considered to be high given that coral reefs and seagrass in the LSA are a critical habitat for the endangered humphead wrasse (Cheilinus undulates), and the possible presence of the critically endangered Bruguiera hainesii species in mangrove communities Species of Concern The critically endangered hawksbill turtle (Eretmochelys imbricata) and endangered green turtle (Chelonia mydas) were observed in the LSA during the marine water quality survey, conducted in Humphead wrasse (Cheilinus undulatus) and requiem sharks (Carcharhinus melanopterus and Trianodon obesus) were also recorded in the LSA. Humphead wrasse are listed as endangered on the IUCN Red List, while both species of requiem shark are listed as near threatened. Dugongs (Dugong dugon) are also known to occur in the LSA. This species is listed as vulnerable under the IUCN Red List. A number of other species of marine mammals and reptiles that are listed as either endangered, vulnerable or near threatened, are considered to have moderate to high potential to occur in the LSA. There were ten species of coral that were identified as occurring in the LSA that are listed as vulnerable or near threatened under the IUCN s Red List. Additional SoC may occur in the LSA; however, as the lowest taxonomic resolution typically used in the baseline survey for corals was genus, more detailed information is required to identify whether additional SoC are present. The mangrove species Bruguiera hainesii is currently listed as critically endangered on the IUCN Red List because of an extremely high risk of extinction (it is estimated to number fewer than 250 mature plants and is possibly range-restricted). The presence of Bruguiera hainesii in the LSA has been confirmed by taxonomic experts based on samples collected. However, as described above, the extent of occurrence of this species within the LSA is uncertain owing to the difficulty in separating the identity of this species from the common Bruguiera gymnorhiza species. Bruguiera gymnorhiza is considered to contribute the majority of the trees identified for this species complex based on its common occurrence in previous studies. Numerous marine fauna species listed as data deficient on the IUCN Red List are known, or have a moderate to high potential, to occur in the LSA. The baseline social resources survey (Volume 4, Section 1.4 and Volume 4, Appendix A) identified fish (estuarine, reef and pelagic), mud crabs, reef macroinvertebrates, mud snails and mud clams to be important subsistence fisheries for households in the vicinity of the LSA. Fisheries resources that are less commonly consumed by local villagers are sharks, dugongs and turtles. Beche-de-mer (known more broadly sea cucumbers) is also harvested locally for commercial sale to overseas markets. Many of the species considered to be of important marine resource use were observed in the LSA. Given the variety of marine aquatic resources consumed, and no one species is essential for subsidence, species in the LSA are considered to be of common subsistence importance.

67 SMM Solomon Ltd Volume Critical Habitat Four species trigger the requirements of Criterion I of the IFC CH determinants; that is, habitat of importance to critically endangered and/or endangered species. These species are the critically endangered hawksbill turtle (Eretmochelys imbricata) and mangrove Bruguiera hainesii, the endangered green turtle (Chelonia mydas) and humphead wrasse (Cheilinus undulatus); all four of which were recorded in the marine ecology LSA. Currently, there is not sufficient information about the distribution of these taxa throughout Santa Isabel Island, or Solomon Islands, to make an informed decision about the extent of their occurrence, or area of occupancy. Regardless, a precautionary approach has been adopted, and, for this assessment, all mangrove communities and coral reefs within the LSA and RSA are assumed to be CH for these taxa. It is possible that other species collected and recorded, particularly invertebrates may trigger CH requirements; however, current taxonomic limitations mean it was not possible to assign undetermined taxa this status yet. Similarly, the potential for other vertebrate species to trigger CH should not be ruled out. Consequently, a more detailed and comprehensive assessment of CH will be undertaken as a supplement to this ESIA. The following conclusions can be drawn from this preliminary assessment of CH for the terrestrial ecology SoC: all mangrove communities within the LSA and RSA are assumed to be CH for Bruguiera hainesii all coral reef within the LSA and RSA are assumed to be hawksbill turtles (Eretmochelys imbricata), green turtles (Chelonia mydas) and humphead wrasse (Cheilinus undulates) additional field studies are required to assess the distribution of these species in the LSA and RSA

68 SMM Solomon Ltd. 5-1 Volume LINKAGE ANALYSIS Linkage analysis is used as a tool to illustrate the analytical approach in the impact assessment. Linkage analysis and associated linkage diagrams show how Project interactions (activities) could lead to environmental change and effects on ecology. Linkage diagrams indicate inter-relationships between other environmental and social components. Linkage diagrams comprise four symbols including ovals (Project activities), rectangles (environmental change), diamonds (key questions) and triangles (connection with other components). Linkages between Project activities and potential effects are evaluated after considering mitigation options. Potential linkages are screened to determine whether they are valid or invalid based on scientific knowledge, logic, and experience with similar developments and environmental design features. If the evaluation indicates that a potential effect is measureable then the linkage is valid for the assessment, and the resulting key question under consideration is examined. Linkages that result in no measureable effects through design and mitigation are invalid and are not carried forward to the assessment. 5.1 Geology and Soils Potential pathways (linkages) between Project interactions (activities) and geology and soils were evaluated in linkage analysis. Linkages are evaluated after assumed implementation of mitigation measures. Invalid linkages are identified as a potential effect pathway that once assessed, after mitigation measures are implemented, are identified as unlikely to have an effect. Valid linkages are project effects that have potential to actually occur, and require further analysis. They are carried forward in the impact assessment (Section 6). Geology disturbance and effects outside the mine operations are considered to be unlikely. Outside of the mine excavation operations, disturbances from the Project will extend 6 m below the topsoil and upper subsoil horizons and the effect on the geology of the region is considered to be negligible. Therefore, no valid pathway linkages between local and regional geology and the Project are deemed to exist. The potential for the Project to affect soil quality and soil quantity was evaluated by considering potential direct and indirect effects as follows: direct effects from the Project activities during construction, operations, decommissioning and closure phases indirect effects as a result of changes in surface water quality and quantity The linkage diagram is presented in Figure and linkage analysis detail is presented in Table

69 SMM Solomon Ltd. 5-2 Volume 3 From Surface Water Quality To Marine Water Quality From Surface Water Quantity To Surface Water Quality CONSTRUCTION Loss of topsoil/surface soil Erosion increased Limit of regrowth of vegetation To Human and Ecological Health OPERATIONS DECOMMISSIONING Contamination of soil Hydrocarbons Heavy metals Waste Spills Ore Solid waste What is the effect of the Project on Soil Quality and Quantity? To Marine Ecology To Terrestrial Ecology CLOSURE To Air Quality To Mine Closure and Rehabilitation Figure 5.1-1: Geology and Soils Linkage Diagram

70 SMM Solomon Ltd. 5-3 Volume 3 Table 5.1-1: Geology and Soils Linkage Analysis Project Activity Project Phase Environmental Change Vegetation clearing The Project will require the removal of vegetation which has the potential for a loss of soil quantity and quality. Topsoil/subsoil exposure and disturbance Disturbance of acid sulfate soil (ASS) Infrastructure construction Waste management Facilities operation Decommissioning and Closure The Project will require the exposure of soil including stripping and stockpiling of topsoil and subsoil to be used for rehabilitation. There is the potential for a loss of soil quantity and quality. There is a potential for ASS to be disturbed which would have an effect on soil quality. Roads, camps, a jetty and surface infrastructure will be required. There is a potential loss of soil quantity and quality from these areas. Waste management including chemical and fuel spills can affect soil quality. Soil loss through activities has the potential to reduce soil quantity and quality. Traffic Uncontrolled traffic has the potential to compact soils and cause erosion. Decommissioning, remediation and rehabilitation Decommissioning and Closure Mine decommissioning and closure phases will result in a positive impact on the soil quality and environment. Linkage status (Valid/Invalid) Valid Valid Reason Vegetation clearance will be an unavoidable effect of the Project. Approximately 376 ha of vegetation will be cleared. Surface exposure and soil stripping will be an unavoidable effect of the Project. Approximately 376 ha of land will be cleared. Valid ASS avoidance will make this link invalid. However, if ASS cannot be avoided, investigations and implementation of ASS management plans will minimise the residual impacts. Valid Infrastructure will cause unavoidable effects. Approximately 37 ha are planned for infrastructure. Invalid Invalid Invalid Valid Appropriate storage, handling, maintenance of all potential pollutant materials, machinery and equipment. Implementation of waste management plan. Appropriate chemical spill response procedure in place. Development and implementation of operational protocols and decommissioning and rehabilitation processes will negate soil impacts. Implementation of a traffic management plan and protocols, erosion and sediment control and minimising operational traffic. Improvement in soil quality.

71 SMM Solomon Ltd. 5-4 Volume Valid Linkages Valid linkages for geology and soils include: vegetation clearing topsoil/subsoil exposure and disturbance ASS disturbance construction decommissioning and rehabilitation Invalid Linkages Invalid pathway linkages do not require further analysis; however, the basis for considering the linkages invalid is discussed below. Waste Management Waste management includes the handling of waste material, chemical spills and fuel spills. Operation of machinery presents risks of the accidental release of hydrocarbons and heavy metal contamination to soils following fuel and oil spills. The use of general operational chemicals also presents the potential for spills. These spills have potential effects on the quality of the soils. However, the implementation of appropriate operational procedures for chemicals and hydrocarbons for the Project makes these potential effects invalid. Such operational procedures include: appropriate storage of chemicals and hydrocarbons including of bunding and dedicated refuelling stations proactive equipment maintenance responsive spill clean-up and remediation Operational activities such as at the workers accommodation camp can generate waste requiring disposal. The potential for this to have a negative effect on soil will be negated by the implementation of appropriate waste handling protocols and procedures. Waste generation and disposal will cease following decommissioning of the Project. Therefore, this pathway linkage to soil quality is assessed as being invalid Facilities Operation Loss of soil quantity and quality can potentially occur during mine operational activities (beyond soil exposure). The potential for this to have a negative effect on soil resources will be negated by the development of operational procedures to maximise topsoil retention and minimise non-scheduled soil exposure. Risks to soil resources will cease following decommissioning of the Project. Therefore, the linkage to soil quantity and quality is assessed as being invalid. Traffic Loss of soil quantity and quality can potentially occur during mine operational activities involving traffic movement. Potential negative effects on soil resources will be negated by careful planning of traffic movement and the development of operational procedures to minimise trafficable areas and traffic frequency. Implementation of erosion and sediment control in traffic areas will further reduce loss of soil. Also risks to soil resources will cease

72 SMM Solomon Ltd. 5-5 Volume 3 following decommissioning of the Project. Therefore, the linkage to soil quantity and quality of traffic is assessed as being invalid. 5.2 Terrestrial Ecology The linkage diagram for terrestrial ecology is presented in Figure 5.2-1, and the details of the pathways analysis are presented in Table The diagram shows linkages that could affect the terrestrial ecology between Project phases and activities, environmental change, key questions and linkages to other components.

73 SMM Solomon Ltd. 5-6 Volume 3 From Cultural Heritage From Transport To Marine Ecology From Geology and Soils From Freshwater Quantity To Surface Water Quality Changes to behaviour/reproduction From Freshwater Quality What is the effect of the Project on terrestrial ecology? To Cultural Heritage From Social Resources Change in habitat connectivity To Social Resources From Air Quality Changes to habitat quality and quantity From Noise and Vibration Changes to ecosystem processes What is the effect of the Project on terrestrial species of concern? To Human and Ecological Health CONSTRUCTION To Marine Water Quality OPERATIONS To Mine Closure and Rehabilitation DECOMMISSIONING To Transport CLOSURE Figure 5.2-1: Terrestrial Ecology Linkage Diagram

74 SMM Solomon Ltd. 5-7 Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis Project Activity Project Phase Environmental Change Vegetation clearance Chemical spills Decommissioning and Closure Loss of ecosystem processes, functions and integrity, including microclimate change due to removal of intact rainforest and replacement of that forest with rehabilitated areas of different processes and functions. Loss of quality and/or quantity of habitats (including critical habitat), populations and communities. Habitat fragmentation (including critical habitat) due to project infrastructure. Loss of individuals and populations of species (including species of concern) during clearing operations for the construction and operation. Effects to movement patterns of fauna and gene flow. Effects of accidental pollution on ecosystem integrity. Pathway status (Valid/Invalid) Valid Invalid Reason, Effect Pathway and Indicators Land clearance, habitat fragmentation and edge effects will be an unavoidable effect of the Project to terrestrial ecosystems. Approximately 376 ha of vegetation will be cleared. Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Undescribed Orchid (Liparis sp.) Sago Palm (Metroxylon salomonense) Tubi (Xanthostemon melanoxylon) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Appropriate storage, handling, monitoring and maintenance of all potential pollutant materials, machinery and equipment. Implementation of waste management plan. Appropriate chemical spill response procedure in place

75 SMM Solomon Ltd. 5-8 Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Noise and vibration Artificial light Decommissioning and Closure Decommissioning and Closure Sensory disturbance (noise and vibration) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging). Sensory disturbance (light) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging). Pathway status (Valid/Invalid) Valid Valid Reason, Effect Pathway and Indicators The Project will generate noise during construction and operation. This includes noise generated by clearing machinery, vehicles, excavation machinery, blasting, generators and other machinery used in the daily operations and infrastructure areas. Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Artificial lights utilised during night-time operations may adversely affect nocturnal species, including species of amphibians, reptiles, owls and bats Effects may occur from direct glare, periodic increased illumination and temporary unexpected fluctuations (e.g., passing vehicle lights) Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest

76 SMM Solomon Ltd. 5-9 Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Dust/Air quality Overhunting due to population influx Decommissioning and Closure Decommissioning and Closure Sensory disturbance (dust and air quality) to species leading to avoidance of otherwise suitable habitat and/or disruption of normal behaviours (e.g., breeding, foraging). Alteration of habitat (including critical habitat) due to changes in air quality (including dust, elevated metals (NI, Co) in areas not normally found). Increased hunting and resource harvesting pressure due to in-migration and camp followers. Pathway status (Valid/Invalid) Valid Invalid Reason, Effect Pathway and Indicators Dusty leaves and fruit are less palatable to fauna species, and changes in plant health and/or community structure can reduce the habitat available to fauna. Dust mitigation measures and high rainfall of the area make dust unlikely to affect vegetation species Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Food will be supplied by SMM Solomon. This is unlikely to result in further land clearance for food production. The Project will develop an influx management plan. That plan will manage the influx of camp followers into the area. Education programs will also take place for environmental awareness.

77 SMM Solomon Ltd Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Introduction of invasive species, feral animals and/or exotic species Opening of gaps and clearings in the vegetation Decommissioning and Closure Decommissioning and Closure Effects of introduced species (flora and fauna) and diseases. Loss of ecosystem processes, functions and integrity, including microclimate change due to removal of intact rainforest and replacement of that forest with rehabilitated areas of different processes and functions. Loss of quality and/or quantity of habitats Pathway status (Valid/Invalid) Valid Valid Reason, Effect Pathway and Indicators Transport of construction materials, equipment and other general supplies for use in the construction and operation of the Project has the potential to introduce invasive forms of fauna and weed species. Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Undescribed Orchid (Liparis sp.) Sago Palm (Metroxylon salomonense) Tubi (Xanthostemon melanoxylon) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Land clearance within the resource area as part of mining activities will result in the opening of gaps in the forest. These gaps may have the potential of causing micro-climatic changes, and may open areas for shade-intolerant and fast-growing plant (including invasive) species to grow.

78 SMM Solomon Ltd Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Loss of soil seed bank Uncontrolled vegetation clearing due to population influx Decommissioning and Closure Decommissioning and Closure (including critical habitat), populations and communities. Pathway status (Valid/Invalid) Reason, Effect Pathway and Indicators Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Undescribed Orchid (Liparis sp.) Sago Palm (Metroxylon salomonense) Tubi (Xanthostemon melanoxylon) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Loss of soil seed banks. Invalid Soil seed banks will be stored appropriately and replaced. Loss of soil seed banks is anticipated to be negligible. Increased hunting and resource harvesting pressure due to in-migration and camp followers. Invalid Pre-allocation of areas for crops and access limitation to other areas. The people directly associated with the mining activities will be housed and accommodated for by the Project. The Project will develop an influx management plan.

79 SMM Solomon Ltd Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Soil erosion may cause permanent soil loss and damage affecting habitat quality and quantity Decommissioning and Closure Pathway status (Valid/Invalid) Reason, Effect Pathway and Indicators Effects of soil loss and sedimentation. Invalid Stabilising the soil using effective engineering design and measures. Staging clearing, construction and mining, and mining in blocks/parcels to minimise the total area to be disturbed at any one time. Progressive rehabilitation including backfilling, topsoil management, natural regeneration and/or revegetation. Use of silt and sediment traps proximal to construction and earthmoving activities to minimise sedimentation in downslope areas. Loss of fauna species due to mortality during clearing Change in water quality causing loss of habitat Decommissioning and Closure Increased interactions of fauna species with project activities (including vehicle collisions). Valid Mitigation measures in place are expected to minimise mortality during clearing to a negligible extent, however loss of individuals during clearing cannot be completely avoided. Potential direct and indirect effects to the following VCs: Russet-Tailed Thrush (Zoothera heinei) Undescribed Orchid (Liparis sp.) Sago Palm (Metroxylon salomonense) Tubi (Xanthostemon melanoxylon) Green Snail (Papustyla sp./papustyla pulcherrima) SoCs of the lowland forest Effects of soil loss and sedimentation. Invalid Appropriate erosion and sediment control measures, based on world s best practice, will be implemented for the Project

80 SMM Solomon Ltd Volume 3 Table 5.2-1: Terrestrial Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Increased need for subsistence foods (e.g., crops) increasing the land cleared Increased need for natural resources (e.g., building materials) with an additional loss of habitat and resources Decommissioning and Closure Decommissioning and Closure Increased hunting and resource harvesting pressure due to in-migration and camp followers. Increased hunting and resource harvesting pressure due to in-migration and camp followers. Pathway status (Valid/Invalid) Invalid Invalid Reason, Effect Pathway and Indicators Food will supplied by SMM Solomon. This is unlikely to result in further land clearance for food production. The Project will develop and influx management plan. Increased need for natural resources by Project staff is not expected. The Project will develop and influx management plan.

81 SMM Solomon Ltd Volume Valid Linkages Valid linkages are carried through in the assessment. These linkages could result in measureable changes that could contribute to residual effects and include: land clearance, habitat fragmentation and edge effects noise and vibration artificial light dust and air quality introduction of invasive species, feral animals and or exotic species increased vegetation gaps causing changes in micro climate Invalid Linkages Increased Hunting and Resource Harvesting The Project workforce will be restricted from hunting and collecting vegetation in the Project area. SMM Solomon will provide the necessary food for Project staff. If food is purchased by SMM Solomon from local suppliers it will be done and a sustainable fashion so as not to cause any effects to the local population. As a result of these mitigation measures this linkage is considered to be invalid. Loss of Soil Seed Banks The loss of seed banks in soil can affect the development of vegetation types and habitat leading to a change in species assemblages in the Project area. The Project will use progressive rehabilitation and direct placement of topsoil where possible. This will limit the time that soil is stockpiled which will allow the seed bank to remain viable. Soil stockpiles will be constructed and maintained following best practices to further limit the potential for seed bank loss. Based on these measures, this linkage is invalid. Soil Loss and Sedimentation Loss of soil and increased sedimentation has the potential to cause a change in species assemblages, vegetation types and habitat. The mitigation measures that will be implemented for the Project (i.e., progressive rehabilitation, silt and sediment traps, staged development, erosion and sediment control) are designed to make any changes negligible. Therefore, this linkage is invalid. 5.3 Freshwater Ecology The linkage diagram for freshwater ecology is presented in Figure 5.3-1, and the details of the pathways analysis are presented in Table The diagram shows linkages that could affect the terrestrial ecology between Project phased and activities, environmental change, key questions and linkages to other components. Project activities that have the potential to result in the environmental changes, which, in turn, could affect freshwater ecology, include: loss of aquatic habitat sedimentation and smothering of benthic habitat change in water quality change in flow regime entrainment and impingement of biota barriers to migration

82 SMM Solomon Ltd Volume 3 From Transport From Surface Water Quantity To Marine Ecology From Surface Water Quality Loss of aquatic habitat To Surface Water Quality From Social Resources Sedimentation and smothering of benthic habitat What is the effect of the Project on freshwater habitat valued components? To Cultural Heritage From Air Quality Change in water quality To Social Resources From Noise CONSTRUCTION Change in flow regime Entrainment and impingement of biota What is the effect of the Project on freshwater biological and cultural valued components? To Human and Ecological Health To Marine Water Quality OPERATIONS Barriers to migration To Mine Closure and Rehabilitation DECOMMISSIONING To Transport CLOSURE Figure 5.3-1: Freshwater Ecology Linkage Diagram

83 SMM Solomon Ltd Volume 3 Table 5.3-1: Freshwater Ecology Linkage Analysis Project Activity Project Phase Environmental Change Linkage status (Valid/Invalid) Vegetation clearing Loss of aquatic habitat Valid Loss of aquatic habitat and vegetation associated with mining, construction of roads, road crossings and other infrastructure can affect: habitat connectivity habitat quantity and quality species abundance/distribution All VCs may potentially be affected. Water runoff from roads and river crossings Runoff from vegetation clearing, stockpile areas and sediment basin discharges Chemical spills and leaks Runoff from ore stockpile area Surface water diversions Sedimentation and smothering of benthic habitat Sedimentation and smothering of benthic habitat Valid Invalid Reason Increase in fine sediment and contaminants discharged to the aquatic environment after treatment in sediment basins/pocket ponds or from untreated runoff at river crossings or roads can affect: habitat quantity and quality species abundance/distribution All VCs may potentially be affected. The Project will design and construct appropriate erosion and sediment control structures to world s best practice standards. No sediment will leave the site. Change in water quality Invalid Contaminant spills and discharges to waterways in the mine operation area, near roads and facilities, along with unshaded diversion channels can affect water quality and: habitat quantity and quality species abundance/distribution Appropriate management measures will be in place to prevent any such events from happening.

84 SMM Solomon Ltd Volume 3 Table 5.3-1: Freshwater Ecology Linkage Analysis (continued) Linkage status (Valid/Invalid) Reason Change in flow regime Invalid Increase in surface water intercepted by diversion channels (especially during heavy rainfall) and delivered to rivers and water drawdown due to water take can affect: habitat quantity and quality species abundance/distribution Appropriate management measures will be in place to prevent any such events from happening. Project Activity Project Phase Environmental Change Surface water diversions Water supply intakes Water supply intakes Entrainment and impingement of biota Invalid Abstraction of river water may result In changes in flow regime, entrainment and impingement of aquatic biota, and affect: habitat quantity and quality species abundance/distribution Appropriate management measures will be in place to prevent any such events from happening. River crossings Barriers to migration Invalid Potential barrier to migration can affect: habitat connectivity species abundance/distribution Appropriate management measures will be in place to prevent any such events from happening.

85 SMM Solomon Ltd Volume Valid Linkages The following pathways are valid, and may result in measureable changes that could contribute to residual effects on freshwater ecology VCs: loss of aquatic habitat sedimentation and smothering of benthic habitat (river crossings and road runoff) Invalid Linkages The following linkages are invalid because the potential effects will be negligible or removed through design and mitigation measures so that there will be no detectible environmental change or residual effects (Table 5.3-1). Sedimentation and Smothering of Benthic Habitat During the construction, operation, decommissioning and closure phases of the Project there is potential for sediment to be mobilised from disturbed areas where vegetation has been cleared resulting in sediment inputs to watercourses and effects on aquatic biota. Mitigation measures will be implemented to intercept surface water runoff containing sediment from Project operational areas (mining area) and facilities (e.g., ore stockpile area and buildings) by diversion channels and deliver to sediment basins for treatment prior to release. Clean water diversion channels may be constructed upstream of some mine areas to improve the efficiency of downstream sediment control by reducing the total volume of water flowing over disturbed areas and thus requiring treatment. The mining method involves progressive vegetation clearance, mining and rehabilitation as the mine location progresses across a series of mining panels. The settling of particulates in sediment basins will reduce the levels of sediment and bound constituents (e.g., organic carbon, nitrogen, phosphorus, trace elements) being discharged to the aquatic environment. The degree of sediment removal is dependent upon sediment basin settling volumes and dynamics and the particle size of sediment entering ponds. It is expected that sediment above 1 mm will settle out in the sediment basins whilst sediment less than that will by-pass through the basins and be discharged back into the environment. This value has been chosen, as it is consistent with the observed particle size distribution of sediment in the rivers and will not result in a measureable effect above existing freshwater ecological conditions. Mitigation measures to control sediment generated from mining areas and the ore stockpile area including diversion channels, pocket ponds, check dams and sediment basins will result in no increase in sediment levels in watercourses above background levels and no measureable change in aquatic habitat so the linkage is invalid Change in Water Quality Sediment basins will provide treatment of water diverted from the resource and ore stockpile areas with basin discharges ceasing when monitored parameters (e.g., TSS, ph, oil and grease and trace metals where appropriate) exceed relevant guidelines. Diversion channel margins will be planted where practicable to provide shade and reduce the potential for elevated water temperatures. Chemical spills and leaks will be mitigated through the implementation of dedicated fuelling stations, containment systems around chemical storage, proper maintenance and training. The potential discharge of contaminants associated with the Project will be managed so that there will only be minor changes in water quality (Volume 2, Section 6.3) resulting in negligible effects on biological and cultural VCs so the linkage is invalid.

86 SMM Solomon Ltd Volume Change in Flow Regime During the operation phase of the Project there will be stormwater runoff from construction areas, facilities and mining areas during periods of high precipitation. Surface water diversion channels will intercept stormwater and divert to sediment basins for treatment prior to discharge. The diversion of surface water runoff to sediment basins will result in a minor reduction in peak stream flow rates, but not overall volume, as treated water will be released back into natural watercourses. Regular peak flow events are a natural feature of rivers in the LSA due to the steep catchment topography and high precipitation rates. Peak flows can flush river systems of fine sediment settled on streambed surfaces, dislodge and flush filamentous algae downstream, and important for shaping the natural geomorphological features (i.e., through natural erosion, coarse sediment transport and habitat formation). Fine sediment smothering surfaces and excessive filamentous algal growth are undesirable in pristine river systems. Although there may be a minor reduction in peak flow rates in some watercourses due to the diversion of runoff from Project areas to sediment basins, the magnitude of the decrease will not cause a reduction in the efficiency of high flow events to flush fine sediment and algae downstream (if present) or alter natural geomorphological processes. The linkage between changes in flow regime and freshwater ecology VCs is therefore invalid. The Nuha River has been identified as a source of surface water for dust suppression, vehicle washing, staff facilities, accommodation camp and firefighting reserves. The proposed water take has the potential to cause a reduction in flow due to draw down. The predicted water demand is m 3 /s (102 m 3 /day) and compares with a minimum measured stream flow at Nuha Camp of 1.0 m 3 /s (i.e., representing 0.1%). The water take from the Nuha River will therefore have no measureable effects on flow regime and freshwater ecology VCs so the linkage is deemed invalid Entrainment and Impingement of Biota The installation of an appropriate water intake screen (<3 mm slots) will make sure that there are appropriate sweep and approach velocities (0.5 and 0.3 m/s, respectively) that will reduce the potential for entrainment and impingement of aquatic biota (e.g., migrating shrimp, prawn and fish). The water intake screen and structure will also be installed at an appropriate location on the river that will avoid, as much as practicable, areas that are commonly used by biological and cultural aquatic VCs (i.e., streambed and river margins). Implementation of these mitigation measures will mean that the linkage is invalid. Barriers to Migration River crossings including bridges and culverts will be designed and installed following best practice guidelines to allow passage for migratory biological and cultural VCs (e.g., shrimp, prawn and fish). Measures to be implemented at river crossings will maintain a continual flow of water for aquatic biota to pass through (i.e., no vertical drops) and will allow migratory species to move freely upstream and downstream. The linkage between river crossings and freshwater ecology VCs is invalid with the implementation of best practice river crossing design and construction guidelines 5.4 Marine Ecology The linkage diagram for marine ecology is presented in Figure 5.4-1, and the details of the pathways analysis are presented in Table The diagram shows linkages that could affect the marine ecology between Project phases and activities, environmental change, key questions and linkages to other components. Additional information to support the marine ecology linkage diagram is provided in Table The table also identifies where linkages between Project activities and potential environmental effects are considered valid. Where a linkage is considered to be invalid, these are also identified.

87 SMM Solomon Ltd Volume 3 From Freshwater Ecology From Groundwater From Terrestrial Ecology From Surface Water Quality From Social Resources From Noise and Vibration From Geology and Soils Noise Light Turbidity and sediment From Air Quality To Social Resources Water and sediment quality From Waste From Transport From Marine Hydrodynamics Direct habitat loss Altered hydrodynamics What is the effect of the Project on marine ecology? To Human and Ecological Health To Mine Closure and Rehabilitation From Marine Water Quality Social (fishing and litter) To Transport From Human and Ecological Health Vessel collisions with fauna CONSTRUCTION Marine pests OPERATIONS DECOMMISSIONING CLOSURE Figure 5.4-1: Marine Ecology Linkage Diagram

88 SMM Solomon Ltd Volume 3 Table 5.4-1: Marine Ecology Linkage Analysis Project Activity Non-mining earthworks Mining-related earthworks Establishment of marine infrastructure Project Phase Environmental Change Increased turbidity and sedimentation Increased turbidity and sedimentation Increased turbidity and sedimentation Marine traffic Increased turbidity and sedimentation Marine traffic Increased turbidity and sedimentation Barge and ship loading Increased turbidity and sedimentation Valid Invalid Valid Valid Invalid Valid Linkage status (Valid/Invalid) Reason Land clearing for Project infrastructure and mining will mobilise soils. This has the potential to result in increased sediment and turbidity in waterways which can lead to downstream loss/degradation of marine habitat or reduced survival of fauna. Disturbed soils along haul roads, together with runoff from haul roads, have the potential to result in increased sediment and turbidity in waterways. This can lead to downstream loss/degradation of marine habitat or reduced survival of marine fauna. The Project will design and construction appropriate erosion and sediment control structures to world s best practice standards. Mobilised soils reporting to downstream receiving waters as part of mining operations may result in increased levels of suspended sediment and sedimentation leading to loss/degradation of habitat or reduced survival of fauna. The Project will design and construction appropriate erosion and sediment control structures to world s best practice standards. of marine infrastructure (activities such as bored piling or backfilling) may generate increased turbidity and subsequent sedimentation which may lead to loss and or degradation of habitat or reduced survival of fauna. Propeller action during movement of marine vessels may resuspend sediment. Mobilised sediments from channel deepening for marine vessels (dredging, blasting and spoil disposal) could result in increased levels of suspended sediment and sedimentation leading to loss/degradation of habitat or reduced survival of fauna. The Project will implement best practice to avoid such events. Spillages of ore may result in water column turbidity and smothering of benthic habitat.

89 SMM Solomon Ltd Volume 3 Table 5.4-1: Marine Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Ore stockpiling Increased turbidity and sedimentation Establishment of marine infrastructure Marine traffic Direct loss of marine habitat Direct loss of marine habitat Marine traffic Direct loss of marine habitat Establishment of marine infrastructure Establishment of marine infrastructure Invalid Valid Invalid Valid Linkage status (Valid/Invalid) Reason Ore eroded from stockpiles reporting to the marine environment, resulting in increased levels of suspended sediment and sedimentation leading to loss/degradation of habitat or reduced survival of fauna. The Project will design and construction appropriate erosion and sediment control structures to world s best practice standards. Installation of marine infrastructure will result in direct loss of habitat directly under infrastructure. Deepening of areas used for shipping channels (if required) requires blasting and/or dredging and spoil disposal. This would result in the direct loss of marine habitats. The Project will design and construction appropriate erosion and sediment control structures to world s best practice standards. Shipping traffic may lead to seabed and shore erosion through turbulence or scour. Underwater noise Valid Generation of elevated underwater noise through bored piling activities for jetties and transhipment mooring. May lead to direct mortality or behavioural effects on fauna. Underwater noise Invalid Blasting of small patch reefs to improve navigational access would generate elevated underwater noise which may lead to direct mortality or behavioural effects on fauna. Marine traffic Underwater noise Valid Underwater noise will be generated as a result of vessel movements and has the potential to lead to behaviour modification of some marine fauna. Night lighting Light pollution Valid Use of artificial lighting on vessels, jetties and transshipment moorings at night can interfere with the behaviour of some marine animals. This can influence reproduction or survival of individuals.

90 SMM Solomon Ltd Volume 3 Table 5.4-1: Marine Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Marine traffic Introduced marine pests Decommissioning and Closure Presence of marine infrastructure Chemical and hydrocarbon storage Chemical and hydrocarbon storage Decommissioning and Closure Decommissioning and Closure Altered marine hydrodynamic conditions Contamination of water and sediments Contamination of water and sediments Earthworks Contamination of water and sediments Earthworks Earthworks for the establishment of marine infrastructure Contamination of water and sediments Contamination of water and sediments Valid Invalid Valid Invalid Valid Valid Invalid Linkage status (Valid/Invalid) Reason Marine pests could be introduced to the area through ballast water or attached to the hulls of vessels, resulting in habitat degradation and displacement of native species. Installation of jetties could alter marine hydrodynamic conditions resulting in changes to shorelines. Accidental release of chemicals and/or hydrocarbons into, or near waterways during refuelling of vessels could result in loss/degradation of habitat or reduced survival of fauna. Accidental release of stored chemicals and/or hydrocarbons into, or near waterways or groundwater could result in loss/degradation of habitat or reduced survival of fauna. The Project will employ best practice management to avoid these events. Disturbance of soils could generate elevated concentrations of dissolved metal, which could report to marine waters and result in adverse effects on aquatic biota. Metals associated with disturbed mineralised materials may report to downstream receiving waters resulting in adverse effects on aquatic biota. Disturbance of soils could oxidise sulfidic material generating acid and elevated concentrations of dissolved metal, which could report to marine waters and result in adverse effects on aquatic biota. The Project will employ best practice management to prevent this from occurring.

91 SMM Solomon Ltd Volume 3 Table 5.4-1: Marine Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Ore stockpiling Contamination of water and sediments Waste water discharge Barge and ship loading Barge and ship loading Marine traffic Social Social Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Decommissioning and Closure Contamination of water and sediments Contamination of water and sediments Contamination of water and sediments Collisions with marine mammals and reptiles Increased fishing pressure Increased fishing pressure Valid Invalid Valid Invalid Valid Invalid Valid Linkage status (Valid/Invalid) Reason Particulate and dissolved metals washed from ore stockpiles has the potential to contaminate marine waters and bed sediment, with concomitant toxicological impacts on biota. Waste water discharges from the accommodation camp could lead to increased levels of pathogens, nutrients and chemicals which could result in contamination of sediments, nuisance algal growth, degradation of habitats and reduced survival capability of fauna. The Project will employ best practice management to prevent this from occurring. Spillage of ore may result in contamination of water column and bed sediment, with concomitant toxicological impacts on biota Washing out of barge holds may result in contamination of water column and bed sediment, with concomitant toxicological impacts on biota. The Project will employ best practice management to prevent this from occurring. Collisions of vessels with marine mammals and reptiles could occur as a result of shipping traffic, leading to injury or death of individuals. An increase in the number of people harvesting marine resources due to fishing activities by the workforce can lead to local depletion of some marine species. The Project will employ best practice management to prevent this from occurring. An increase in the number of people harvesting marine resources due to local communities supplying food for the workforce can lead to local depletion of some marine species.

92 SMM Solomon Ltd Volume 3 Table 5.4-1: Marine Ecology Linkage Analysis (continued) Project Activity Project Phase Environmental Change Social Decommissioning and Closure Linkage status (Valid/Invalid) Reason Litter Valid An increase in the number of people littering may result in increased litter in the marine environment leading to reduced survival of some marine animals.

93 SMM Solomon Ltd Volume Valid Linkages The following pathways are valid, and may result in measureable changes that could contribute to residual effects on marine ecology VCs: Increased turbidity and sediment due to the following activities: earthworks in construction phase due to land clearing for infrastructure and mining earthworks in operational phase due to disturbed soils along haul roads establishment of marine infrastructure such as jetties and the transhipment mooring marine traffic in the shipping channels barge and ship loading at the jetties and transhipment mooring Direct loss of marine habitat due to the following activities: establishment of marine infrastructure such as the laydown area, ore stockpile, jetties, transhipment mooring and haul road marine traffic in the shipping channels Underwater noise due to the following activities: establishment of marine infrastructure such as jetties and the transhipment mooring vessel movements Light pollution due to night lighting from the jetties, transhipment mooring and vessels. introduced marine pests in ballast water or attached to the hulls of vessels Contamination of water and sediment due to the following activities: accidental spillage of fuel during refuelling of marine vessels metals mobilised from mine materials, potentially including soil, overburden and ore at the mine site, ore stockpiles and ore spilled during barge and ship loading Collisions with marine mammals and reptiles due to increased marine traffic from vessels. Increased fishing pressure due to local communities supplying food for the workforce: an increase in litter from the workforce Invalid Linkages Invalid linkages are identified in Table The rationale for each invalid linkage is provided below. Mitigation measures relevant to these issues are described in Table Increased Turbidity and Sedimentation Earthworks during Mining Mining will require land clearing which will result in mobilisation of soils from disturbed areas. Effects of mobilised soils from the mining area will extend throughout the entire period of operations with progressive rehabilitation of mined areas undertaken to mitigate these effects.

94 SMM Solomon Ltd Volume 3 Increased turbidity and sedimentation associated with earthworks during mining operations is considered to be an invalid linkage due to the proposed erosion and sediment control systems for the mine. The systems will be designed to maintain the concentrations, frequency and duration of sediment inputs such that they are consistent with the natural turbidity and sedimentation regime. Ore Stockpiling During operations, limonite and saprolite ore will be delivered separately to the export ore stockpile and stored in long windrows. The moisture of the delivered ore is expected to be 38% for limonite and 35% for saprolite, however, to meet international shipping requirements the moisture content must be reduced to 35% and 30%, respectively. This requires a drying period to allow both drainage and air drying. The windrows will allow central access so piles can be turned by a front end loader. Tarpaulins will be used to cover some of the ore stockpile and enhance run-off of rain. Material washed from the ore stockpiles has the potential to report to the marine environment, resulting in increased levels of suspended sediment and sedimentation. However, the mitigation measures include a series of drainage controls that will be designed to capture and retain mobilised ore to prevent input into receiving waters. The water retained in the drainage controls will be tested prior to release to make sure it is suitable quality for release to the environment. Release of the water will occur over a large, flat vegetated area to encourage further filtration through the soil before the water meets groundwater. Silt fences/curtains will also be installed to restrict particulates in runoff from entering marine waters, where necessary Channel Deepening for Marine Vessels Removal of the seabed to provide sufficient depth for vessel movements, if required as part of construction activities, will mobilise sediment in the water column during dredging, blasting and spoil disposal. The transhipment mooring location is located in water depths greater than 20 m and dredging is not required for vessels to access this point. The natural access channel for ocean going vessels, located between Tanabrahu Reef and Belamana Reef approximately 1 km south southwest of the transhipment mooring location, is approximately 850 m wide. Water depth in the passage varies from 20 to 70 m. Deepening of channels is also not required for ore transfer barges to access the jetty landing area or boats to provide personnel transfers. Based on the current Project description, dredging or blasting to provide vessel access is not necessary. As such, increased turbidity and sedimentation, and also direct loss of habitat and elevated underwater noise, from channel deepening activities are considered to be invalid linkages Altered Marine Hydrodynamics Marine infrastructure to support the Project will include a passenger ferry jetty (probably consisting up to 12 piles) suitable for small boats to moor, a supplies jetty and an ore loading jetty (consisting of approximately four large piles each). The presence of marine infrastructure has the potential to affect local marine hydrodynamic conditions. Installation of near shore marine infrastructure could alter marine hydrodynamic conditions including modification in tidal flushing, wave and current regime, sediment erosion and accretion. These changes may also subsequently impact water and sediment quality, and the availability of habitat especially if large amounts of erosion occur or if sediment smothers corals and seagrass.

95 SMM Solomon Ltd Volume 3 Marine hydrodynamic investigations undertaken in the area (Volume 2, Appendix E) indicate that there is limited net movement of water in the area of the passenger ferry jetty and that currents are driven by tides. This would also be expected to be the case in the more protected embayment where the ore loading jetty will be located. Given the limited amount of marine infrastructure and the limited water movement in the area of the structures, there is expected to be a negligible effect on marine hydrodynamics. Therefore, this linkage is considered to be invalid Contamination of Water and Sediment Accidental Release of Chemicals/Hydrocarbons during Handling and Storage Spillages of fuels, oils and other hazardous substances (e.g., hydraulic fluids, solvents and paints) from land facilities during handling or storage may cause contamination of marine waters. However, the mitigation measures designed to prevent, contain and respond to any such events from land facilities, it is considered that there is no linkage for effects to occur on marine flora or fauna. Accidental spillage of fuels during refuelling of marine vessels is considered a valid linkage and is further assessed. The worst case scenario for an accidental spill would the event of a vessel collision or grounding on a reef resulting in the spillage of a large quantity of fuel. Such an event should be prevented by successful implementation of a marine traffic management plan and, as such, is considered to be an upset event addressed through risk management. Disturbance of Acid Sulfate Soil during Earthworks Earthworks may disturb naturally occurring ASS resulting in oxidation of sulfidic material, thereby generating sulfuric acid and elevated concentrations of dissolved metals. These contaminants may report to marine waters and result in adverse effects on aquatic biota. Acid sulfate soils commonly occur on coastal wetlands as layers of Holocene marine muds and sands deposited in protected low-energy environments, such as estuaries and coastal lakes. Soil disturbance due to earthworks will occur near the marine environment in the area of the ore stockpile, laydown area, accommodations camp, jetties and access roads. These activities will occur during the construction phase. The Geology and Soils Baseline Report (Appendix A) identified soils in Project infrastructure areas on the coastline to be comprised of limonitic soils or carbonate sands generated from the fringing reefs and therefore considered the risk of ASS to the environment to be low. Accordingly, the risk of adverse effects to marine aquatic biota due to ASS is considered to be negligible, particularly given the natural buffering capacity of seawater which will neutralise any acid generated. Sampling for ASS analyses will be undertaken in any areas of swamp or mangrove muds that will be disturbed during the construction of infrastructure and liming of soils undertaken, if required. Given the negligible risk and the proposed mitigation measures in any areas of swamp or mangrove muds that will be disturbed, the linkage for ASS to effect on marine flora and fauna is considered to be invalid. Wastewater Discharges from Accommodation Camp A camp to accommodate up to about 150 people will be located near the ore stockpile area. Wastewater discharges (sewage and grey water) from the camp could lead to increased levels of pathogens, nutrients and other chemicals which could result in contamination of sediments, nuisance algal growth, degradation of habitats and reduced survival capability of fauna.

96 SMM Solomon Ltd Volume 3 Wastewater will be treated in a sewage treatment plant with effluent discharges managed in accordance with World Bank environmental, health and safety guidelines for wastewater and ambient water quality (IFC 2007) (such as reuse of wastewater for irrigation at the camp and disposal of sludge at a landfill site). The risk to the marine environment due to wastewater discharges from the camp is therefore considered to be negligible and the linkage to effects on marine flora and fauna is considered to be invalid. Water Discharges from Washing of Barge Holds Cleaning of barge holds into the marine environment may lead to effects associated with increased turbidity and sediment and contamination of water and sediment. Mitigation measures employed for barge hold cleaning during the Project will prevent water from cleaning operations being discharged into the marine environment. As such, this linkage is considered to be invalid Increased Fishing Pressure due to Workforce The presence of the workforce required for the Project may increase pressure on local fisheries resources, particularly in areas close to the camp, if workers are permitted to harvest marine resources. This could lead to a decline of subsistence and commercially important fisheries species in the area, which in turn could affect the structure of marine communities, as well as affecting the livelihoods of the local fisherman. As the workforce will be banned from fishing or taking marine resources in the area, the effects of such increased fishing pressure is considered to be an invalid linkage. However, the linkage does exist that local fishermen may increase fishing effort to provide food for the workforce and this is assessed.

97 SMM Solomon Ltd. 6-1 Volume IMPACT ASSESSMENT This section presents the assessment of the residual effects that the Project may have on the geology and soils, terrestrial ecology, freshwater ecology and marine ecology. The effects are assessed based on the assumption that all mitigation measures have been successfully implemented. 6.1 Geology and Soils The impact assessment considers the potential effects of the Project on soils in the LSA in the context of the valid linkages. Existing soil conditions are described in the Geology and Soils Baseline Report (Appendix A) and summarised in Section 4.1. Potential direct and indirect effects on soil quantity and soil quality resulting from the Project activities with valid pathway linkages are assessed in this section What is the Effect of the Project on Soil Quantity? Effects Assessment The potential for the Project to affect soil quantity was evaluated based on potential pathway linkages of vegetation clearing, surface disturbance of soils and infrastructure construction. The vegetation clearing and surface disturbance (topsoil and subsoil exposure) are considered together. The soils in the LSA will be disturbed by vegetation clearing, soil exposure and disturbance by infrastructure development during the construction, operation and decommissioning of the Project. Most of the potential for disturbed soil will be in the mining area and in areas of the infrastructure, including the accommodation camp, other buildings and transport routes. Approximately 376 ha of land will be cleared and disturbed. This disturbance area represents about 3.1% of the LSA (12,310 ha) and less than 0.1% of Santa Isabel Island. The greatest effect of soil disturbance is the loss of surface soils through erosion Impact Classification There is the potential for the clearing of vegetation and construction of infrastructure to increase the risk of erosion. The effect of the loss of soil due to erosion is negative, as it may affect the rehabilitation of vegetation following mine closure. The magnitude is low as the area of effect is less than 10%. The effects will be limited to the LSA (local extent) and will remain for the life of the Project (medium term duration). The exposure of soils following clearing activities will be continuous until remediated and so the frequency is considered to be high. Following decommissioning and closure of the Project, exposed areas of soil are expected to be fully rehabilitated by revegetation. This limits the risk of additional soil loss and allows the eventual redevelopment of a soil profile similar to baseline conditions. Based on this, the effects on soil loss of the Project are considered to be reversible. Based on the above, the predicted residual impact rating is low (Table 6.1-1).

98 SMM Solomon Ltd. 6-2 Volume 3 Table 6.1-1: Residual Impact on Soil Quantity and Quality Potential Effect Direction Magnitude Geographic Extent Duration Frequency Reversibility Impact Level Soil Quantity Soil loss due to clearing Soil Quality Soil loss due to clearing Disturbance of ASS Equipment removal, remediation & rehabilitation Negative Low Local Medium High Reversible Low Negative Low Local Medium High Reversible Low Negative Negligible Regional Short Negligible Reversible Negligible Positive Low Local Far Future High n/a Low What is the Effect of the Project on Soil Quality? Effects Assessment The potential for the Project to affect soil quality was evaluated based on potential linkage pathways of: vegetation clearing surface disturbance of soils infrastructure construction acid sulfate soils removal of equipment, site remediation and rehabilitation The vegetation clearing and surface disturbance (topsoil and subsoil exposure) are considered together. Vegetation clearing, topsoil/subsoil exposure and disturbance, and infrastructure construction The soil quality in the LSA, as well as the soil quantity, will be disturbed by vegetation clearing, soil exposure and disturbance by infrastructure development during the construction, operation and decommissioning of the Project. The greatest effect of soil disturbance is the loss of surface soils through erosion. The potential area affected and the attributes are discussed in Section Acid Sulfate Soils (ASS) The coastal areas where ASS may occur in the LSA are restricted to low-energy, mangrove environments. The coastal infrastructure areas are generally characterised by limonitic soil likely generated from the fringing reefs in these areas and, therefore, not ASS. Avoidance of ASS disturbance is anticipated and, therefore, the link with ASS is likely to be invalid.

99 SMM Solomon Ltd. 6-3 Volume 3 However, the Project includes the clearing of areas of mangroves (1 ha or <0.1% of the LSA). Therefore, the potential effect of disturbing actual ASS (AASS) and potential ASS (PASS) in these areas includes the generation of, or increase in, soil acidity. An increase in soil acidity may affect freshwater and marine water quality, which has the potential to affect freshwater and marine ecological communities. Effects from ASS disturbance are considered to be negative. The magnitude is negligible as the area of effect is less than 1%. The effect is likely to be limited to the areas immediately surrounding the disturbance, although marine communities in adjacent coastal waters could be affected as acidity travels offshore (local to regional extent). The disturbance of ASS should be limited to the construction activities, therefore the duration is considered to be short and the frequency is low. Should likely ASS be encountered and marked for disturbance, an ASS investigation will be carried out prior to that disturbance. Given appropriate mitigation and that management of disturbed ASS has the capacity to neutralise any ASS generated acidity, the residual effect should be reversible; however, given the possibility of a regional impact, the residual effect is considered to be negligible. Removal of Equipment, Site Remediation and Rehabilitation The decommissioning and closure phases, which includes the removal of equipment and infrastructure, site remediation and rehabilitation, will have a positive effect. Remediation and rehabilitation actions include: sites of spills and wastes will be investigated and, if required, remediated and validated reinstatement and amelioration (where required) of topsoil over disturbed areas ready for revegetation will improve soil quality The (positive) magnitude of these activities is considered low and the benefits will have local (LSA) and regional effects. Benefits will be far into the future after the closure of the mine and operations, and will be continuous, so the frequency of the benefits is considered to be high. The residual effect is assessed as being low and positive Impact Classification The residual impact to soil quality from vegetation clearing in the LSA is considered to be low Table Prediction of Confidence The geology and soils landscape of Santa Isabel Island is reasonably well understood based on the historical geological survey and mining data. Based on this prior knowledge and understanding, as well as a good understanding of how limonitic and other soils behave (from studies in similar environments), the confidence in the presented assessment is high. 6.2 Terrestrial Ecology What is the Effect of the Project on Terrestrial Ecology? Effects Assessment A number of Project interactions were identified as potentially having an effect on the terrestrial ecology of the area. These include: land clearance, habitat fragmentation and edge effects direct mortality caused by clearing

100 SMM Solomon Ltd. 6-4 Volume 3 noise and vibration artificial light dust and air quality introduction of invasive species, feral animals and or exotic species increased vegetation gaps causing changes in micro climate Land Clearing, Habitat Fragmentation and Edge Effects Land clearance resulting in direct loss of habitat, habitat fragmentation and edge effects will be an effect of the Project. Approximately 376 ha of vegetation will be cleared. A direct result of clearing is habitat fragmentation, the process by which contiguous habitats become divided into fragments that are isolated from each other by development or otherwise non-forest habitat (Lindenmayer and Fischer 2006). The ecological effects of habitat fragmentation potentially include: reduction in the total area of the habitat increase in the relative amount of edge (i.e., non-forested areas surrounding a forest patch) decrease in the amount of interior habitat (refers to remaining forested areas not affected by edge affects) isolation of one habitat fragment (including populations) from other areas of habitat decrease in the average size of each patch of habitat Habitat loss will reduce the total habitat area available for species and may lead to crowding and increased competition among individuals and species, as mobile animals (especially birds and mammals) retreat into remaining remnant patches of habitat (Lindenmayer and Fischer 2006). Species that require large areas of interior habitat may slowly decrease in population size if they are unable to move between forest fragments when there is an increase in the area of edge effect and decrease in amount of interior habitat. Habitat fragmentation and vegetation clearing may also lead to edge effects. This refers to effects that occur at the interface between natural habitats (particularly forests) and disturbed or developed land (Yahner 1988). Once an edge is created between forest and a cleared area, changes to ecological processes can extend between 10 m and 100 m from the edge (Yahner 1988). These include microclimatic changes in light, temperature, humidity and wind, which can favour a suite of different species and therefore cause changes to the ecology of the patch (Lindenmayer and Fischer 2006). Predation too, often increases at the edge of cleared areas as these areas are more accessible to predators and provide less shelter/cover for prey. Increased predation pressure may lead to a continuous decline in the prey population, affecting the local food web. The anticipated disturbance area resulting from the Project s development represents about 6.2% (376 ha) of the LSA (6,010 ha), or 2.0% of the RSA (18,900 ha) and less than 0.1% of Santa Isabel Island (2,999 km 2 ) (Table 6.2-1). The vegetation to be cleared is predominately lowland forest (371 ha), with approximately 4 ha of freshwater wetlands and 1 ha of coastal strand vegetation also to be removed to make way for Project infrastructure. Once ore

101 SMM Solomon Ltd. 6-5 Volume 3 extraction is completed, all areas cleared for the Project will undergo rehabilitation and revegetation with plant species native to the local area. Table 6.2-1: Clearing Vegetation Types Vegetation Type Total Area LSA [ha] Proposed Cleared Area LSA [ha] Percentage Clearing LSA [%] Lowland Forest 4, Freshwater Swamp Coastal Vegetation (Mangroves) Total Area 6, For the purposes of the impact assessment, it is assumed that all vegetation shall be cleared simultaneously at the beginning of the Project and shall remain cleared for the entire duration of the Project (the maximum disturbance footprint). However, this will not be the case because vegetation clearing shall be staged, and progressive rehabilitation of areas will occur as soon as practical on all cleared areas. Therefore, the effects to the ecology of the area will be transient over the life of the Project, which is 14 years. It is expected that rehabilitation and revegetation of the mined areas will, eventually, return the forest communities to a state resembling current conditions. Direct mortality caused by clearing Vegetation clearing activities will be undertaken during the construction phase of the Project. Highly mobile species (e.g., birds and bats) are likely to initially move away from affected areas. Animals that are relatively immobile or have limited dispersal abilities (e.g., amphibians, some reptiles, young individuals, and invertebrates) may have difficulty escaping and may be subject to direct mortality or injury. To limit the effect of direct mortality on species from clearing, all areas shall be searched prior to clearing and all species found within the area relocated to an appropriate area. Plant SoC will be collected as nursery specimens, or relocated, if feasible. The Project will clear about 6.2% of the LSA (Table 6.2-1). With the appropriate management measures in place, that is relocation of individuals from cleared areas, the effect of direct mortality is expected to be low. Noise and Vibration The Project will generate noise during construction and operation. This includes noise generated by machinery, vehicles, excavation machinery, and generators. That noise is likely to affect a wide range of species and the VCs. Areas of noise creation may be avoided by mobile animals; this may lead to a reduction in suitable habitat for certain species as they avoid these otherwise suitable habitats. Noise produced by human activities can affect an animal's physiology and behaviour. If noise becomes a chronic stress, it can be detrimental to an animal's energy budget, reproductive success and long-term survival. Noise also affects the way that animal-created sounds are heard and interpreted by other animals, including mating calls, territorial calls and alarm calls. Interference with these calls can lead to reduced reproductive success and/or mortality. Species responses to noise disturbances cannot be generalised across species or among genera, and there may even be response differences among different populations of the same species (Larkin et. el. 1996).

102 SMM Solomon Ltd. 6-6 Volume 3 The baseline noise environment (Volume 5, Appendix B) within the LSA is characterised by background levels of above 50 decibels (db). These levels are naturally present during dawn and dusk choruses (Volume 5, Appendix B). Noise modelling indicates that noise levels above the ambient 50 db will be restricted to those areas immediately surrounding the Project footprint, with the noise levels dissipating rapidly from the boundary of the Project footprint. More precisely, the modelling indicated a total area of 629 hectares will be affected by noise levels greater than 50 db, or 10% of the LSA. However, 139 ha (or 2% of the area) will be within the direct mine footprint, and hence cleared of habitat for potentially noisesensitive species. It is expected that only 8% of habitat in the LSA will be affected by noise levels above existing background levels. Artificial Light The construction and operation phases of the Project will require various intensities and frequencies of artificial lighting, which can reduce habitat quality for many species, and interrupt or alter natural behaviours. Light associated with Project activities has the potential to adversely affect survival and behaviour of terrestrial animal species, including insects, frogs, reptiles, birds and bats, potentially resulting in biodiversity loss. For example, artificial lights utilised during night-time operations may adversely affect nocturnal species, including species of amphibians, reptiles, owls and bats. The effects may result from direct glare, periodic increased illumination and temporary unexpected fluctuations (e.g., passing vehicle lights) (Longcore and Rich 2004). Light pollution can also trigger behavioural and physiological responses in fauna, including: an extension of diurnal or crepuscular foraging behaviour into the night-time, behaviour that is not normal and may be detrimental to the individuals in the long-term, or may put pressure on populations of food items a disruption of seasonal day length cues, which trigger critical behaviours (Longcore and Rich 2004) temporary blindness and disorientation (sometimes lasting hours) a disruption to predator-prey relationships These responses may lead to changes in breeding and forage patterns, which can lead to population declines and even permanent injury or death. Areas affected by artificial light in the LSA, following mitigation measures, are expected to be within cleared areas and within a 25 m buffer surrounding the mining area and accommodation camp. Effects of lights on the haul road are expected to be intermittent due to passing vehicles. Dust and Air Quality During construction and operations, all Project activities that create air emissions and dust have the potential to interact with the terrestrial ecology. Air emissions and dust sources include construction activities (e.g., site clearing, land preparation, topsoil stripping), mining (e.g., excavation, stockpiling and blasting), ore crushing, ore processing, ore loading and transportation. and mining activities will generate fugitive dust that can accumulate on leaf surfaces, inhibiting photosynthesis, respiration and transpiration processes. Dust may also cause blockage and damage to stomata, shading and abrasion of leaf surfaces or cuticles. Stressed plants are more susceptible to pathogens and other disturbance, and are more likely to be subject to increased mortality; decreased productivity, and changes in community structure may then result (Farmer 1993).

103 SMM Solomon Ltd. 6-7 Volume 3 Poor plant health also affects fauna species that depend on them either, as a source of food and/or habitat. Dusty leaves and fruit are less palatable to fauna species and changes in plant health and/or community structure can reduce the habitat available to fauna. However, due to the high rainfall in the Project Area, the intensity of effects, due to fugitive dust, is likely to be low. Introduction of Invasive Species, Feral Animals or Exotic Species The introduction of invasive, feral and exotic species may potentially affect the terrestrial ecology of the area by outcompeting native species for space, light, nutrients and water. Some invasive species trend to spread easily, and may be problematic and expensive to eradicate. Invasive flora species predominantly establish in disturbed (cleared) areas prior to seed dispersal into surrounding areas. Introduced species may affect the terrestrial ecology within, and outside, the LSA and RSA. Following mitigation measures, an assessment of the potential areas affected by invasive species over the life of the Project was undertaken for cleared (disturbed) areas, and areas of increased edge effects expected to be affected by invasive species. Proposed mitigation measures outline the control of invasive species throughout the Project Area and identification and recording of new invasive species within disturbed areas. These control measures are expected to minimise the effects of invasive species to the Project Area. Increased Vegetation Gaps The construction and operation phases of the Project will involve the clearance and disturbance of different portions of land. Land clearance in the resource area, as part of mining activities, will result in the opening of gaps in the forest. These gaps may have the potential of causing micro-climatic changes, and may open areas for shade-intolerant and fast-growing plant species (including invasive species) to grow. Increased vegetation gaps creates changes in solar radiation, ambient moisture levels, air temperature and soil moisture levels creating environmental changes which can affect the environmental conditions and resource availability of species (Canham and Marks 1985). This change in environmental conditions may result in modified habitat, consisting of a change in species diversity and populations. This effect is very likely for the Project, and, consequently may detrimentally affect the local ecology Impact Classification The direction of the vegetation clearing is identified as negative because species populations and available habitat shall be potentially lost. The magnitude of the clearing is considered low because less than 10% of any one of the vegetation types (habitats) in the LSA will be cleared. The surrounding area in the RSA contains these vegetation types with little disturbance. A total of 6.2% of the LSA will be cleared during the Project (Table 6.2-1), consisting of 8.1% of lowland forest, 0.4% freshwater swamp and 0.1% coastal strand vegetation (mangroves). Consequently, the geographical extent of the clearing is quite limited, and, as such is limited to the local area. Vegetation clearing and habitat fragmentation will persist in the long-term, that is, during the construction, operation, and decommissioning phases, and for some years beyond. The frequency is considered negligible as vegetation will only be created once, but is reversible via rehabilitation. Based on the above, the impact rating the vegetation clearance and habitat fragmentation on terrestrial ecology and terrestrial species of concern is expected to be low (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from vegetation clearance are moderate (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species.

104 SMM Solomon Ltd. 6-8 Volume 3 Individuals will be lost through direct mortality from vegetation clearing; this is a negative direction (Table 6.2-2). The magnitude of species loss, however, is considered low because it is anticipated that less than 10% of species within the LSA may be lost and, while individuals are expected to be lost, the effects will not remove an entire population from within the LSA. Importantly, animals will be relocated, and plant SoC will be translocated, or used as nursery specimens. From an aerial extent perspective, and taking area cleared as a surrogate for number of species, the maximum cleared area is only 6.2% of the LSA. Therefore, it can be interpolated that ~6% of the population of plants within the area will be removed and lost through clearing. Direct mortality will be localised and restricted to the Project footprint. The surrounding habitat that will not be cleared, and it is expected to support sustainable populations of all species such that there will be no long-term effects on populations. The duration is short term (less than one year) as the clearing is expected to occur during the construction phase. The frequency is considered negligible as the activity (clearing) only occurs once. However, the effects of direct mortality are irreversible. It is expected, that the population loss, certainly for many species, will be reversed as the rehabilitation of the area progresses, which may allow for a return to the original population of species. Based on the above, the residual impact level of direct mortalities caused by clearing on terrestrial ecology and terrestrial SoC is expected to be negligible. The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from direct mortality from clearing is negligible (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species. The effects of noise on the terrestrial ecology of the LSA are considered negative because generated noise may reduce habitat quality and affect behaviour of species. The magnitude of the area of habitat affected by noise emissions and vibration is considered low, because less than 10% (~490 ha) of the LSA is expected to be effected by increased noise levels of greater than 10% of the ambient (50 db). Geographically, noise and vibration effects are expected to be limited to the LSA and considered local. The duration of the noise effects will last through the Project s operations, and hence is medium term. The frequency of noise and vibration is considered moderate because noise effects are expected to occur more than once per day, but may not be continuous, and all are reversible. Based on the above, the impact level for noise and vibration effects is considered low (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from noise and vibration is moderate (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species. The effect of light on the terrestrial ecology of the LSA is considered negative because light may reduce habitat quality, and/or alter normal behaviours. The magnitude of the effects from light are considered low because the area of habitat affected by light emissions is considered low less than 10% of the LSA (Table 6.2-1). Geographically, light effects are expected to be limited to within the LSA, and considered local. The duration of the light effects is medium term (less than 14 years) during the construction and operational phase. Artificial lights will be activated for most of the night-time hours during construction, operation and decommissioning, this results in a moderate frequency. The effect of light is reversible, with the removal of the source. Therefore, based on the above, residual impact level of artificial light on terrestrial ecology and terrestrial species of concern is expected to be low (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from light is moderate (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species. Dust and air quality associated with the Project has a potential to reduce habitat quality and is considered negative (Table 6.2-2).

105 SMM Solomon Ltd. 6-9 Volume 3 The effects of dust and air emissions on terrestrial ecology are expected to be negative. The magnitude of air emissions and dust, after mitigation, is expected to be low as less than 10% of species populations and habitat within the LSA may be affected based in the extent of sources of dust. The effects are considered local within the LSA and occur only during the construction and operation phases, that is, in the medium term (less than 14 years). The frequency is expected to be limited number of times per day, a moderate frequency. Therefore, based on the above, effects to terrestrial ecology from dust and air emissions from the Project are expected to have a low residual impact level (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from noise and air emissions is moderate (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species Dust and air quality associated with the Project has a potential to reduce habitat quality and is considered negative (Table 6.2-2). Effects associated with invasive species on the terrestrial ecology are considered negative. The potential magnitude of invasive species being introduced and spread is considered low, provided mitigation measures are effective and limit any areas affected by invasive species to less than 10% of the Project Area. If any invasive species are introduced, there is a high potential for them to spread, and the effect is likely to extend beyond the LSA into the RSA. The eradication may potentially be a long term process. The frequency is considered negligible, because an invasive species may only need to be introduced once to cause an effect and is considered reversible through the eradication of the species. Based on the above the residual impact level for invasive species is low (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from invasive species is moderate (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and rangerestricted species (Table 2.6-1). Effects to terrestrial ecology associated with increased gaps are negative. However, effects are only expected to cover less than 10% of the LSA. The geographical extent of effects will be limited to the LSA, and are considered low. The duration is long term because the gaps will exist beyond the life of the Project, until the revegetated areas reach full maturity. The frequency is considered negligible because the vegetation gaps are created once. The effects are reversible through rehabilitation. Based on the above, the residual impact level from gaps in vegetation on terrestrial ecology is negligable (Table 6.2-2). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects from gaps in vegetation is negligable (Table 6.2-2). This is due to the lowland forest community supporting populations of species new to science, and the potential for endemic and range-restricted species (Table 2.6-1).

106 SMM Solomon Ltd Volume 3 Table 6.2-2: Residual Impact on Terrestrial Ecology Project Activity Indicator Direction Magnitude Geographic Extent Duration Frequency Reversibility Effect Level Sensitivity Overall Impact Land clearance, habitat fragmentation and edge effects Direct mortality caused by clearing Noise and vibration Artificial light Dust and air quality Introduction of invasive species, feral animals and or exotic species Increased vegetation gaps causing changes in micro climate Species population Available habitat after clearing Species Population Species population Available habitat Species population Available habitat Species population Available habitat Invasive species populations Health and status of native populations Species population, available habitat after clearing Invasive species populations Negative Low Local Medium Negligible Reversible Low High Moderate Negative Low Local Short Low Irreversible Negligible High Negligible Term Negative Low Local Medium Moderate Reversible Low High Moderate Negative Low Local Medium Moderate Reversible Low High Moderate Negative Low Local Medium Moderate Reversible Low High Moderate Negative Low Regional Medium Negligible Reversible Low High Moderate Negative Low Local Long Term Negligible Reversible Negligible High Negligible

107 SMM Solomon Ltd Volume Prediction of Confidence The time frames, Project sites and locations of potential effects are well identified. However, there is uncertainty associated with the consequences that an increased human presence may generate, which include land disturbance, overhunting and sensory disturbances (i.e., noise, vibrations, light and odour). Given that data has been collected and handled by experienced terrestrial ecologists using the best practice and acknowledged methodologies in the current scientific literature, there is reasonable confidence that data used for the analyses is accurate. However, there is uncertainty associated with the overall levels of effects of sensory disturbances and invasive species on terrestrial species and habitats. Data has been collected using consistent methodology in all sites. However, due to access restrictions and time limitations, different habitats could not be sampled at the same intensity. Nevertheless, there is reasonable confidence that the data existing collected allows for reliable interpretation of the terrestrial species and ecosystems within the LSA. Expert ecologists (which included local and international experts) designed the methods, data collection and analysis, minimising any potential errors in the data collection and handling. In all the circumstances where the quantity and quality of data has not been sufficient to establish solid conclusions, the precautionary approach has been taken. Although there is uncertainty associated with some of the effects that the potential effects (e.g., noise, light, invasive species) may have on the terrestrial species, the models selected to predict effects are the most precise possible. There is limited pre-existing information available on some the VC detected in the LSA (especially for the potential new species). However, pre-existing information of the effects assessed on comparable terrestrial species provides a good reference to understand what the potential effects are on the valued components. Mitigation will be in place to reduce the chance of effects affecting the terrestrial ecosystems. All mitigation measures have been selected based on previous knowledge and applying the best existing practice in the current literature. Therefore, it is expected that mitigation measures will be effective. Therefore, the confidence in those predictions is moderate What is the Effect of the Project on Terrestrial Species of Concern? Russet-Tailed Thrush (Zoothera heinei) Effects Assessment One specimen of this species was identified in the lowland forest vegetation community. The specimen was forwarded to the American Museum of Natural History (AMNH) for identification. Initial information from AMNH indicates that the specimen is a juvenile Zoothera heinei and, therefore, represents a range extension of the species. Due to limited knowledge of this species an assessment of Project effects on lowland forest (the species s habitat) was completed. Calculations of the total area of clearing of the habitat were undertaken in relation to the total area of available habitat within the LSA. This resulted in a loss of 371 hectares, or 8% of the potential habitat for this species in the LSA (Table 6.2-1). The loss of this amount of habitat, relative to the potential habitat in the wider Santa Isabel island, is considered minimal. Additionally, the habitat loss is not expected to result in any effects to the species population, reproduction or mating success. Populations of this species may migrate away from the affected areas into other areas of the LSA or RSA as a result of disturbance by the Project. They may also acclimatise to the disturbance effects over the short to medium term.

108 SMM Solomon Ltd Volume 3 Impact Classification The loss of any individuals of this species is considered negative. The magnitude of the effects is considered low based on the fact that less than 10% of the current identified species habitat (lowland forest) is expected to be affected by the Project. The geographical extent of effects on this species is considered local, with effects only expected to occur in the LSA. The duration of effects of the Project on this species is expected to be medium term because loss of potential habitat quality is expected to occur for the duration of the Project. The frequency of the effects on the species is expected to be negligible as the habitat is removed once, and the effects are potentially reversible. Based on the above, the residual impact level on this species is considered to be low (Table 6.2-3). The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on the Russet-tailed Thrush (Zoothera heinii) is moderate (Table 6.2-3). This is due to this species potentially being new to science or a range-restricted species. Prediction of Confidence A detailed prediction of overall confidence is presented in Section Only one specimen of this species was recorded in the LSA. That specimen, according to the AMNH could be a range extension for the species found on Guadalcanal. Further, targeted surveys are required to identify the area of extent and area of occupancy of this species on Santa Isabel, and determine if it truly was a vagrant. Based on this, a precautionary approach was followed to assess the effects to this species. Therefore the confidence in those predictions is moderate Undescribed Orchid (Liparis sp.) Effects Assessment One specimen of this species was identified in the lowland forest community outside of the Project footprint. The specimen is currently with the Solomon Islands herbarium being identified. This is a potentially new species to science, so little is known about the species s population, reproduction or habitat. Due to the limited knowledge of this species, an assessment of Project effect on lowland forest (species habitat) was undertaken as a surrogate for effects to the species. Calculations of the total area of habitat to be cleared (lowland forest) were undertaken in relation to the total area of available habitat in the LSA. This resulted in a loss of 371 hectares, or 8% of the potential habitat for this species in the LSA (Table 2.6-1). The loss of this amount of habitat, relative to the potential habitat in the wider Santa Isabel Island, is considered minimal. The effect of clearing and loss of habitat on this species, by the Project activities, may result in the loss of individuals. However, mitigation measures are in place to relocate the species if it is identified in areas to be cleared. Effects of the Project on this species, except direct clearing, are expected to be minimal. Impact Classification The direction of the effects from the Project on the individuals of this species are considered negative. The magnitude is expected to be negligible as the Project will not directly affect the known location of the specimen. However further populations of this species are likely occur within lowland forest. Nevertheless, the effect of the Project on this species is considered in the context of effects on this species s habitat (lowland forest). The Project will result in 8% of lowland forest being directly cleared. Therefore, taking this precautionary approach, the magnitude of effects is considered low because less than 10% (Table 2.2-1) of the current identified species habitat is expected to be cleared. The geographical extent of effects on this species is considered local as effects are only expected to occur in the LSA. The duration of effects of the Project on this species is expected to be medium term, because loss of potential habitat is expected to occur for the duration of the Project. The

109 SMM Solomon Ltd Volume 3 frequency of the effects on the species is expected to be negligible as the habitat is removed once. The effects are reversible if rehabilitation is successful and the species can be relocated. Based on the above, the residual impact level on this species is considered to be low (Table 6.2-3). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects on this undescribed orchid is moderate (Table 6.2-3). This is due to this species potentially being new to science or a range-restricted species. Prediction of Confidence A detailed prediction of overall confidence is presented in Section Only one specimen of this species was recorded outside of the LSA. That specimen is currently being named. Further, targeted surveys are required to identify the area of extent and area of occupancy of this species on Santa Isabel Island, and determine if it is a new species to science. Based on this, a precautionary approach was followed to assess the effects to this species. Therefore the confidence in those predictions is moderate Sago Palm (Metroxylon salomonense) Effects Assessment One specimen of this species was identified within a freshwater swamp community outside of the Project footprint. Calculations of the total area of clearing of the species habitat (freshwater swamp) were undertaken in relation to the total area of available habitat in the LSA and RSA. Only 4 ha, or 0.4% (Table 6.2-1) of this forest community in the LSA will be cleared. Therefore, effects of the Project on this species are expected to be negligible because suitable habitat occurs outside of the Project footprint. Impact Classification The direction of the effects from the Project on the species is considered negative. The magnitude of effects is considered to have no effect because less than 1% of the current identified species s habitat (freshwater swamp) will be cleared by the Project. The geographical extent of effects on this species is considered local with effects only expected to occur within the LSA. The duration of effects of the Project on this species is expected to be medium term as loss of potential habitat is expected to occur for the duration of the Project. The frequency of the effects on the species is expected to be negligible as the removed habitat is considered to occur once. Effects are potentially reversible if rehabilitation is successful. Therefore, based on the above, the residual impact level to this species is low (Table 6.2-3). The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on Sago Palm is minor (Table 6.2-3). This is due to this species being of local significance. Prediction of Confidence A detailed prediction of overall confidence is presented in Section Only one specimen of this species was recorded inside the LSA. This species is widely distributed in Solomon Islands and is utilised by the local people. Further, targeted surveys are required to identify the area of extent and area of occupancy of this species on Santa Isabel Island and the RSA. Based on this, a precautionary approach was followed to assess the effects to this species. Therefore the confidence in those predictions is high.

110 SMM Solomon Ltd Volume Tubi (Xanthostemon melanoxylon) Effects Assessment This species was identified within lowland forest, particularly in areas associated with nickel deposits (ultramafic communities). This species was identified within lowland forest in the LSA, of which, 8% will be directly cleared. Effects of the Project on this species will include the direct removal of a number of individuals, and the removal and replacement of soil seed banks. This species is identified as one of the main re-vegetation and forestry species to be replanted as part of rehabilitation. Seed collection and reproduction via cuttings is currently being undertaken as part of the nursery establishment and rehabilitation trials. This process is expected to result in limited effects relating to genetic and population loss. Impact Classification The direction of the effects on this species is considered negative. The magnitude of the effects is considered low because less than 10% of the current identified species habitat (lowland forest) is expected to be affected by the Project (Table 6.2-1). It is recognised that this species tends to be associated with nickel deposits. As such, only portions of the lowland forest community are suitable habitat. Nevertheless, the conservative estimate of less than 10% habitat loss for this species was deemed appropriate because of its known wider distribution on non-economically-viable nickel deposits in the wider area. The geographical extent of effects on this species is considered local with effects only expected to occur in the LSA. The duration of effects is expected to be medium term because loss of potential habitat quality is expected to occur for the duration of the Project until rehabilitation is successful. The frequency of the effects on the species is negligible as the habitat is only cleared once. The effects are reversible as long as the rehabilitation is successful. Based on the above, the residual impact level is low (Table 6.2-3). The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on Tubi is minor (Table 6.2-3). This is due to this species being of local significance. Prediction of Confidence A detailed prediction of overall confidence is presented in Section This species was recorded inside and outside of the LSA. This species is distributed on Choiseul and Santa Isabel Islands in Solomon Islands, and is associated with nickel deposits. Therefore the confidence in those predictions of effects is high Green Snail (Papustyla sp./papustyla pulcherrima) Effects Assessment A number of specimens of this species were collected in freshwater swamp habitat. The specimens are currently in storage awaiting positive identification. This is a potentially new species, hence, little is known about its population, reproduction or habitat. What is known is that all the specimens were collected within freshwater swamp communities outside of the Project footprint. Given this, the effect of the Project on this species will include the direct loss of approximately 4 ha (0.4%) of habitat (freshwater swamp) (Table 6.2-1), and there is the potential for mortality of individuals during the clearing process. It is unlikely that the Project will affect the viability of the population given the potential for its wider distribution in suitable freshwater swamp habitat in the wider RSA and the region. Impact Classification The effect on this species will be negative. The magnitude of the effects is considered to be low because less than 10% of the habitat will be directly affected (4 ha (0.4% of the LSA) of

111 SMM Solomon Ltd Volume 3 habitat). The geographical extent of effects on this species is considered local, with effects only expected within the LSA. The duration of effects is expected to be in the medium term because loss of potential habitat quality is expected to occur for the duration of the Project. The frequency of the effects on the species is expected to be negligible as the removed habitat is considered to occur once. The effects are reversible provided rehabilitation is successful. Based on the above, the residual impact level is low (Table 6.2-3). The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on this undescribed species is moderate (Table 6.2-3). This is due to this species potentially being new to science or a range-restricted species. Prediction of Confidence A detailed prediction of overall confidence is presented in Section Several specimens of this species were recorded inside and outside of the LSA. The specimens are still awaiting formal identification. Further, targeted surveys are required to identify the area of extent and area of occupancy of this species on Santa Isabel Island, and determine if it is a new species to science. Based on this, a precautionary approach was followed to assess the effects to this species. Therefore, the confidence in those predictions is moderate to high Lowland Forest Diversity Effects Assessment The diversity of the lowland forest vegetation type, and the habitat it provides, supports a number of SoC, which include threatened species, restricted range species, and species of cultural significance (Section 2.6.2). Calculations of the total area of clearing of the community were undertaken in relation to the total area of available habitat within the LSA. This resulted in a loss of 371 hectares, or 8% of the community in the LSA (Table 6.2-1). The loss of this amount of community, relative to the amount in the wider Santa Isabel Island, is considered minimal. Impact Classification The effect on this community is negative. The magnitude of the Project s effects is considered low because 8% of extent of this community be cleared within the LSA. The geographical extent of effects on this species is considered local with effects only expected to occur on this species within the LSA. The duration of effects of the Project on this community is expected to be medium term because loss of the community is expected to occur for the duration of the Project. The frequency of the effects on the community is expected to be negligible because it is only cleared once. The effects are reversible if rehabilitation is successful. Based on the above, the residual impact level is low (Table 6.2-3). The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on this undescribed species is minor (Table 6.2-3). This is due to this community supporting a range of SoC. Prediction of Confidence A detailed prediction of overall confidence is presented in Section This vegetation community is widely distributed across the RSA and the wider Santa Isabel Island. Based on this, a precautionary approach was followed to assess the effects to this community. Therefore, the confidence in those predictions is moderate to high.

112 SMM Solomon Ltd Volume 3 Table 6.2-3: Residual Effects on Terrestrial Species of Concern Indicator Potential effect Direction Magnitude Geographic Extent Duration Frequency Reversibility Effect Level Sensitivity Overall Impact Species population, available habitat after clearing Loss of Russet-Tailed Thrush Zoothera heinei Loss of Liparis sp. Unknown Orchid Negative Low Local Medium Term Negative Low Local Medium Term Negligible Reversible Low High Moderate Negligible Reversible Low High Moderate Loss of Metroxylon salomonense Sago palm Negative Low Local Medium Term Negligible Reversible Low Medium Minor Loss of Xanthostemon melanoxylon Tubi, Ivory wood Negative Low Local Medium Term Negligible Reversible Low Medium Minor Loss of Papustyla sp / Papustyla pulcherrima Negative Low Local Medium Term Negligible Reversible Low High Moderate Total available habitat, Species populations Loss of SoC s (Lowland Forest) Negative Low Local Medium Term Negligible Reversible Low High Moderate

113 SMM Solomon Ltd Volume Freshwater Ecology The following section assesses the residual effects that the Project may have on freshwater VCs. The only valid effects pathways for freshwater ecology is the potential loss of headwater aquatic habitat in the Nuha River, Jejevo River (east) and Sivoko River catchments during the construction and operation phases. Effects resulting from the potential loss of aquatic habitat are assessed with respect to freshwater ecology key questions and defined indicators (habitat quantity and quality, habitat connectivity and species abundance and distribution) What is the Effect of the Project on Freshwater Habitat? Effects Assessment Loss of Aquatic Habitat Land and vegetation clearance for the Project will result in the disturbance of small headwater tributaries (first order). Fifteen headwater tributaries have been identified as being potentially affected in the mine operational area. All watercourses in the LSA, including headwater tributaries are classed as VCs. The number of potentially-affected tributaries includes 11 in the upper Nuha River, three in the upper Jejevo River (east) and a single tributary in the upper Sivoko River. The small headwater tributaries drain steep terrain and are characterised by high-energy chute, pool and waterfall habitats. During the operations phase, headwater tributaries will be diverted around mining operations and will result in the permanent loss of natural first order stream habitat. Newly constructed channels will be constructed in stable bedrock or rocky geology, and of similar dimensions, so that instantaneous flow rates will not exceed historical conditions or cause additional sediment generation through channel or streambank erosion. Standard engineering practices will be employed to mitigate high velocity flow conditions with energy dissipater structures or other engineered measures to reduce the transition of velocities in the discharge from the constructed channel to the natural channel. A summary of the approximate total lengths of small headwater tributary (first order) sections in the LSA that may be affected is presented in Table Tributary lengths were measured from the Solomon Islands Department of Lands and Surveys map series 1:50,000 (X715 edition1-si50k). A total length of 5,277 m of headwater tributary habitat will potentially be lost during mine operations and represents 1.5% of the total river length (353,794 m) in the LSA (excluding the unaffected Hughukapote River) (Table 6.3-1). The potential loss will be greatest in the upper Nuha River catchment (2,803 m), followed by the upper Jejevo River (east) catchment (2,198 m) and upper Sivoko River catchment (257 m). The percentage loss of headwater tributary length represents 1.9% (Nuha River), 1.2% (Jejevo River (east)) and 1.1% (Sivoko River) of total lengths for each catchment in the LSA (Table 6.3-1). The magnitude of the effect is low given the small percentage of total river length that will be affected in the LSA (Table and Table 6.3-2). Table 6.3-1: Aquatic Habitat Loss Catchment Number of Tributaries Total River Length in LSA [m] Affected Tributary Length [m] Percentage of River in LSA Affected [%] Jejevo River (east) 8 178,539 2, Nuha River ,886 2, Sivoko River 1 24, Total ,794 5,

114 SMM Solomon Ltd Volume 3 The removal of approximately 2,865 m of first order headwater tributary habitat will result in an adverse effect along 23% of their total lengths (Table 6.3-1). Given there will be a permanent loss of natural first order headwater tributary habitat, enhancement of the constructed diversion channels will be undertaken during the closure phase (or operations phase if practicable) to offset lost aquatic habitat. The construction and rehabilitation of constructed channels will not only provide potential habitat for aquatic macroinvertebrates, but also provide important ecological functions, such as attenuating downstream surface water flows, provide a source of woody debris, leaf litter and shade, which benefits downstream aquatic environments. Sedimentation and Smothering of Benthic Habitat (Road Runoff and River Crossings) The construction, operation and decommissioning of roads (i.e., haul and access) and river crossings (i.e., culverts and bridges) has the potential to generate sediment. Sediment runoff generated from unsealed road surfaces and during the construction of river crossings has the potential to enter watercourses and cause adverse freshwater ecological effects. High flows in the vicinity of established river crossing structures can also cause localised streambank and channel erosion due to flows being constrained. Sediment and erosion control measures will be implemented and include gutters, pocket ponds to capture larger sediment particles close to source, cross-road drains, grading, armouring of drainage channels and rock check dams for velocity control (Volume 2, Appendix H). The input of sediments generated from unsealed roads and river crossings may result in adverse effects on freshwater habitat through the smothering of surfaces (affecting algae and macroinvertebrates), infilling of interstitial spaces (affecting macroinvertebrates and fish spawning) and causing an overall shift in substrate composition to that of higher proportions of sand/silt. Sediment inputs can also result in a reduction in water quality (i.e., decrease dissolved oxygen, increased turbidity, bound contaminant inputs) and adversely affect aquatic biota such as filter feeding macroinvertebrates and sight feeding fish Impact Classification Loss of Aquatic Habitat The effect aquatic habitat loss will be negative. The magnitude of the effect is high (>15%) if only the affected headwater tributaries, as a unique habitat type within the LSA are considered (Table and Table 6.3-2). However, if consideration is made to the potential that the LSA supports a large number of these headwater tributaries, the magnitude will become low. Mining operations causing the potential loss of headwater tributaries in the upper Jejevo River (east), upper Nuha River and upper Sivoko River will be limited to the LSA so the geographic extent will be local. The duration of the effect will be into the Far Future, because the replacement channels constructed during the rehabilitation stage will take time to stabilise and obtain ecological functions approaching that of natural headwater watercourses. The frequency of the disturbance will be negligible as land and vegetation clearance during mining operations will occur once. Effects will be irreversible, because once removed, affected sections and their replacement channels will no longer represent natural headwater habitats (although providing habitat). Based on the above, the predicted residual impact level of the Project on freshwater ecology habitat VCs, caused by the loss of aquatic habitat in first order headwater tributaries will be low (Table 6.3-2).

115 SMM Solomon Ltd Volume 3 Table 6.3-2: Residual Effects of Loss of Aquatic Habitat on Habitat Valued Components H Valued Component (a) Jejevo River (east) Direction Magnitude Geographic Extent Duration Frequency Reversibility Impact Level Sensitivity Overall Impact Negative Low Local Far Future Negligible Irreversible Low Medium Minor Nuha River Negative Low Local Far Future Negligible Irreversible Low Medium Minor Sivoko River Negative Low Local Far Future Negligible Irreversible Low Medium Minor (a) H = habitat VC The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects on freshwater habitat is minor (Table 6.3-2). This is due to this habitat supporting a range of SoC, and being important in the local area. Sedimentation and Smothering of Benthic Habitat (Road Runoff and River Crossings) The effects to aquatic habitat will be negative. The magnitude of sediment-related effects associated with roads and river crossings on aquatic habitat in the Jejevo River (east) and Hughukapote River will be negligible as roads will only cross a small number of first order headwater tributaries. The magnitude will be low for the Sivoko River as roads will cross a greater number of tributaries and increasing the potential for downstream effects. The magnitude of effects in the Nuha River will also be low as the mainstem of the lower Nuha River and a number of steep headwater tributaries will be crossed (Table 6.3-3). The geographical extent will be within the LSA so potential effects will be local. The duration of potential effects is expected to be long-term. The frequency of potential sedimentation and smothering of aquatic habitat is high due to high precipitation rates and the steep topography meaning sediment generated from roads and at river crossings will occur frequently. Effects will however be reversible as sediments are transported downstream and will cease in the long-term when roads and river crossings cease to be used and are rehabilitated. Based on the above, the predicted residual impact level of the Project on freshwater ecology habitat, caused by sedimentation and smothering, will be negligible in the Jejevo River (east) and Hughukapote River and low in the Nuha River and Sivoko River (Table 6.3-3). Table 6.3-3: Residual Effects of Sedimentation and Smothering of Benthic Habitat on Habitat Valued Components H Valued Component (a) Jejevo River (east) Direction Magnitude Geographic Extent Duration Frequency Reversibility Impact Level Sensitivity Overall Impact Negative Negligible Local Long-term High Reversible Negligible Medium Negligible Nuha River Negative Low Local Long-term High Reversible Negligible Medium Negligible Sivoko River Negative Low Local Long-term High Reversible Low Medium Minor Hughukapote River (a) H = habitat VC Negative Negligible Local Long-term High Reversible Low Medium Minor The overall impact classification (that is, assessing impact rating and sensitivity) for the effects on freshwater habitat is negligible to minor (Table 6.3-3). This is due to this habitat supporting a range of SoC, and being important in the local area.

116 SMM Solomon Ltd Volume 3 Prediction of Confidence Aquatic habitat is widely distributed across the RSA and the wider Santa Isabel Island. Based on this, a precautionary approach was followed to assess the effects to this VC. Therefore the confidence in those predictions is moderate to high What is the Effect of the Project on Freshwater Valued Components? Effects Assessment Loss of Aquatic Habitat The permanent loss of sections of natural first-order headwater tributary habitat during construction and operations phases will result in adverse effects through the loss of aquatic fauna through direct disturbance. The small headwater tributaries drain steep terrain and are characterised by chute-pool and waterfall habitats that support sparse fish faunas likely to include species with good climbing ability (e.g., eels and Gobiidae). The baseline survey found the fish community in the headwaters of the Hughukapote River was of low abundance (two individuals) and diversity (Anguilla marmorata eel and Giuris margaritacea eleotrid). The fish fauna in the upper Hughukapote River is likely to be representative of the headwater tributaries that will be disturbed. The presence of a large adult Anguilla marmorata from the headwater reaches of the Hughukapote River is of interest, because this species is long living, a potential food resource (VC), and can migrate into small headwater reaches. Gobiidae fish have excellent climbing ability, and can also migrate into headwater watercourses. Anguilla marmorata and Gobiidae occur throughout the LSA and do not rely on headwater habitats to complete their life cycles. The likely absence of other fish species in small headwater tributaries due to habitat constraints and access (i.e., steep and turbulent) means that other species were not considered in the impact assessment. Aquatic macroinvertebrates are likely to be the main fauna living in the headwater tributary sections that will be affected, and, include all VCs, except Batissa violacea (bivalve), which only occurs in the lower reaches. Of particular interest, was the presence of the potential new species of Tateidae snail in the upper Nuha River catchment. Upper catchment watercourses were identified as potential critical habitat for these snails. Further fieldwork is however required to determine the area of extent and area of occupancy of these snails in the LSA and RSA, and whether they occur in headwater reaches of the type draining the mine operation area. Unlike fish, macroinvertebrates are small in size, slow moving, and are more likely to be unable to actively avoid direct disturbance. Sedimentation and Smothering of Benthic Habitat (Road Runoff and River Crossings) Sediment related effects VCs may occur through the smothering of benthic habitat (i.e., affecting algae and macroinvertebrates), infilling of interstitial spaces (i.e., affecting macroinvertebrates and fish spawning), increasing turbidity (affecting primary production and filter feeders), and reducing food quality and abundance (i.e., algal growth for macroinvertebrate scrapers and herbivorous fish). Most rivers in the LSA are exposed to short-term elevated turbidity levels due to high precipitation rates and natural sediment runoff. An increase in fine sediment inputs has the potential to increase background turbidity levels and limit the depth and rate of algal growth as potential food items. Rivers in the LSA have naturally coarse streambeds dominated by gravel and cobble sized sediment. The aquatic flora and fauna present reflects the coarse nature of the streambed substrate with a high proportion of benthic aquatic insects (e.g., VC Deleatidium sp.) and gastropods making up macroinvertebrate communities. These macroinvertebrate groups typically feed on thin algal films that dominate the periphyton communities and are indicative

117 SMM Solomon Ltd Volume 3 of clean river systems. Fish in Gobiidae family (VCs) are also benthic dwellers that feed on insects and thin algal films. Gobiidae is a diverse, widespread and abundant family of fish in the LSA, and with Deleatidium sp. (sediment sensitive benthic dwelling mayfly), Tateidae (algal scraper), Macrobrachium spp. and Caridina spp. (benthic dwellers), and Batissa violacea (filterfeeding bivalve), are VCs that may potentially be most affected by the addition of sediment to the aquatic environment Impact Classification Loss of Aquatic Habitat The effects from the loss of aquatic habitat are negative. The magnitude of effects ranges for the different VCs between moderate for Tateidae snails and low for all other taxa (Deleatidium sp., Macrobrachium spp. and Caridina spp., Gobiidae and Anguilla marmorata). The magnitude of the effect for Tateidae snails is moderate, and greater than that for other VCs, because these snails appear to be found in upper catchment watercourses only, and may have populations in the headwater tributary sections within the mine operation area. The magnitude of the effect is low for all other VCs due to their widespread and abundant populations throughout the LSA and the localised nature of the impact in first order headwater tributaries. Effects on VCs will be limited to the LSA, so the geographic extent will be local. Effects will occur during the operations phase so the duration of effects will be over the medium term. The frequency will be negligible as effects will only occur once when each tributary section is disturbed. Effects will be irreversible as disturbed habitat will be lost even though replacement or diversion channels will be constructed. Based on the above, the predicted impact level of the Project on freshwater ecology VCs, through the loss of aquatic habitat, will be low (Table 6.3-4). Table 6.3-4: Residual Effects of Loss of Aquatic Habitat on Biological and Cultural Valued Components Valued Component (a) Direction Magnitude Geographic Extent Duration Frequency Reversibility Impact Level Sensitivity Overall Impact B Tateidae Negative Moderate Local Medium Negligible Irreversible Low High Moderate C Deleatidium Negative Low Local Medium Negligible Irreversible Low Medium Minor Macrobrachium, Caridina Negative Low Local Medium Negligible Irreversible Low Medium Minor Gobiidae Negative Low Local Medium Negligible Irreversible Low Medium Minor Anguilla marmorata (a) B = biological VC; C = cultural VC. Negative Low Local Medium Negligible Irreversible Low Medium Minor The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects on the VCs ranges from moderate for the Tataeidae snails to minor for all the others (Table 6.3-4). In the case of the Tataeidae snails, this species is potentially new to science. The other VCs are culturally important. Sedimentation and Smothering of Benthic Habitat (Road Runoff and River Crossings) The effects to VCs from smothering and sedimentation are negative. The magnitude of sedimentation effects caused by road runoff and river crossings is low for VCs due to the

118 SMM Solomon Ltd Volume 3 localised nature of effects in the downstream vicinity of roads, crossings and inflows from treatment devices. All VCs (Anguilla marmorata, Kuhlia marginata and Crenimugil crenilabis) are less sensitive to sedimentation effects due to their habitat preferences, tolerance of sand/silt substrates or feeding strategy so the magnitude of the effects on these biota will be negligible (Table 6.3-5). The geographical extent will be in the LSA so potential effects will be local. The duration of potential effects on VCs may extend into the long-term. The frequency of potential effects will be high due to high precipitation rates and steep topography in the catchments but will be reversible when roads are no longer used and are rehabilitated. Based on the above, the predicted impact level of the Project on freshwater ecology VCs, through sedimentation and smothering, will be low on VCs (Tateidae, Deleatidium sp., Macrobrachium spp., Caridina spp. and Gobiidae) and Batissa violacea will be low, and negligible on remaining VCs (Anguilla marmorata, Kuhlia marginata and Crenimugil crenilabis) (Table 6.3-5). The overall impact classification (i.e., assessing impact rating and sensitivity) for the effects on the VCs ranges from moderate for the Tataeidae snails to negligable for all the others (Table 6.3-5). In the case of the Tataeidae snails, this species is potentially new to science. The other VCs are culturally important. Prediction of Confidence Two specimens of the Tataeidae snails were found, one inside and one outside the LSA. Those specimens are awaiting formal identification. Further, targeted surveys are required to identify the area of extent and area of occupancy of this species on Santa Isabel Island, and determine if it is a new species to science. Based on this, a precautionary approach was followed to assess the effects to this VC. Therefore, the confidence in those predictions is moderate. A high degree of confidence is assumed for the other VCs.

119 SMM Solomon Ltd Volume 3 Table 6.3-5: Residual Effects of Sedimentation and Smothering of Benthic Habitat on Biological and Cultural Valued Components Valued Component (a) Direction Magnitude Geographic Extent Duration Frequency Reversibility Impact Level Sensitivity Overall Impact B Tateidae Negative Low Local Long-term High Reversible Low High Moderate Deleatidium Negative Low Local Long-term High Reversible Low Medium Minor Macrobrachium, Caridina Negative Low Local Long-term High Reversible Low Medium Minor Gobiidae Negative Low Local Long-term High Reversible Low Medium Minor C Batissa violacea Negative Low Local Long-term High Reversible Low Medium Minor Anguilla marmorata Negative Negligible Local Long-term High Reversible Negligible Medium Negligible Kuhlia marginata Negative Negligible Local Long-term High Reversible Low Medium Minor Crenimugil crenilabis (a) B = biological VC; C = cultural VC. Negative Negligible Local Long-term High Reversible Negligible Medium Negligible

120 SMM Solomon Ltd Volume Marine Ecology The following section assesses the residual effects that the Project may have on marine VCs. A detailed assessment of the linkages identified as valid is provided below to address the marine ecology key question What is the Effect of the Project on Marine Ecology? Effects Assessment Turbidity and Sedimentation Increased concentrations of suspended sediment and associated turbidity and sedimentation will occur due to Project-related activities, particularly during the construction stage when supporting infrastructure is being established and mitigation measures are not yet implemented. During the construction phase, earthworks will be undertaken to establish supporting infrastructure and this will require land clearing that will result in mobilisation of soils from disturbed areas. The following areas will be subject to earthworks and have the potential to generate increased turbidity and sedimentation in the marine environment. sediment control structures roads ore stockpile area jetty facilities, including: jetty for loading of barges for ore export and for import of supplies (LCT landing area) passenger ferry jetty for personnel transfer, to be built on the coast west of the camp to keep small boat traffic away from ore barges laydown area accommodation camp of jetties will also require installation of piles into the seabed. Piling activities can be expected to introduce sediment into the water column, resulting in increased turbidity and sedimentation. Sediment may also be mobilised during installation of the mooring system at the transhipment mooring location. During the operation phase, increased turbidity and sedimentation may be caused by the ongoing erosion of sediment along road corridors. Further, fugitive loss or spillage of ore during transfer to the barges and reloading onto export vessels may result in water column turbidity and smothering of benthic habitat. Propeller action during movement of marine vessels, both during construction and operations activities, may increase turbidity through resuspension of sediment. Suspended sediments will disperse according to particle size and the direction and velocity of prevailing currents. Mangroves Mangroves are generally considered to be tolerant to the effects of increased turbidity and sedimentation (Victor et al. 2006) but the ability of mangroves to cope with root burial varies

121 SMM Solomon Ltd Volume 3 between species as a function of root architecture. For example, as sedimentation increases slowly over time, some mangrove species (including Rhizophora and Bruguiera) are able to develop higher root arches and can continue growing above the increasing sediment level (Ellison 1998). Mangroves can also be positively affected by an increase in natural sedimentation rates (typically 0.5 to 1 cm per year (Ellison 1998)), because sediment deposition forms new intertidal mud or sand banks suitable for mangrove colonisation. However, unnatural sedimentation (greater than 1 cm per year) from construction sites and agricultural runoff becomes harmful to mangroves as portions of their roots become buried which causes a reduction in gaseous exchange between the roots and the surrounding water. This lessens the ability of the trees to respire, which is an important physiological process (Armstrong et al. 2010). In addition, excess sediment prevents adequate light from reaching the mangrove roots (Chou et al. 2010). The specific response of the critically endangered Bruguiera hainesii to increased sedimentation is not known, although Ellison (1998) noted that when the knee roots of other Bruguiera species are completely buried, the trees will usually die. Seagrass Increased turbidity within the water column reduces light availability to seagrass. The effect that reduced light availability can have varies greatly depending on the species (Erftemeijer and Robin Lewis 2006) and the magnitude and duration of change to the natural turbidity regime. Effects can include a decrease in the plant s photosynthetic potential, thereby reducing growth rates (Gangal et al. 2012), or in more severe cases, death of seagrasses in an area (Vermaat 1997). As seagrass meadows play a vital role in stabilising coastal sediments, the loss of seagrasses from an area can further increase turbidity in the water column as sediment stability is reduced. This can create a positive feedback loop which further increases seagrass loss (Shepherd et al 2009). Increases in sedimentation rates are also known to have negative effects on seagrass populations, including reduction in seed germination (de Boer 2007). Resilience against sedimentation varies greatly between species, however it is estimated that seagrasses can withstand sedimentation increases of 2 to 13 cm per year, depending on the species (de Boer 2007). Seagrass communities within the LSA are dominated by three main species of seagrass; Thalassia hemprichii, Cymodocea rotundata and Enhalus acoroides. E. acroides has been found to grow relatively well in turbid waters with low light conditions, and can grow in areas where land runoff is most pronounced (Kiswara et al. 2005). A study by Bach et al. (1998) found that out of seven tropical seagrass species, E. acoroides was the most persistent in low light conditions. Further, both E. acoroides and T. hemprichii were reported to sustain high leaf growth rates over a broad range of light availability. Only when there are major changes in light availability are growth rates affected. Tanaka and Nakaoka (2007) found C. rotundata to also be relatively tolerant of low light conditions. Thalassodendron ciliatum and Halophila ovalis were also identified within the LSA. Both of these species were found in very low abundance and together made up approximately 0.1% of total cover. Whilst turbidity is not considered a major threat for T. ciliatum (Short et al. 2010), H. ovalis is known to have a low degree of tolerance to light deprivation (Longstaff and Dennison 1999). Seagrass surveys during the marine ecology baseline survey found that macroalgae was also present within seagrass meadows. Macroalgae composition was dominated by brown algae (in particular Sargassum) and percentage coverage of algae increased with increasing distance from the shore. Minimum light requirements are lower in brown macroalgae than

122 SMM Solomon Ltd Volume 3 seagrass and are therefore considered to be more tolerant to increases in turbidity (Dennison et al. 1993). Seagrass habitats in the LSA provide nursery areas that are considered to be critical habitat for the endangered humphead wrasse (Cheilinus undulates). Shallow Coral Reefs Turbidity and sedimentation play an important role in determining the natural distribution and structure of coral communities (Gilmour et al. 2006). However, elevated turbidity and excessive sedimentation are known to adversely affect the structure and function of coral reef ecosystems by altering both physical and biological processes (Rogers 1990). Elevated turbidity (greater than 10 mg/l) can result in reduced availability of light for photosynthesis and energy production (Rogers 1990; Wolanski and De'ath 2005). This is important as many corals (including the majority of those recorded in the LSA) rely on the energy created through a symbiotic relationship with photosynthetic dinoflagellate algae (a type of light dependent microscopic organism) called zooxanthellae to obtain the nutrition they need to survive. Elevated rates of sedimentation can also have a detrimental effect on corals because high sedimentation rates (>10mg/cm 2 /day; Rogers 1990) may smother and bury corals and the prolonged accumulation of sediment on coral tissue can results in injury and partial or complete mortality of coral colonies. The amount and type of sediment, as well as the duration of sediment exposure will influence the ability of coral to remove the sediment (Rogers 1990; Gilmour et al. 2006; Erftemeijer et al. 2012). Further, the ability to remove sediment will vary between coral species (Huston 1985; Rogers 1990) and is a complex function of morphology, orientation and growth habits (Rogers 1990; Erftemeijer et al. 2012). Impacts on corals from sedimentation can occur after short term exposure (i.e., days to weeks) (e.g., Stafford-Smith 1993, Gilmour 2002 in Gilmour et al. 2006); and persistent stress (such as that which occurs over months to years) may result in reduced growth, reduced reproductive and/or competitive ability and reduced resistance to disease (Harrison and Wallace 1990, Rogers 1990, Brown 1997 in Gilmour et al. 2006), altered growth form of colonies (Rogers 1990) or mortality. More broadly within the coral reef communities, ongoing stress caused by sedimentation may result in reduced abundance of susceptible species and a subsequent decrease in diversity as species are lost from the area. However, despite the well documented adverse effects of both elevated turbidity and increased sedimentation, it is widely reported that many types of corals can survive successfully in coastal environments that are characterised by high levels of turbidity and sedimentation (Anthony et al. 2004; Fabricius 2005). Coral reefs that develop in turbid water settings are commonly described as turbid zone reefs (Browne et al. 2012). These reefs are characterised by turbidity levels and suspended sediment loads that are frequently above those normally associated with vigorous reef growth (Browne et al. 2012). Browne et al. (2012) report that there are several long-term studies that indicate that turbid zone reefs may be resilient to sedimentation and fluctuating turbidity, as well as other disturbance events. However, Browne et al. (2012) highlight that if the frequency and or severity of disturbances increase above that which occur naturally, the period for reef recovery will be shortened, and reefs may experience high coral mortality rates, reduced species diversity and increased macro-algal cover. Coral reef habitats in the LSA provide nursery areas that are considered to be critical habitat for the endangered humphead wrasse (Cheilinus undulatus).

123 SMM Solomon Ltd Volume 3 Deeper Low-profile Reefs The benthic community at the deeper low-profile reefs in the LSA was comprised of species typical of an environment with low levels of photosynthetically active radiation. Many of the taxa observed are filter and suspension feeders or photosynthetic taxa that are tolerant of lower light levels. However, phototropic (light dependent) species (such as some corals) that were recorded on the deeper reefs are considered likely to be susceptible to the effects of increased turbidity. Phototrophic species living in environments of low photosynthetically active radiation may be close to their light tolerance thresholds. A further reduction in light caused by increased turbidity could lower light levels below that which is required for some species to survive. If this occurred, a decline of phototrophic species on the deeper reefs in the LSA will be expected. Over time, a shift in community assemblages may follow, such that phototrophic species are replaced by species that are not dependent on light (Fabricius 2005). Sedimentation could also have negative effects on the benthic communities at the deeper reefs. Increase mortality due to smothering and burial of benthic communities is known to occur with increased sedimentation (Browne et al. 2012). Importantly, crustose coralline algae, which comprised more than 80% of the available hard substrate on the deeper reefs and which are important for coral settlement, are known to be susceptible to increased sedimentation (Fabricius 2005). Therefore, increased sedimentation could lead to a decrease in the cover of coralline algae (and other taxa such as filter feeders) at the deeper reefs. Fauna Effects from Loss of Habitat Modification or loss of habitat can have indirect effects on marine mammals, marine reptiles, fish and other habitat-associated fauna. For example, the loss of structural complexity in coral reefs can lead to a decrease in both abundance and species richness of many species of fish due to the reduction in habitat, refuge and food availability (Caley and St. John 1996; Rogers 1990). Fish that are site-attached or dependent on the reef (such as parrotfish, surgeonfish and wrasse) are likely to be most susceptible to changes to, or loss of coral reefs. Larger predatory target food fish such as trevally, emperor, snapper, fusiliers and sharks will be less vulnerable as they are highly mobile and feed on other small fish or crustaceans. In particular, a loss of habitat has been found to negatively affect juvenile fish (McCormick 2012) as many species use near shore areas such as mangroves, seagrass beds and fringing coral reefs as nursery areas (Rogers 1990). For example, the endangered humphead wrasse produces pelagic eggs and larvae that have been found to settle in seagrass, hard coral and soft coral species near reef habitats (Gillett 2010). Juveniles are typically found near inshore reefs or lagoons (Gillett 2010), and seagrasses and coral reefs that are backed by seagrasses provide some of the most valuable habitats for humphead wrasse (Dorenbosch et al. 2006). Other animals, such as commercially important bêchede-mer, also use seagrass meadows as nursery areas (Dance et al. 2003). In contrast, highly mobile fauna (such as dolphins, dugongs and turtles) that forage over wide areas are less likely to be affected by changes to habitats that occur at a localised scale. A possible exception applies to turtles as sediment characteristics are a factor in the suitability of a beach for nesting. Therefore, increased sedimentation has the potential to influence turtle behaviour.

124 SMM Solomon Ltd Volume 3 Other Effects In addition to changes to habitat, other effects on fauna that may result from increased turbidity and sedimentation include behavioural changes, such as altered foraging rates or the ability of fish to detect both prey and predators (Robertson et al. 2006), or direct effects, such as mortality or impaired health. For example, many benthic animals are sensitive to burial or smothering by sediment, particularly sessile or sedentary animals (for example, corals, oysters and mud clams) because they are unable to move away from the affected area. Increased suspended particulate matter can also cause interference with the food intake of filter-feeding animals (i.e., clams) (Karleskint et al. 2010) or clog or damage gills in fish (Sutherland and Meyer 2007). Direct Loss of Marine Habitat Project activities that have the potential to result in direct loss of marine habitat include the installation of coastal and marine infrastructure and seabed and shore erosion. These are discussed in more detail below. Installation of coastal and marine infrastructure in the vicinity of the ore export and passenger jetties, establishment of the transhipment mooring, and land clearing for on-land infrastructure, including haul and access roads, may lead to the direct loss of the following marine habitat types: coastal and riverine mangrove forest seagrass meadows fringing coral reef Habitat loss will occur directly under each pile installed to support the jetties and any associated submerged ramps, as well as any anchoring structures on the seabed beneath the transhipment mooring location and along the pathway of the haul road and passenger ferry jetty access road. The loss of habitat from these areas is expected to be long-term. Additionally, buffer areas around some of the infrastructure were also considered as areas where construction activities could result in the temporary loss of habitat during the construction phase. It is considered likely that habitat loss in these areas would be patchy and that most habitats will largely remain intact. An estimate of the area which will experience at least some level of disturbance has been calculated for each of the infrastructure developments and each habitat type that could potentially be impacted. These estimates are expressed as a percent of the available habitat in the LSA and have been made based on habitat mapping carried out as part of the marine ecology baseline survey. Based on this information, habitat loss is expected to occur for less than 1% of coastal mangroves, approximately 2% of riverine mangroves, less than 1% of fringing reef backed with seagrass, and less than 1% of low profile reef. These areas are shown in Figure Shading of the substratum by marine infrastructure can also have an indirect effect on marine habitats, especially seagrass and coral reef habitats, potentially leading to the loss and alteration of habitat. The area potentially affected by shading has been included in the estimates of direct habitat loss as a conservative measure. The extent of habitat loss caused by seabed and shore erosion is likely to be negligible as changes to marine hydrodynamic conditions and loss of shoreline vegetation will be limited and are not expect to result in shore erosion. Marine traffic can also lead to seabed and shore erosion through turbulence or scour. However it is considered unlikely that there will be seabed erosion due to propeller wash given the deep water depths in the lagoon. Shore erosion due to waves produced by marine vessels is also unlikely to occur given the

125 SMM Solomon Ltd Volume 3 shoreline in the area consists of fringing reefs and coral sands and mitigation measures will limit the speed of vessel movements. Dredging and spoil disposal (or blasting of small patch reefs) to improve navigational access for marine vessels, which would also result in direct loss of marine habitat, is not proposed to occur. The construction of Project infrastructure will lead to the direct loss of mangroves, seagrass or coral reef habitats. Loss of habitat may also occur due to seabed and shore erosion from altered marine hydrodynamics or vessel movements. In addition to the immediate effects associated with the removal of habitat, indirect effects such as habitat fragmentation may occur. Fragmentation can reduce the continuity of habitats and can interfere with species dispersal and migration, thereby isolating populations and disrupting the flow of individual plants or animals. The effects of fragmentation are specific to the habitat type and the degree of the fragmentation (i.e., gap size in proportion to the remaining habitat). More information is provided on each of the habitats below. Mangroves The effects of fragmentation on mangrove species are not well documented and typically refer to very large-scale removal and fragmentation (i.e., tens of thousands of hectares) of mangrove forests due to deforestation. It is, therefore, difficult to quantify the potential effects of the fragmentation from habitat loss for mangroves in the LSA. However, Pinzón et al. (2003) suggest that smaller-scale disturbances (e.g., subsistence logging up to 114 m 2 gap size) can be expected to have minimal effects on mangrove diversity and ecosystem processes if they resemble natural forest dynamics (e.g., gap sizes of 65 m 2 on average from lightning strikes, insect damage and storm breakage). Pinzón et al. (2003) compared the regeneration conditions in natural and anthropogenic gaps in Micronesia, and they indicated that current harvesting practices did not seem to alter species richness, though Rhizophora apiculata might become less common as gaps were replaced gradually by Bruguiera gymnorrhiza. Seagrass The research into effects of fragmentation on seagrass habitats has also focussed on largescale events such as hurricanes and extensive rainfall events (Carlson et al. 2010). Generally, the effects of water quality changes (i.e., increases in sedimentation and turbidity) were found to exceed the effects of direct physical disturbance and that seagrass communities have demonstrated resilience to the direct physical effects of severe hurricanes. Post-disturbance recovery rates of seagrasses suggests that in areas affected by small-scale disturbance (such as construction buffer zones), recovery can occur within weeks to months. However, recovery of subtidal seagrass meadows from large-scale disturbance can take between two to four years or more in some instances (Erftemeijer and Lewis 2006). Coral Reefs Loss of habitat can lead to a loss of biodiversity in marine ecosystems, often leading to a decrease in species richness (Bonin et al. 2011). The construction of Project infrastructure, particularly the two jetties, will result in small areas of fringing reef being lost which in turn could lead to localised fragmentation of coral communities. This will however affect a small area of fringing reef. Corals found during the baseline survey to be least common to the LSA, will be most susceptible to effects from habitat loss and fragmentation. Deeper Low-profile Reefs Direct loss of deeper low-profile reef habitat is not expected to occur as the transhipment mooring facility will be installed into bare substrates to avoid loss of deeper reef habitats.

126 SMM Solomon Ltd Volume 3 Effects on Fauna The potential effects on marine fauna due to loss of habitat are discussed previously. Underwater Noise Piling activities during construction of the jetty facilities and shipping traffic during construction and operation will generate underwater noise. Note that dredging or blasting of small patch reefs to improve navigational access for marine vessels, and which would generate elevated underwater noise, is not proposed to occur. Underwater noise has the potential to lead to behaviour modification of some marine fauna, in particular marine mammals, turtles and fish. Marine mammals are acoustically sensitive as sound is important for navigation, communication, foraging and orientation. Underwater noise from jetty construction could therefore disrupt communication and echolocation pathways of marine mammals. A number of species of dolphins and whales are most sensitive to high frequency sound between 8,000 Hz to 90,000 Hz (Green and Moore 1995). Noise created by bored piling tends to be a less intensive continuous noise, rather than the pulsed high frequency sounds emitted through some other forms of piling. Bored piling is considered to be less disruptive to dolphins than other forms of piling (Wursig et al. 2000) and dolphins are known to habituate to low-level sounds such as those produced through bored piling (Green and Moore 1995). Few studies have been conducted on the effects of underwater noise on turtles, however low frequency sounds, such as those produced during bored piling, are not thought to affect turtle nesting behaviour (NT Government 2011). The extent of potential noise effects on fish is not well understood. It is known however, that intense impulsive signals such as those produced from pile drivers, can cause fish kills, and signals of a smaller magnitude can cause behavioural changes (Nedwell et al as cited in McCauley and Kent 2008). Fish hearing may be temporarily or permanently damaged by high-intensity sounds. However, the extent of damage will depend on the auditory threshold of the receiving species and this will vary from species to species (Popper and Fay 1973, 1993 as cited in McCauley and Kent 2008). Shockwaves associated with noise can result in physical damage and sometimes direct mortality to nearby fish (Caltrans 2001). In finfish, the swim bladder is the primary site of damage although the kidney, liver and spleen may also be ruptured. Studies have shown that fish eggs and larvae also may be killed or damaged from shockwaves (Popper and Hastings 2009). There is evidence that smaller fish appear to be more vulnerable to overpressure impacts than larger fish and fish near the surface are more vulnerable than deep fish (Baxter et al. 1982; Keevin and Hempen 1997). The use of bored piling rather than other piling methods will prevent the production of high frequency underwater noise and shockwaves, which can be damaging to marine fauna. As only a small number of piles are required for the jetties, piling works will be limited to a short duration during the construction phase. Avoiding construction during known breeding seasons for marine mammals, and muting the sounds of equipment used on vessels will further reduce the effects of underwater noise on sensitive marine fauna. The marine vessels required during construction and operations will generate underwater noise and vibrations which could affect marine fauna. During operations, barging of ore

127 SMM Solomon Ltd Volume 3 through the lagoon to the ocean going vessel will be relatively infrequent, occurring for about 24 hours every two weeks. Ships generate low frequency sound, generally between 5 to 500 Hz, from their propellers, motors, auxiliary machinery, gear boxes and shafts (Richardson et al. 1995). As discussed above dolphins and whales are most sensitive to much higher frequencies between 8,000 Hz to 90,000 Hz. The effect on marine reptiles is not well known however low frequencies sounds are unlikely to adversely affect behaviour. The potential impacts reported for fish are also associated with high frequency sound and shockwaves rather than low frequency noise generated by ships. High frequency noise that has been found to be harmful to marine fauna is therefore not expected to be generated by marine traffic. The soft seabed in the lagoon should also reduce underwater noise by reflecting and absorbing noise generated by marine traffic. Light The jetty facilities, barges and ocean going vessels will be lit for safety and security purposes during operations. Marine fauna are influenced by light in various ways, and can exhibit both positive and negative responses to artificial light (Depledge et al. 2010; McConnell et al. 2010; Marchesan et al. 2005). The response to light can be species-specific as well as life-stage specific. Light is used for feeding, breeding and predator avoidance and therefore marine fauna behaviour may be impacted in various ways by the introduction of artificial light (Longcore and Rich 2004). Responses to artificial light may include changes in behaviour, predator-prey dynamics, schooling, spatial distribution, migration, reproduction and changes in population dynamics (McConnell et al. 2010; Longcore and Rich 2004). There is little research on the effects of artificial light on mammals. Longcore and Rich (2004) mention the increased predation by seals on salmon in the presence of artificial lighting. In regards to cetaceans, it is considered unlikely that there would be a large effect due to localised artificial lighting associated with the port facilities as cetaceans predominantly utilise acoustic (rather than visual) senses to survey their environment. The effects of artificial lighting on marine turtles are particularly well documented. Nesting turtles can be disturbed by artificial light and may be displaced to nearby unlit beaches (Witherington and Martin 2000). Turtle hatchlings are also known to use visual cues to navigate to the water from the nest (Lohmann et al. 1996) and intense artificial light sources can attract hatchlings, causing them to become disorientated (Witherington and Martin 2000). A common reaction of fish to artificial light is to school and move towards or away from the light source (Marchesan et al. 2005). This reaction may facilitate feeding (Ryer and Olla 1999) as well as the avoidance of predators. The attraction towards the light source has been shown to vary among fish species and can be related to phylogenetic and ecological factors and also differ according to light characteristics in particular, intensity and wavelength (Marchesan et al. 2005). Marine invertebrates, such as zooplankton, exhibit diel migrations where they move up and down within the water column over a 24 hour period. Presumably this behaviour allows the zooplankton to forage in the dark conditions and thus avoid predators (Longcore and Rich 2004). Artificial lighting has been shown to decrease the diel migrations in zooplankton, both in the range of vertical movement as well as the abundance of individuals migrating (Moore et al. 2000). Studies have shown naturally high predation of zooplankton by fish on nights of full moon due to the increased illumination (Longcore and Rich 2004). Increased illumination

128 SMM Solomon Ltd Volume 3 due to human activities is likely to mimic this response, favouring the predator and consequently changing the predator-prey interactions (Longcore and Rich, 2004). With regard to corals, the effects of light pollution are poorly described. However, as broadcast spawning events in corals are triggered through moonlight and lunar cycles, in conjunction with their endogenous biological clock (Kronfeld-Schor et al. 2013); it is considered possible that some effects from artificial lighting may occur. Introduced Marine Pests A potential pathway for the introduction of non-native marine flora and fauna to local waters is through the presence of ocean-going vessels associated with the Project. Marine pests could be transported as biofouling on ship hulls and in ballast water that would require discharge into local waters if vessels arrive ballasted. The release of marine pests with ballast water discharges is most likely if ballast water is taken up in areas known to contain such species and if mid-ocean exchanges have not been undertaken. The construction and on-going operation of jetty and mooring facilities will create new pathways and habitat that could result in the introduction and spread of marine pests. Marine construction equipment brought in from overseas could harbour pest species. The nearshore movements of barge and small vessel could also lead to the spread of introduced marine pests throughout the LSA. Establishment of artificial structures and disturbances to established native marine populations in the LSA during the construction phase could provide opportunities for introduced species to colonise these habitats. Environmental disturbances during the construction and on-going operation of the facilities (i.e., sedimentation, contaminant discharges, vessel propeller wash) may also provide opportunities for marine pests to invade newly disturbed native marine assemblages. Non-indigenous marine species are marine animals or plants that are not native to Solomon Islands but have arrived in the country via pathways (known as vectors) such as shipping and other marine-based activities. The transferred species may survive to establish a reproductive population in the host environment, becoming invasive, out-competing native species and multiplying into pest proportions. Common marine pest organisms can include toxic dinoflagellates, ascidians, bryozoans, hydroids, crustaceans, molluscs, polychaete worms and aquatic weeds (NIMPIS 2014). These taxa and other potential marine pests can be present in the marine environment as a variety of life stages including larvae (i.e., plankton), unattached juveniles and motile adults inhabiting the water column, benthic species living in soft sediments and attached species colonising hard substrates. The presence of introduced species in the marine environment could result in the direct replacement of native species through competition for resources (i.e., food, space) or indirectly by flow-on effects through ecosystem or food-web changes. Therefore, introduced marine pests have the potential to directly and indirectly affect habitats that maintain ecological integrity, species of conservation concern and species of subsistence, artisanal and commercial importance. The potential for the introduction of marine pests to the LSA is dependent on the origin of ocean-going vessels (i.e., where potential marine pests could originate from), the frequency of vessel visits (i.e., the greater the number of vessel visits, the higher the risk), the vessel type and quality of vessel maintenance (i.e., hull anti-fouling). The risk of introduced marine species becoming established in the LSA is greatest for those pests being translocated from other tropical countries, as temperate species are unlikely to survive in the warmer tropical marine environment of Solomon Islands. The majority of international shipping for the Project is expected to be from Japan where ore processing will

129 SMM Solomon Ltd Volume 3 be undertaken. Therefore, it is likely that most of the species transferred will be temperate, and as such, unlikely to survive or be able to reproduce in the tropical environmental conditions. There are, however, some known marine pest species that have the potential to establish and reproduce in tropical marine environments, including the Asian date mussel (Musculista senhousia), the Pacific oyster (Crassostrea gigas), the Japanese swimming crab (Charybdis japonica) and the seaweed Sargassum muticum (NIMPIS 2014). Marine biosecurity management protocols for the Project will follow International Maritime Organization (IMO) requirements and industry good practice with respect to ballast water discharge and hull maintenance to prevent introductions of marine pests. These protocols should minimise the potential for introduction, and allow for the early detection of any potential marine pests. The degree of hull biofouling will be dependent on vessel maintenance systems, such as the regularity of hull cleaning and anti-fouling management. Ongoing regular surveillance will allow for the early detection of marine pests that may have arrived despite good shipping practices. Contamination of Water and Sediment Project activities that have the potential to impact water and sediment quality include accidental spillage of fuel during refuelling of marine vessels and mobilisation of metals from mine materials. These materials include: soil, overburden and ore at the mine site; ore stockpiles; and ore spilled during barge and ship loading. Accidental spills of fuel during refuelling of marine vessels could affect coral reefs and nearshore marine habitats by smothering and/or exert toxic effects on marine flora and fauna. While one-off acute spills of great volume have the potential to severely effect a large area, recovery is likely in the long term provided hydrocarbon degradation occurs. In contrast, chronic small spills, though probably influencing a smaller area, effectively prevent recovery and lead to cumulative impacts over time, resulting in a permanent impact. A large fuel spill in a marine environment (e.g., tens or hundreds of litres) is likely to have a locally significant effect on marine biota, with the quantity spilt, wind and wave direction and the volume of water in the receiving environment being the most important factors influencing the extent of the effect. Mangrove sediments can serve as a long-term reservoir for chronic contamination, holding hydrocarbons for periods in excess of five years (Burns et al. 1994). Mitigation measures described in Section 3.4 are expected to keep the effects from any spills highly localised. Metals mobilised from mine materials may enter the marine environment and affect marine biota through the following: Erosion of mine materials by rainfall may result in solubilisation of solids-associated metals resulting in increased concentrations of dissolved (bioavailable) metals that may report downstream to the marine environment. Erosion of the ore stockpiles may result in an increase in particulate metals and dissolved metals in drainage reporting to the marine environment. Spillage of ore may during loading of barges at the jetty facilities and unloading to ocean going vessels at the transhipment mooring location. This may result in an increase in particulate and dissolved metals in the marine environment. Increased concentrations of bioavailable metals have the potential to exert direct toxicity effects on aquatic biota or accumulate in organisms thereby presenting a risk to people consuming these aquatic resources. Results from kinetic leach tests on limonite and saprolite ore undertaken as part of the waste management studies (Volume 5, Appendix C) showed that dissolved metal levels reduce to

130 SMM Solomon Ltd Volume 3 low levels after the initial flushing event (i.e., less than water quality guidelines levels that are protective of marine aquatic ecosystems). Studies in tropical conditions elsewhere have also shown that only nickel and chromium were leached from nickel laterite ores in sufficient concentrations to cause toxicity to marine organisms, and that the soluble fractions of these metals were released within a few days (Florence et al. 1994). As described in Section 3.4, a range of mitigation measures will be implemented to avoid and minimise these impacts. Monitoring of sediment and water quality will be undertaken to monitor the effectiveness of these measures and inform the requirement for any additional measures. Collisions with Marine Fauna Marine traffic will increase within the area as a result of both construction and operation of the Project. Vessels operating within the LSA will include one 20 person passenger ferry, three 3,000 dwt barges, an 850 BHP tug boat and a 30,000 dwt ocean going vessel. Marine traffic has the potential to collide with marine fauna. The potential effects of collisions with marine fauna are described below. Collisions with vessels are a potential source of fatality for marine air-breathing vertebrates, particularly those that have a low profile in the water and are slow moving (Elvin and Taggart 2007; Work et al. 2010), such as cetaceans, dugongs and turtles which are species of conservation concern in the LSA. Research has shown that collisions can be reduced by lowering the speed of the vessel, with most lethal or serious injuries to whales avoided by travelling less than 14 knots (Laist et al. 2001). Turtles are able to frequently avoid encounters with slow moving vessels (4 km/h), but very rarely can they avoid encounters with faster moving vessels (19 km/h) (Hazel et al. 2007). Dugongs also have difficulty avoiding vessels when travelling at high speeds (Anderson 1982). Laist et al. (2001) also found that most injuries to whales were caused by vessels that were over 80 m length. Behavioural characteristics need to be considered to reduce the chance of vessel collisions with turtles. Turtles often congregate near nesting beaches during breeding seasons, therefore avoiding breeding areas during these times will assist in mitigating harmful effects (Work et al. 2010). It should also be noted that whilst the range of turtle hearing lies within the frequency spectrum of noise produced by vessels, turtles associate this noise with background noise. Therefore noise produced by vessels is not an effective mitigation technique (Hazel et al. 2007). Increased Fishing Pressure An increase in harvesting of marine resources can lead to local depletion of some marine species. A workforce will be required for construction and operations of the Project with potentially up to 150 individuals staying at the camp at any given time. Local communities will be engaged to provide food for the workforce, and this could lead to increased pressure on marine resources and species of conservation concern in the area. Increased pressure on local fisheries resources could lead to a decline of subsistence and commercially important fisheries species in the area, which in turn could impact the structure of marine communities, as well as affecting the livelihoods of the local fisherman. Fishing plays an important role in shaping coral reef ecosystems and can affect the natural balance of fish assemblages. Removing predatory or grazing fish such as rabbitfish, parrotfish and wrasse can lead to increased macroalgae growth which can adversely affect the growth of coral. Even low levels of fishing can have an effect on coral reef fish assemblages (Williams et al. 2011). Estuarine and mangrove macroinvertebrates may also be subject to increased harvesting pressure.

131 SMM Solomon Ltd Volume 3 Increased fishing pressure also poses a particular risk to species of conservation concern such as the endangered humphead wrasse. The endangered humphead wrasse is particularly vulnerable to fishing due to its large size (making it an easy target), longevity, late sexual maturation and aggregation spawning (Sadovy et al. 2003). Humphead wrasse reach sexual maturity at around five to seven years (Gillett 2010), and as a result have a low replacement rate and therefore cannot endure anything above light fishing pressure (Sadovy et al. 2003). Fishing immature humphead wrasse can be particularly damaging to the longterm survival of the species (Sadovy et al. 2008). In Solomon Islands the humphead wrasse is usually caught by baited traps, spearfishing, or hook and line fishing (Sadovy et al. 2003). Purchases of fish and other marine resources for the workforce will be done so under a sustainable procurement management plan. This may include restrictions on the number and type of fish purchased, frequency of purchases and the locations where such resources are obtained. Litter Litter associated with the construction and operation of the Project has the potential to be transported into the marine environment, adversely affecting the local marine fauna. Marine litter is generally transported from land based sources to the marine environment via rivers, rainwater, storm drains, flood events and sewage disposal (Reisser et al. 2103). Inputs of marine litter are also derived from ocean based sources, such as waste dumped overboard from ships and debris from discarded fishing gear (Quayle 1992). A compilation of literature available on marine litter shows that 60% to 80% of marine litter is made up of plastics (Derraik 2002). Most plastic debris is buoyant and is a hazard to marine fauna due to extremely long decomposition times. Marine litter has the potential to pose a threat primarily to marine mammals and turtles (Katsanevakis et al. 2007), which are species of high conservation concern that are present within the LSA. The key threats that litter poses to these species are due to ingestion and entanglement (Williams et al. 2011b). Whilst there is a possibility that marine litter may affect fish, they are not species of high conservation concern within the LSA although they are an aquatic resource of common subsidence use. Ingestion of marine litter due to misidentification as a food source poses a threat to marine fauna. Turtles are particularly vulnerable as plastic bags can be mistaken for jellyfish, a key component of a turtles diet (Quayle 1992). Additionally, at least 26 species of cetaceans have been documented to ingest various forms of plastic debris (Derraik 2002). Dugongs are also known to ingest marine litter however a risk analysis completed by the Department of Sustainability, Environment, Water, Populations and Communities (DSEWPC) found that marine litter was of potential concern to dugongs, but not a major threat (DSEWPC 2011). Ingestion of marine debris can have many harmful effects that can eventually lead to fatality, including blockage of intestinal tract, diminished food stimulus, blockage of gastric enzyme secretion, delayed ovulation and reproductive failure and lowered steroid hormone levels (Katsanevakis et al. 2007). Entanglement in marine litter is another issue threatening marine fauna, particularly due to discarded fishing gear (Derraik 2002). Entanglement in marine debris can have a number of damaging effects, including restriction of movement, restriction of feeding to the point of starvation, amputations or wounds that leave sites for infection and exhaustion or drowning of the animal (Williams et al. 2011b). Nylon monofilament drift nets are acoustically and visually undetectable by most marine animals (Quayle 1992). Whilst turtles are particularly prone to injury from entanglement, whales are also vulnerable to entanglement as they are able to get netting caught around their tails and mouths when lunging for schools of fish (Derraik 2002).

132 SMM Solomon Ltd Volume Impact Classification Turbidity and Sedimentation Direction is considered negative as increased sedimentation and turbidity can lead to habitat loss and can have detrimental effects on fauna. Magnitude is considered low as the effects of increased sediment and turbidity are considered unlikely to have any material effect on populations, ecosystems or community survival or health. Sediment transport modelling (Volume 2, Appendix G) indicates that suspended sediment concentrations in streams will not be greatly affected by Project activities during construction and operations, based on the proposed mitigation measures effectively capturing eroded soils. Geographic extent is considered regional. A combination of measurements and numerical model simulations undertaken as part of the Marine Hydrodynamics Baseline Report (Volume 2, Appendix E) indicates that the majority of terrestrial sediment inputs are retained within the inshore areas, settling rapidly adjacent to river mouths. Catchment sediment inputs are likely to be restricted laterally within the lagoon with marine hydrodynamic mixing processes diluting inputs before they reach the outer barrier reef. Given that inputs occur from multiple sources (i.e., rivers, haul road, barge loading/unloading) the cumulative area affected by all these sources is assessed to be greater than 4 km in the coastal lagoon. Duration is considered long term as increased sedimentation and turbidity will be generated for duration of the Project and the effects have the potential to persist for many years after the end of the Project. Frequency is considered moderate as increased turbidity and sedimentation from land-based inputs has the potential to occur during high rainfall events, and these events are considered to occur intermittently, but on a regular basis in the LSA. The frequency of effects from increased turbidity and sedimentation from the establishment of marine infrastructure and vessel movement are expected to fall within this range and so have not been assessed independently. The effects associated with increased sedimentation and turbidity are considered likely to be irreversible, as populations and community assemblages may not be able to return to a pre- Project state once a shift in community dynamics has occurred. Increased turbidity and sedimentation are considered to have a low impact level based on the classifications described above. Sensitivity of Valued Components For effects associated with increased turbidity and sedimentation the following sensitivities apply: Habitats are considered to have high sensitivity due to the presence of habitats that are critical for the survival of the endangered humphead wrasse. Species of conservation concern are considered to have high sensitivity due to the presence of the endangered humphead wrasse in near shore areas. Species of subsistence, artisanal or commercial importance are considered to have a medium sensitivity. The sensitivity for each of the valued components is discussed in Section

133 SMM Solomon Ltd Volume 3 Residual Impact The residual impact to the valued components was determined by the sensitivity of the valued component being applied to the impact level of the expected change based on the matrix presented in Table The residual impact of turbidity and sedimentation on habitat that maintain ecological integrity is assessed as moderate. The residual impact of turbidity and sedimentation on species of conservation concern is assessed to be moderate. The residual impact of turbidity and sedimentation on species of subsistence, artisanal or commercial importance is assessed to be minor. The residual impact classification based on the impact level criteria and the sensitivity of the valued components is provided in Table Table 6.4-1: Residual Effects for Increased Turbidity and Sedimentation Direction Magnitude Extent Duration Frequency Reversibility Habitats that Maintain Ecological Integrity Negative Low Regional Long term Species of Conservation Concern Negative Low Regional Long term Species of Subsistence, Artisanal or Commercial Importance Negative Low Regional Long term Direct Loss of Marine Habitat Impact Level Sensitivity Overall Impact Moderate No Low High Moderate Moderate No Low High Moderate Moderate No Low Medium Minor Direction is considered to be negative as direct loss of habitat is undesirable for marine fauna and flora. Magnitude is considered to be low as the extent of marine habitat loss will be limited to the footprint of the jetties, transhipment mooring and sections of the haul road and passenger ferry jetty access road. As such, the effect will be detectable but small and unlikely to have any material effect to population, ecosystem or community survival or health. Geographic extent is considered local as direct loss of habitat is expected to occur for less than 1% of coastal mangroves within the LSA, approximately 2% of riverine mangroves, less than 1% of fringing reef backed with seagrass, and less than 1% of low profile reef. The cumulative extent of direct habitat loss will be less than 4 km of coastline. These areas are shown in Figure Duration is considered far future as the loss of habitat from marine and coastal infrastructure may last for 25 years or longer. Frequency is considered negligible as habitat loss will occur only once, during construction of infrastructure.

134 SMM Solomon Ltd Volume 3 Habitat loss is considered to be reversible as habitat will either be actively rehabilitated and remediated following the end of the Project (where possible to do so) or will naturally reestablish in the longer-term. The overall impact level for direct loss of habitat from establishment of marine and coastal infrastructure is considered to be low. Sensitivity of Valued Components For effects associated with direct habitat loss the following sensitivities apply: Habitats are considered to have high sensitivity due to the presence of habitats that are critical for the survival of the endangered humphead wrasse and the potential presence of the critically endangered mangrove Bruguiera hainesii. Species of conservation concern are considered to have high sensitivity due to impacts on the endangered humphead wrasse and the critically endangered Bruguiera hainesii. Species of subsistence, artisanal or commercial importance are considered to have a medium sensitivity as not one species is essential for subsidence or commercial activities. The sensitivity for each of the valued components is discussed in Section Residual Impact The residual impact to the valued components was determined by the sensitivity of the valued component being applied to the impact level of the expected change based on the matrix presented in Section The residual impact of habitat loss on habitat and species of conservation concern was assessed to be moderate. The residual impact on species of subsistence, artisanal or commercial importance was assessed to be minor. The residual impact classification based on the impact level criteria and the sensitivity of the valued components is provided in Table Table 6.4-2: Residual Effects for Direct Loss of Habitat Direction Magnitude Extent Duration Frequency Reversibility Habitats that Maintain Ecological Integrity Impact Level Sensitivity Negative Low Local Far Future Negligible Yes Low High Moderate Species of Conservation Concern Negative Low Local Far Future Negligible Yes Low High Moderate Species of Subsistence, Artisanal or Commercial Importance Negative Low Local Far Future Negligible Yes Low Medium Minor Overall Impact

135 9,099, ,000 JIHRO 519, ,000 NUHA 521,000 JIHRO JIHRO 522,000 AREA CLASSIFICATION Cleared Area Embayment Coastal Mangrove Riverine Mangrove and Tidal Rivers Barrier Reef Barrier Reef Passage Area Estuarine Reef 523,000 JIHRO Fringing Reef backed by Seagrass (includes low, moderate and high complexity reefs) Moderate Complexity Patch Reef Rubble Dominated Patch Reef Sandy Beach Lagoon Area (includes bare substrates and deep low-profile patchy reefs) 9,099,000 SOLOMON ISLANDS NICKEL PROJECT SMM SOLOMON LTD ESTIMATES OF EXTENT OF DIRECT HABITAT LOSS 9,098,000 KOLOSIGHONI 9,098,000 Buala Kolomola Information contained on this drawing is the copyright of Golder Associates Pty. Ltd. Unauthorised use or reproduction of this plan either wholly or in part without written permission infringes copyright. Golder Associates Pty. Ltd. 9,097,000 9,096,000 9,095,000 ELEVATION 150m 0 Project Footprint Transhipment Mooring Linear Infrastructure Accommodation Camp Jetty Stockpile Other Surface Infrastructure 518, , , ,000 Dadale Logging Camp Pauo Point 522,000 Dadale Logging Camp 523,000 Kolosighone 9,097,000 9,096,000 9,095,000 LEGEND Village NOTES Trail Watercourse Named Watercourse Unnamed SSR Boundary 1. Tenement boundaries supplied by Client. 2. Base data copyright Solomon Islands Government, Ministry of Land. 3. Key Inset Bathymetry copyright National Oceanic and Atmospheric Administration (NOAA), Key Inset Terrain copyright Consultative Group on International Agricultural Research (CGIAR), ,000 Metres SCALE (at A3) 1:20,000 DATUM WGS 84, PROJECTION UTM Zone 57 South PROJECT: DATE: DRAWN: CHECKED: REVIEWED: F-Rev FEB 2014 SL EL IGG FIGURE File Location: R:\01 Client\Sumitomo\ \Programs\ArcMap\Ecology\Marine Ecology\Rev0\ F-Rev Estimates of Extent of Direct Habitat Loss.mxd