Quarterly Mangrove. Report Dredging Report 2. Quarterly Mangrove Community. Report 2. Ichthys Nearshore Environmental Monitoring Program

Transcription

1 Quarterly Mangrove Quarterly Mangrove Community Community Health Monitoring Health Report Monitoring Dredging Report Dredging Report 2 Report 2 Ichthys Nearshore Environmental Monitoring Program L384-AW-REP Prepared for INPEX May 2013

2 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Document Information Prepared for INPEX Project Name File Reference L384-AW-REP-10031_0_Quarterly Mangrove Community Health Report 2.docm Report Reference L384-AW-REP Date May 2013 Contact Information Cardno (NSW/ACT) Pty Ltd Cardno (WA) Pty Ltd Cardno (NT) Pty Ltd Level 9, The Forum 11 Harvest Terrace Level 6, 93 Mitchell Street 203 Pacific Highway West Perth WA 6005 Darwin NT 0800 St Leonards NSW 2065 Telephone: Telephone: Telephone: Facsimile: Facsimile: Facsimile: International: International: International: Document Control Version Date Author Author Initials Reviewer Reviewer Initials A 23/04/2013 Kristin Metcalfe KM Joanna Lamb JL Adam Bourke AB Peggy O Donnell POD Craig Blount CB B 1/05/2013 Kristin Metcalfe KM Joanna Lamb JL Adam Bourke AB Peggy O Donnell POD Craig Blount CB 0 3/05/2013 Kristin Metcalfe KM Joanna Lamb JL Adam Bourke AB This document is produced by Cardno solely for the benefit and use by the client in accordance with the terms of the engagement for the performance of the Services. Cardno does not and shall not assume any responsibility or liability whatsoever to any third party arising out of any use or reliance by any third party on the content of this document. Prepared for INPEX Cardno Page ii

3 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Executive Summary A Mangrove Community Health (MCH) Monitoring Program has been developed to detect potential changes in mangrove flora and fauna and to infer whether any changes are a result of dredging and/or spoil disposal activities associated with the Ichthys Project in Darwin Harbour. The program focuses on the potential impacts from increased sedimentation on the health of the four main mangrove assemblages at areas in Darwin Harbour that are predicted to receive maximum levels of sedimentation associated with dredging operations. Mangrove community health (flora and fauna) is monitored at six Impact sites and compared against natural conditions at four Control sites and refers to the benchmark provided by Baseline Phase information collected at these sites prior to the commencement of dredging. These datasets are collected in parallel with the Intertidal Sedimentation and Remote Sensing Monitoring Programs to provide a suite of early warning indicators for assessing the health of mangroves in Darwin Harbour. This report presents the findings of the second routine quarterly monitoring survey for the MCH Monitoring Program. The second survey during dredging (D2; 24 January 2013 to 18 February 2013) was undertaken approximately five months after the commencement of dredging and was executed in accordance with the methodology outlined in the Nearshore Environmental Monitoring Plan (NEMP) (Cardno 2012). This report compares data collected during Baseline Survey 2 (B2) with results from D2 and presents the results of statistical analyses undertaken to detect potential impacts on MCH associated with dredging. For the reactive flora indicator of canopy cover, the net change between Control and Impact sites from B2 to D2 (a decline of 1.0%) was far below the Level 2 trigger level (>30% net change). Although the relative decrease in canopy cover between Dredging and Baseline Phases was significant at Impact sites, it was small, and more likely due to the patchy canopy cover in the Seaward assemblage or an effect of this wet season s unusually low rainfall, rather than an effect of dredging. Other reactive flora indicators measured during D2 (i.e. seedling and sapling density, growth and survival) showed no evidence of impacts from dredging. Net change from B2 to D2 for seedling leaf growth (a decline of 4.3%), seedling node growth (a decline of 1.3%) and seedling survival (a decline of 4.2%) did not exceed the Level 2 trigger levels (>50% net change in seedling growth and survival). In a pattern similar to D1, seedling growth continued to increase from B2 and survival continued to decrease in all assemblages and Control and Impact sites. Since the Baseline Phase, the changes to seedlings are considered to reflect reduced environmental stress (i.e. increased rainfall and humidity) associated with the transition of the seasons, as well as natural variability in competition and erosion. A total of 249 species of mangrove fauna were identified during D2 from a total of 8,562 individuals. A total of nine new taxonomic records were documented in D2. To date, fauna surveys for the MCH Monitoring Program have produced a total of 48 new taxonomic records for mangrove habitats in Darwin Harbour, comprising 12 crustaceans, 11 molluscs, 11 worms, 10 ant species, 3 fish and 1 sponge. Overall, a total of 345 different species have been documented from 24,704 records during the four surveys conducted to date (B1, B2, D1 and D2). Mean richness and abundance of fauna was greater during D2, a trend that was evident at both Control and Impact sites and across all assemblages. The increases in faunal populations appear to be associated with seasonal changes, as B1/B2 were conducted in the mid-dry season and D2 during the mid-wet season. Seasonal changes include increased temperature, humidity and rainfall, greater amplitude and frequency of tidal inundation and increased freshwater inflow to mangrove habitats, particularly in the two most landward assemblages (the Tidal Flat and Hinterland Margin). The species composition, richness and abundance of invertebrate fauna differed significantly between the four main mangrove assemblages and richness typically increased from landward to seaward. Species richness and abundance was consistently highest in the Seaward (Sonneratia) assemblage. Although there was an overall increase in faunal diversity and abundance in D2, there were differences between Baseline and Dredging Phases in richness at some locations in some assemblages. Species composition and abundance also differed between Baseline and Dredging Phases; however, most of these increases are thought to be associated with the pronounced seasonal changes during the eight month period since the end of the Baseline Phase. Prepared for INPEX Cardno Page iii

4 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Photo-monitoring images taken during D2 provided context for monitoring of key flora indicators. It is evident from these images that no obvious changes in forest structure, composition or physiognomy have occurred since B1. Monitoring results adequately meet the overall objectives of the MCH Monitoring Program and no management triggers were exceeded during D2. Prepared for INPEX Cardno Page iv

5 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Glossary Term or Acronym ANOVA Anoxic mat Assemblage/Zone Benthic fauna quadrat Definition Analysis of Variance. A circular plastic disc placed on the mud surface left overnight creating localized anoxic conditions which draw animals to the surface for collection. Major mangrove community assemblages in Darwin Harbour: the Hinterland Margin, Salt Flat, Tidal Flat (Ceriops zone), Tidal Creek (Rhizophora zone) and Seaward (Sonneratia zone). Area of sediment in which benthic fauna is recorded. B1, B2 Baseline Surveys 1 and 2 undertaken prior to the commencement of dredging activities. Bray-Curtis dissimilarity index Canopy Cover Control/Reference Densiometer An index of dissimilarity between samples in the types and relative abundance of species The proportion of the forest floor covered by the tree crowns. Sites that are considered to be unaffected by dredging. Instrument for measurement of canopy cover. DSDMP Dredging and Spoil Disposal Management Plan East Arm. D1, D2 Quarterly monitoring surveys during dredging. Epifauna Free-ranging fauna Location/Site Infauna Leaf-litter Animals collected from the surface of tree trunks, roots, and tree hollows to a height of 2 m; fauna collected within and attached to rotting logs. Highly mobile animals such as shrimps and fish; fauna generally not confined to a burrow. Places where repeated sampling and measurements occurred. For this scope, locations and sites are one and the same. Animals collected from within the substratum to a depth of approximately 5-10 cm. Dead plant material, such as leaves, bark, and twigs that has been shed from plants. Prepared for INPEX Cardno Page v

6 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Term or Acronym Mangrove monitoring plot MBACI MCH NEMP Node PERMANOVA Phase Pitfall trap Sapling Seedling Station Survey Transects Definition Permanent 20 m x 20 m plot within which fauna and flora are monitored. Analytical framework which incorporates Multiple sampling times Before and After at multiple Control and Impact locations or sites. Mangrove Community Health. Nearshore Environmental Monitoring Plan (Cardno 2012). The point on a stem where a leaf is attached or has been attached (also called leaf internode). Permutational Multivariate Analysis of Variance. Sampling period in relation to dredging program (includes Baseline, Dredging and Post-dredging Phases). A below-ground trap comprised of a 150 mm plastic pot, with a smaller modified internal collar fitted to prevent fauna escaping. Traps are dug into the ground, level to the mud surface, and left overnight. A young plant >1.0 m in height and with a stem girth 20mm. A young plant <1.0 m in height. A place within the monitoring sites where sampling is done. Sampling period e.g. Baseline 1 (B1). Access route and line of sampling plots and stations from the hinterland to seaward margin. Prepared for INPEX Cardno Page vi

7 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table of Contents Executive Summary iii Glossary 1 Introduction Background Requirement to Monitor Mangrove Health Results of Baseline Phase Surveys Objectives 2 2 Methodology Sampling Design Sites Assemblages, Plots and Transects Monitoring Schedule Field Methodology Canopy Cover Seedling and Sapling Density and Recruitment Seedling Survival and Growth Fauna Photo-monitoring Laboratory Methods Statistical Analysis and Trigger Tests Statistical Design Flora Assessment Against Trigger Values Fauna Quality Control Collection of Field Data Laboratory Data Data Analysis 14 3 Results Flora Canopy Cover Seedling and Sapling Density and Recruitment Seedling Growth and Survival Photo-monitoring Fauna General Findings New Taxonomic Records Species Richness Abundance Community Composition 33 4 Discussion Mangrove Community Health Flora Canopy Cover Seedling and Sapling Density and Recruitment Seedling Growth and Survival 36 v Prepared for INPEX Cardno Page vii

8 Quarterly Mangrove Community Health Monitoring Report Dredging Report Photo-monitoring Mangrove Community Health Fauna Species Richness and Abundance Community Composition Introduced Species 39 5 Conclusions 40 6 Acknowledgements 41 7 References 42 Tables Table 1-1 Table 1-2 Table 2-1 Table 2-2 Table 3-1 Table 3-2 Table 3-3 Table 3-4 Table 3-5 Table 3-6 Table 3-7 Table 3-8 Table 3-9 Table 3-10 Overview of Intertidal Sedimentation and MCH monitoring methods and indicators 3 Intertidal Sedimentation and MCH TARP (excerpt from DSDMP) 4 Classification and location of sites for MCH monitoring 5 Field sampling dates for mangrove community health monitoring during D2 9 Summary of mean canopy cover (± SE) recorded during D2 at Control and Impact sites in the four mangrove assemblages 16 Mean percentage canopy cover (± SE) recorded during B2 and D2 for Control and Impact sites for the four mangrove assemblages 17 Summary of total mean seedling and sapling densities (per m 2 ± SE) recorded during B2 and D2 at Control and Impact sites, in the four mangrove assemblages. Change in density (D2- B2) is indicated, with a decline denoted by a minus sign (-) 19 Summary of mean leaf count and total mean % leaf change (± SE) of seedlings in monitoring plots at Control and Impact sites in the four assemblages during B2 and D2 21 Summary of mean nodes and total mean % nodal change (± SE) of Rhizophoraceae seedlings in monitoring plots at Control and Impact sites recorded during B2 and D2 for the Hinterland margin, Tidal Flat and Tidal Creek assemblages 23 Summary table for total mean survival (± SE) and net survival change (D2-D1) of seedlings in monitoring plots at Control and Impact sites recorded during D2 in the four mangrove assemblages 26 New taxonomic records for species sampled during D2 from Control and Impact sites 28 Total number of invertebrate species and individuals (in parentheses) for each taxonomic group recorded during B1, B2, D1 and D2 29 Mean total invertebrate species richness (± SE) per monitoring site for B1, B2, D1 and D2 for Control and Impact sites in the four mangrove assemblages 30 Mean total invertebrate abundance (± SE) per sampling station for B1, B2, D1 and D2 for Control and Impact sites in the four mangrove assemblages 32 Figures Figure 2-1 Location of Control sites (blue) and Impact sites (red) for Intertidal Sedimentation and MCH Monitoring Programs 6 Figure 2-2 Schematic profile diagram of the typical pattern of assemblages from landward (left) to seaward (right) observed in Darwin Harbour mangroves Source: Metcalfe Prepared for INPEX Cardno Page viii

9 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 2-3 Typical layout of transect from landward to seaward with mangrove health monitoring plots (20 m x 20 m) in each of the four main assemblages 7 Figure 2-4 Schematic representation of mangrove monitoring plots indicating the number and location of replicate sampling stations and 1 m x 1 m quadrats for different indicators of mangrove health 8 Figure 2-5 Flora monitoring methods including A) measurement of canopy cover using densiometer; B) permanent 1 m x 1 m seedling growth and survival plot; C) photo-monitoring 10 Figure 2-6 Photographs of faunal sampling methods: A) randomly placed 1 m x 1 m quadrat; B) anoxic mat; C) pitfall trap; and D) ant sampling using baits 11 Figure 3-1 Mean percentage canopy cover (± SE) in the four assemblages from landward (L) to seaward (R) recorded during D2 at Control and Impact sites 15 Figure 3-2 Mean percentage change (D2- B2) in canopy cover (± SE) in the four assemblages from landward (L) to seaward (R) 17 Figure 3-3 Mean percentage net change (D2-B2) in canopy cover (± SE) for Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>30% net change) 18 Figure 3-4 Mean seedling density (± SE) in the four assemblages from landward to seaward recorded during D2 at Control and Impact sites 19 Figure 3-5 Mean percentage change (D2- B2) in seedling density (± SE) in the four assemblages from landward to seaward 20 Figure 3-6 Mean number of leaves (± SE) on seedlings in permanent monitoring plots in the four assemblages from landward to seaward recorded during D2 21 Figure 3-7 Mean percentage change in the number of leaves (± SE) for seedlings in monitoring plots in the four assemblages from landward to seaward recorded during D2 22 Figure 3-8 Mean percentage change (D2-B2) in leaves (± SE) recorded at Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>50% net change) 23 Figure 3-9 Mean nodes (± SE) for Rhizophoraceae seedlings in monitoring plots in the Hinterland Margin, Tidal Flat and Tidal Creek assemblages recorded during D2 24 Figure 3-10 Mean percentage change in the number of nodes (± SE) for Rhizophoraceae seedlings in monitoring plots in the Hinterland margin, Tidal Flat and Tidal Creek assemblages recorded during D2 24 Figure 3-11 Mean percentage net change (D2- B2) for nodes (± SE) at Control and Impact sites (data pooled for all sites and assemblages) in comparison with the Level 2 trigger (>50% net change) 25 Figure 3-12 Mean % surviving (± SE) seedlings in monitoring plots in the four assemblages from landward to seaward recorded during D2 26 Figure 3-13 Mean percentage net change (D2- B2) in seedling survival (± SE) for Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>50% net change) 27 Figure 3-14 Mean total invertebrate species richness (± SE) in the four assemblages from landward (L) to seaward (R) recorded during B1, B2, D1 and D2 30 Figure 3-15 Mean total invertebrate abundance (± SE) in the four main assemblages from landward (L) to seaward (R) recorded during B1, B2, D1 and D2 32 Figure 3-16 Ordination of sampling stations at Control (grey) and Impact sites during B1, B2, D1 and D2 based on presence/absence of invertebrate species. Data were pooled for all sampling methods per station in each of the four assemblages 33 Figure 3-17 Ordination of sampling stations sampled during B1, B2, D1 and D2 in the four assemblages based on the presence/absence of invertebrate species 34 Figure 3-18 Ordination of sampling stations sampled during dry and wet season B1, B2, D1 and D2 based on the presence/absence of invertebrate species 35 Prepared for INPEX Cardno Page ix

10 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-19 Ordination plot of invertebrate species based on abundance for B1/B2 (blue squares), D1 (green squares), D2 (pink squares), KMPHD surveys (grey circles) and Weddell baseline surveys (black triangles) 35 Appendices Appendix A Methods Details 46 Appendix B Flora Results 46 Appendix C Fauna results 56 Appendix D Statistical Analyses 78 Appendix E Photo-Monitoring 93 Prepared for INPEX Cardno Page x

11 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 1 Introduction 1.1 Background INPEX is the operator of the Ichthys Gas Field Development Project (the Project). The Project comprises the development of offshore production facilities at the Ichthys Field in the Browse Basin, some 820 km west-south-west of Darwin, an 889 km long subsea gas export pipeline (GEP) and an onshore processing facility and product loading jetty at Blaydin Point on Middle Arm Peninsula in Darwin Harbour. To support the nearshore infrastructure at Blaydin Point, dredging works will be carried out to extend safe shipping access from near East Arm Wharf to the new product loading facilities at Blaydin Point which will be supported by piles driven into the sediment. A trench will also be dredged to seat and protect the GEP for the Darwin Harbour portion of its total length. Dredged material will be disposed at the spoil ground located approximately 12 km north-west of Lee Point. A detailed description of the dredging and spoil disposal methodology is provided in Section 2 of the Dredging and Spoil Disposal Management Plan - East Arm (DSDMP) (INPEX 2012). 1.2 Requirement to Monitor Mangrove Health Mangrove ecosystems are valued globally for their ecological role and importance as sources of nutrients for nearshore coastal ecosystems. The intertidal areas between Tapa Bay to the west and Shoal Bay to the east of Darwin contain over 33,400 hectares (ha) of mangroves (Cardno 2013a). In addition to being one of the largest discrete blocks of mangroves, this area is recognised for its diversity, containing over 30 mangrove species (McGuinness 2003; Wightman 2006). The Draft Environmental Impact Statement (EIS) (INPEX 2011) identified potential indirect impacts on mangroves from dredging generated sedimentation in intertidal areas in Darwin Harbour. Excess deposition of sediment to mangrove communities can cause tree stress owing to smothering and burial of root systems. Impacts can range from reduced vigour to death, depending on the amount and type of sedimentation and the mangrove species involved. While Ellison (1998) noted that there are insufficient data available to establish specific tolerances, on the basis of a previous mangrove monitoring study in Darwin Harbour (Metcalfe and Crawford 2007) it is considered that sedimentation levels of up to 50 mm would be generally tolerated by seaward mangrove communities throughout East Arm. However, for the purposes of impact predictions and reactive management trigger values, sensitive mangrove species (e.g. Sonneratia, Ceriops and Avicennia) were considered to be at risk of reduced plant health or growth at net deposition of less than 50 mm and tree mortality was considered likely to occur at net sedimentation rates of 50 mm or greater (INPEX 2011). The level of response and rates of recovery are likely to depend on several factors such as the timing, duration, intensity, and scale of the dredging works and the amount of net sedimentation. Modelling of the continuous (year-round) dredging scenario estimated that 42 ha of mangroves would be affected by sedimentation of 50 mm or more. The Intertidal Sedimentation and Mangrove Community Health Monitoring Program (ISMCHMP) has been designed to confirm modelled predictions and allow an opportunity to respond in order to manage impacts beyond those predicted. The program focuses on the potential impacts from dredging on mangroves within East Arm, with Control sites inside Darwin Harbour but outside East Arm. Detailed mapping and classification of Darwin Harbour mangrove assemblages using multispectral satellite imagery has been carried out by Brocklehurst and Edmeades (1996), and the assemblage categories, zone numbering and naming conventions used in that study were adopted for this monitoring program. 1.3 Results of Baseline Phase Surveys Two Baseline surveys (B1 and B2) of mangrove flora and invertebrate fauna were completed during three months from June 2012 to August 2012 (Cardno and EcoScience NT, 2012). Mangrove community health was monitored using key flora indicators comprising canopy density, seedling and Prepared for INPEX Cardno Page 1

12 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 sapling density, and seedling growth and survival while fauna was characterised by documenting species richness, abundance and composition. Canopy cover between B1 and B2 surveys was similar (overall mean 80.8% ± 1.0 SE and 80.5% ± 1.1 SE) with very little variability among sites. Canopy cover at Control sites was representative of Impact sites and hence considered suitable for comparison during dredging operations. Across the intertidal area, seedling density was generally greatest in the Seaward and Tidal Flat assemblages, and least in the Tidal Creek and Hinterland Margin, and this pattern was fairly consistent between Control and Impact sites. By contrast sapling density was small, indicating that seedling mortality was great overall with few individuals surviving to the sapling stage. With the exception of the Tidal Flat, most assemblages typically had few saplings. Baseline Phase data revealed overall patterns in seedling growth and survival were similar among the sites, but differences were evident between assemblages. Leaf counts were consistently more at Control sites than at Impact sites during B1 and B2; however, this was an inherent difference and, overall, Control sites were representative of Impact sites. Trends across the intertidal area showed that growth and survival generally increased in a seaward direction (e.g. leaf and node growth was greatest in the Tidal Creek) and variability was more pronounced in the landward assemblages. Seedling survival in the Hinterland Margin was lowest and most varied, with leaf change varying over time (i.e. plants lost and grew leaves) and between sites. Although leaf growth was greatest in the Seaward assemblage, seedling mortality was also greatest. A total of 271 mangrove faunal species were identified during B1 and B2. Analyses demonstrated no significant differences between Control and Impact sites, nor between B1 and B2. Similar to previous studies in Darwin Harbour, species composition, richness and abundance of mangrove invertebrate fauna differed significantly between the four main assemblages. Multivariate analyses indicated that the fauna recorded at the ten monitoring sites during the Baseline Phase was similar to that recorded in previous studies in Darwin Harbour. Photo-monitoring provided context for flora indicators and a benchmark for future monitoring during the dredging and post-dredging phases of the Project. The combined Baseline Phase methodologies provided a good understanding of temporal and spatial variability at the ten monitoring sites. 1.4 Objectives The Intertidal Sedimentation and Mangrove Community Health Monitoring Program (ISMCHMP) comprises three sub-programs: 1. Intertidal sedimentation; 2. Mangrove community health; and 3. Remote sensing of mangrove forests. Table 1-1 presents the techniques used and indicators for each sub-program, outlining whether they are reactive or informative. Reactive indicators are used as triggers to implement further monitoring or a management response, as outlined in the DSDMP (INPEX 2012). Data collected on informative indicators are used for interpretative purposes to determine attributability using a multiple lines of evidence approach and to support management responses if reactive triggers are exceeded during dredging and spoil disposal activities. The DSDMP includes a Trigger Action Response Plan (TARP) in which sedimentation and mangrove health trigger values are prescribed. A summary of the TARP trigger values methods of determination is provided in Table 1-2. The objectives of the ISMCHMP are to: > Detect accretion of sediment within intertidal mangrove areas attributable to dredging in East Arm; > Detect changes in mangrove health (including mangrove faunal communities) attributable to dredging in East Arm; and > Provide appropriate data to allow clear and timely determination of exceedances of management trigger levels. Prepared for INPEX Cardno Page 2

13 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 During the Dredging Phase, a Before-After Control-Impact (BACI) design will be used to assess the significance of monitoring results at Impact sites against Baseline Phase data and Control sites. The objectives of the Mangrove Community Health (MCH) component of the ISMCHMP are to: > Provide monitoring results for quarterly surveys conducted during dredging for both reactive and informative indicators; > Analyse results by comparison of Control and Impact sites monitored during dredging surveys; and > Compare baseline results with Dredging Phase data and assess changes in reactive and informative indicators. This report presents monitoring data for Dredging survey 2 (D2) that addresses the above objectives related to the MCH component of the ISMCHMP. The results of monitoring for the Intertidal Sedimentation and Remote Sensing components of the program are reported separately. Table 1-1 Overview of Intertidal Sedimentation and MCH monitoring methods and indicators Method Indicator Reactive or Informative Mangrove Health Monitoring Mangrove fauna surveys Mangrove flora Remote Sensing of Mangroves** High resolution satellite imagery Benthic fauna Epifauna Infauna Refuge pools and free-ranging fauna Fish Canopy Cover Seedling survival and growth Leaf litter fall (including stipule counts)* Seedling and sapling density and recruitment Photo-monitoring Vegetation Index (surrogate for canopy cover) Informative Reactive (Level 2 trigger) Informative Reactive (Level 3 trigger) Intertidal Sedimentation Monitoring*** Sediment stakes Marker Horizon Method TRIAL String Technique TRIAL Sedimentation levels Reactive (Level 1 / 2 trigger) Sediment characterisation ph Particle size distribution *Methods and results provided in the Primary Productivity Report **Methods and results provided in Remote Sensing Report ***Methods and results provided in Intertidal Sedimentation Report Informative Prepared for INPEX Cardno Page 3

14 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 1-2 Intertidal Sedimentation and MCH TARP (excerpt from DSDMP) Level 1 Trigger Level 2 Triggers Component Normal Situation Sedimentation Sedimentation Canopy cover Seedling survivorship and growth Trigger value Not triggered >50 mm net sedimentation OR Predicted net sedimentation rate* >50 mm/a >50 mm net sedimentation OR Predicted net sedimentation rate* >50 mm/a OR >30% net change in canopy cover AND >50% net change in seedling survivorship and growth Trigger description N/A Sedimentation will be measured at each of the impact and control monitoring sites. Net sedimentation will be determined by calculating the difference between measured and baseline bed level. Data collected from each assemblage in each impact site will be compared against its baseline level to determine whether sedimentation has increased since baseline. Sedimentation during dredging will be placed in context of what is naturally occurring over time by subtracting pooled changes in sedimentation at control sites. The result will be statistically compared against the trigger value. Level 1 sedimentation trigger occurs when >50 mm of sedimentation is measured (excess to control) at any assemblage at any site. OR When the predicted rate of net sedimentation measured during three previous consecutive surveys predicts sedimentation to be >50 mm/year (excess to control) at any assemblage at any site. Sedimentation will be measured at each of the impact and control monitoring sites. Data collected from each assemblage in each impact site will be compared against its baseline level to determine whether sedimentation has increased since baseline. Sedimentation during dredging will be placed in context of what is naturally occurring over time by subtracting pooled changes in sedimentation at control sites. The result will be statistically compared against the trigger value. Level 2 sedimentation trigger occurs when >50 mm of average sedimentation is measured (excess to control) within a mangrove assemblage for all impact sites. OR When the predicted rate of net sedimentation measured over a minimum of three previous consecutive monitoring surveys exceeds >50 mm/year (i.e. clear upward trend) within an assemblage for all impact sites. To be considered a Level 2 exceedances, the sedimentation level or predicted net sedimentation rate must also a) exceed 50 mm at a minimum of three sites; and b) be determined through measurements at additional contingency stakes installed along the transect (in between standard measurement stakes) and perpendicular to the existing transect locations. OR Canopy cover / seedling survivorship and growth will be measured at each of the impact and control monitoring sites. Net change in canopy cover / seedling survivorship and growth will be determined by calculating the difference between measured and baseline data. Net change in canopy cover / seedling survivorship and growth from impact sites and control sites will be pooled and the difference between the two will be tested against the trigger value. Where a Level 2 trigger exceedance is identified a consideration of natural range of variability in canopy / seedling survivorship and growth cover from baseline data will be made prior to management responses being implemented. Prepared for INPEX Cardno Page 4

15 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 2 Methodology A summary of the MCH Monitoring Program methodology is provided below; for full details refer to the Mangrove Community Health Monitoring Program Baseline Report (Cardno and EcoScience NT, 2012) and Appendix A of the Nearshore Environmental Monitoring Plan (NEMP) (Cardno 2012). 2.1 Sampling Design The key indicators for MCH monitoring comprised: > Canopy cover in 20 m x 20 m plots and remote sensing vegetation index data; > Seedling survivorship and growth from permanent 1 m x 1 m quadrats; > Seedling and sapling density and recruitment from randomly placed 1 m x 1 m quadrats; and > Mangrove fauna total species richness and total abundance (pooled from sampling of benthic fauna, epifauna, infauna, fauna in refuge pools, fish and ants) using a number of different methods Sites Six Impact sites (termed Locations in Results, Section 3) were selected on the basis of modelling results to coincide with those areas that were predicted to receive the maximum levels of sedimentation from dredging operations in the East Arm of Darwin Harbour. Four Control sites were selected outside of East Arm at sites that were not predicted to receive sedimentation from dredging operations (Table 2-1, Figure 2-1). A complete list of GPS co-ordinates for the ten sites can be found in Appendix A-2. Table 2-1 Classification and location of sites for MCH monitoring Where Control sites are alongside Impact sites this indicate a similarity in river geomorphology for these sites Impact Site Site Code Control Site Site Code Sadgroves Creek I1 Talc Head/Woods Inlet C1 Bleesers Creek I2 East Channel Island C2 East Arm Boat Ramp I3 Lightning Creek I4 Middle Arm C3 Elizabeth River - Creek I5 Upper Elizabeth River I6 Blackmore River Boat Ramp C4 Prepared for INPEX Cardno Page 5

16 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 2-1 Location of Control sites (blue) and Impact sites (red) for Intertidal Sedimentation and MCH Monitoring Programs Prepared for INPEX Cardno Page 6

17 Quarterly Mangrove Community Health Monitoring Report Dredging Report Assemblages, Plots and Transects Twelve distinct intertidal communities have been defined and mapped in Darwin Harbour (termed assemblages/zones by Brocklehurst and Edmeades (1996)) with four of these accounting for approximately 80% of the total mangrove area. The pattern of zonation generally evident in Darwin Harbour and the relationship between these assemblages and tidal elevation is shown in Figure 2-2. Monitoring plots were placed in each of the four main mangrove assemblages shown in Figure 2-2. At each monitoring site (see Section 2.1.1) a transect was established from landward to seaward (Figure 2-3). Apart from the two most upstream sites (C4 and I6) which lack a Seaward assemblage, permanent 20 m x 20 m monitoring plots were established in each of the four main assemblages (Figure 2-4). Figure 2-2 Schematic profile diagram of the typical pattern of assemblages from landward (left) to seaward (right) observed in Darwin Harbour mangroves Source: Metcalfe 2007 Figure 2-3 Typical layout of transect from landward to seaward with mangrove health monitoring plots (20 m x 20 m) in each of the four main assemblages Prepared for INPEX Cardno Page 7

18 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 2-4 Schematic representation of mangrove monitoring plots indicating the number and location of replicate sampling stations and 1 m x 1 m quadrats for different indicators of mangrove health At several sites the width of existing mangrove communities was not sufficient to encompass plots 20 m x 20 m in size and at two sites (I2 and I4) plot dimensions in the Seaward assemblage were modified to 10 m x 40 m, while maintaining the same 400 m 2 area as the standard-sized (20 m x 20 m) plots Monitoring Schedule Two baseline surveys (B1 and B2) of mangrove flora and invertebrate fauna were completed during three months from June 2012 to August Dredging commenced on 27 August 2012 and the first routine quarterly monitoring survey during dredging (D1) was undertaken from 27 October 2012 to 22 November Monitoring for D2 was undertaken from 24 January 2013 to 17 February 2013 (Table 2-1) and the results presented in this report refer to MCH for the period between the end of D1 (22 November 2012) and the end of D2. Completion of surveys in four mangrove assemblages located between the landward margin and the seaward fringe is heavily tide-dependent and each monitoring survey is split into two 10-day blocks (e.g. Baseline 1a and 1b, D2a and D2b) coinciding with spring tidal cycles to ensure sites are exposed for a sufficient time during low tide to complete sampling. Survey dates for D2a and D2b are provided in Table 2-2 and Appendix A-1. Prepared for INPEX Cardno Page 8

19 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 2-2 Field sampling dates for mangrove community health monitoring during D2 Site Location D2 I1 Bayview 24 to 25 January 2013 C3 Middle Arm 26 to 27 January 2013 I5 Elizabeth River- Creek 28 to 29 January 2013 I2 Bleesers Creek 30 to 31 January 2013 I6 Elizabeth River- Upstream 1 to 2 February 2013 I4 Lightning Creek (Blaydin Point) 8 to 9 February 2013 C2 Channel Is, East 10 to 11 February 2013 I3 East Arm Boat ramp 12 to 13 February 2013 C4 Blackmore River Boat ramp 14 to 15 February 2013 C1 Talc Head 16 to17 February Field Methodology Canopy Cover Canopy cover or the density of the tree canopy is a useful indicator of mangrove health, since leaf shedding and leaf growth are sensitive to a wide range of environmental factors and changes in canopy or foliage cover may be indicative of environmental stress. Within each monitoring plot, forest canopy cover was measured using a tripod-mounted Stickler s modified (17-point) spherical forestry densiometer (Stickler 1959) to provide estimates of the foliage cover (combined leaf and branch cover). Three replicate canopy cover measurements were taken from within each of the four 10 m x 10 m subplots formed by the four plot corners and the centre point in each 20 m x 20 m plot (Figure 2-4). Each measurement involved readings at a randomly selected point (located using random number tables), whilst facing north, east, south and west with a total of 48 readings from 12 replicates obtained per plot. Sticklers modified densiometer emphasizes overhead vegetation over foreground vegetation which is the main source of bias in canopy density measurements (Ode 2007). The overall canopy cover for sites in the different assemblages was calculated as the mean of readings from the 12 replicates per monitoring plot Seedling and Sapling Density and Recruitment The density of existing populations of seedlings and saplings within each monitoring plot was measured by direct counts within replicated 1 m x 1 m quadrats. Eight replicate quadrats were placed at randomly selected points (located using random number tables) in each plot (Figure 2-4). The species composition and abundance of seedlings and saplings within each random quadrat was recorded. Forest regeneration is documented by comparison of seedling densities from B1/B2 with data from the Dredging Phase and future monitoring surveys. Mean seedling and sapling density was calculated as the average per plot and mean species richness was obtained for each plot Seedling Survival and Growth Five permanent 1 m x 1 m quadrats per monitoring plot were used to document the survival and growth of existing seedlings (Figure 2-4, Figure 2-5). Due to the characteristically sparse and patchy nature of mangrove seedlings, particularly in areas of dense forest, replicate quadrats are not randomly placed in this program. Permanent monitoring quadrats were therefore established in areas where seedlings were present. Prepared for INPEX Cardno Page 9

20 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 A) B) C) Figure 2-5 Flora monitoring methods including A) measurement of canopy cover using densiometer; B) permanent 1 m x 1 m seedling growth and survival plot; C) photomonitoring Total Leaf Counts The growth of individual seedlings (seedlings being defined as plants <1 m tall and <2 cm girth) occurring within permanent quadrats were monitored by counts of the total number of leaves. Mature, but small, plants (such as the shrub Aegialitis annulata or stunted Ceriops australis) were excluded. The mean number of leaves per monitoring plot was recorded from all sites and assemblages during D2 and later compared with that recorded during B2 to obtain net change, growth and survival Total Node Counts Mangrove seedlings of species in the Rhizophoraceae family possess opposite leaves and when these are shed during active growth a visible leaf scar (or internode) persists on the main stem and on lateral branches. However, other common mangrove species, including Avicennia marina, Excoecaria ovalis, Sonneratia alba and Aegiceras corniculatum, do not produce clear leaf scars or nodes. Hence, only seedlings of Rhizophoraceae species (including Rhizophora stylosa, Ceriops australis, Ceriops decandra, Bruguiera exaristata and Bruguiera parviflora) are amenable to monitoring growth by recording the increase in node counts on the main stem (node gain per unit time). By contrast, growth of all species of mangrove can be assessed by leaf counts. The dense growth of algae on the stem of some seedlings precluded accurate measurement of leaf nodes in some individuals. These seedlings were excluded from the program, as were plants with secondary thickening and swelling of the stem with age as this substantially reduced the accuracy of counting nodes on these seedlings. Dense algal growth on seedlings precluding node counts occurred only in the seaward assemblage and mainly affected only one species (Aegiceras corniculatum), the dominant seedling species in this habitat, so only leaf counts were used to monitor growth in this species Fauna A composite field methodology developed specifically to document invertebrate biodiversity (Metcalfe 2007) was used to record the richness and abundance of each of the main macro-invertebrate groups and small resident fish found in mangroves (Figure 2-6). All molluscs, crustaceans, worms and ants (large enough to be visible to the naked eye) were monitored. Within each monitoring plot, fauna were sampled at three randomly selected sampling stations through various methods. For a detailed description of the methodology for sampling fauna, see Mangrove Community Health Monitoring Program Baseline Report (Cardno and EcoScience NT 2012). Prepared for INPEX Cardno Page 10

21 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 A) B) C) D) Figure 2-6 Photographs of faunal sampling methods: A) randomly placed 1 m x 1 m quadrat; B) anoxic mat; C) pitfall trap; and D) ant sampling using baits Photo-monitoring Four digital photographs were taken within each of the 38 monitoring plots during B1 in June During each subsequent survey, another set of photographs was taken for comparison with the B1 images. Photomonitoring images are used as a reference and to monitor mangrove health by detecting potential changes in forest structure, regeneration, species composition and physiognomy over time. The centre of each 20 m x 20 m monitoring plot, which is marked by a permanent PVC post, functions as the central point from which four photographs (landscape format) are taken during each routine monitoring survey. The photographer stands at the centre post whilst the camera is directed toward one of the four corners of each 20 m x 20 m plot. Four PVC photo-monitoring posts are located on the diagonal of each plot at a distance of 3 m from the centre to assist in the accurate relocation of photo-points. A site marker board is placed on these posts (Figure 2-5) to indicate the site ID, date and the corner number of each quadrant being photographed (e.g. C36-1, C36-2 etc.). Photos from the most recent survey are compiled and compared with those from B1 and examined for any negative changes in physiognomy and forest health that may be associated with sedimentation impacts from dredging. 2.3 Laboratory Methods Mangrove fauna to be analysed by EcoScience NT or external laboratories (e.g. Museum and Art Gallery of the Northern Territory (MAGNT), Queensland Museum and CSIRO) were accompanied by proformas with tentative identifications, site and other collection details. Copies of the laboratory management sheets were retained by each laboratory. The majority of specimen identifications were undertaken in the EcoScience NT laboratory using taxonomic keys and published literature, printed descriptive and reference information, and verified against the comprehensive reference collection of mangrove invertebrate fauna, fish and ants. Specimen identifications were confirmed by a second experienced scientist. Where species were unable to be identified using these techniques (i.e. the existing reference collection, keys and taxonomic literature), specimens were forwarded to specialist taxonomists at the MAGNT (molluscs, fish and worms), the Queensland Museum (crustaceans) and CSIRO (ants). Species that were potentially new records were forwarded to respective specialists interstate or overseas. For uncommon Prepared for INPEX Cardno Page 11

22 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 species or those with taxonomic uncertainty, voucher specimens and tissue samples for DNA analysis were retained by both EcoScience NT and MAGNT for molecular identification and future reference. 2.4 Statistical Analysis and Trigger Tests Flora and fauna data were analysed statistically using a range of descriptive, inferential, univariate and multivariate techniques Statistical Design The majority of statistical analyses were carried out using Primer 6 (version ) and PERMANOVA+ software (version 1.0.5) (Primer-E Ltd). Factors included in the analyses were: > Phase Fixed and orthogonal with two levels (Baseline and Dredging); > Survey Random and nested within Phase with four Levels (two Baseline and two Dredging); > Treatment Fixed and orthogonal with two levels (Impact and Control); > Location Random and nested within Treatment with ten levels (six Impact, four Control); and > Assemblage - Fixed and orthogonal with four levels (Hinterland Margin, Tidal Flat Ceriops, Tidal Creek Rhizophora, Seaward). Differences in flora (canopy cover, seedling density and sapling density) and fauna indicators (total invertebrate species richness and total invertebrate abundance) were tested using a five factor mixed model Analysis of Variance (ANOVA) in a Before-After Control-Impact (MBACI) framework. For the period between B2 and D2, statistical analysis of seedling growth (i.e. leaf and node counts) for all species combined, and for species found in more than one assemblage, comprised a three factor nested ANOVA with the factors: Treatment, Location (Site) and Assemblage. For individual species found in one assemblage only, analyses involved only two factors (Treatment and Location). In these analyses, no temporal comparisons were made (i.e. the factors Phase or Survey were not included) because of the potential for auto-correlation of the data. ANOVAs were done in PERMANOVA+ using Euclidean distance resemblance matrices. All default PERMANOVA+ options were used including maximum (9999) permutations (Anderson et al. 2008). Posthoc permutational t-tests were undertaken, where required, to aid in the interpretation of significant results Flora All raw data for flora were entered into Excel and prepared for tabulation or analysis in a Microsoft Access database. Examination of the data, summary statistics and graphical presentation was then carried out in MINITAB Release for Windows. For canopy cover, the four densiometer readings taken at north, south, east and west cardinal points were averaged and the means of these (three replicates in each of four quadrats in each monitoring plot) were used in analyses. For analyses of seedling and sapling density, counts of species undertaken in randomly selected replicate quadrats were combined and mean density data were analysed. Seedling survival was calculated from counts of the total number of living seedlings in permanent quadrats at B2 and D2. Seedling growth was calculated as the difference in the number of leaves and nodes counted on individual seedlings of each species in B2 and D2, excluding the seedlings that had died and any new recruits since the last survey. Therefore, all analyses and graphs for seedling growth are only for living species and, as leaves may be shed as well as gained, the difference can be either a negative or positive value. For analysis of seedling growth, species recorded on fewer than 10% of plots from the total dataset were excluded from statistical analyses. For data on leaves, species excluded from analyses were Aegialitis annulata, Avicennia marina, Bruguiera exaristata, Ceriops decandra, Camptostemon schultzii, Excoecaria ovalis and Lumnitzera racemosa. These species typically have a very sparse distribution and high rates of senescence. For data on nodes, one species, Bruguiera exaristata, was excluded from analyses due to Prepared for INPEX Cardno Page 12

23 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 insufficient numbers of seedlings. However, certain species were excluded from node counts as internodes on their stems could not be reliably counted. Nodes were only recorded on Rhizophoraceae species which have clearly discernible nodes. By contrast, Aegiceras corniculatum has indistinct internodes on short stems which are characteristically covered in dense algae Assessment Against Trigger Values Two mangrove health indicators (canopy cover and seedling growth and survival) were defined as triggers in the TARP and net change in these were tested in relation to trigger levels. Net change in canopy cover, seedling survivorship and growth were determined by calculating the difference between Impact and Control treatments for D2 and B2 (data pooled for sites and assemblages). Trigger tests were performed in two steps. Firstly, differences between Control and Impact sites were analysed using standard t-tests for two independent samples; however, to test the assumption of equality of variances, prior F-tests were undertaken and the appropriate t-test selected based on the results (i.e. students t-test, for equal variances; Welch s t-test for unequal variances). If t-tests showed that significant differences were found between Control and Impact sites, the second step of the trigger assessment was undertaken. This step involved doing another t-test with the hypothesised mean difference between Control and Impact sites of the set trigger values. A visual comparison of the actual difference between Control and Impact sites (mean ± 95% CI) to trigger values (± 95% CI calculated from pooled Baseline Phase data) was also made. A trigger was considered to have been exceeded if the difference between Control and Impact sites was statistically significant and if the mean difference did not differ significantly from the set trigger value Fauna Raw data for fauna was entered into a Microsoft Access database and then transferred to Excel, from which appropriate tables were compiled for different analyses (e.g. generation of site by species matrices). Due to the intrinsically high numbers of ants, all observations for ants were listed with an abundance of 1. Raw data were examined to identify records of organisms not representing a taxonomically distinct entity or not identified as a species (e.g. records for immature crab, immature Perisesarma, Uca unidentified etc.). These records were excluded from calculations of site species richness. By contrast, faunal abundance data included immature and unidentified organisms in order to fully represent the density of mangrove invertebrate populations. Summary statistics were calculated in either Excel or MINITAB Release for Windows. Differences in total invertebrate species richness and total invertebrate abundance were tested using a mixed model PERMANOVA (i.e. using the nested design outlined above), and were based on Euclidean distance resemblance matrices. All default PERMANOVA+ software options were used, with the exception of number of permutations (maximum permutations = 9999) (Anderson et al. 2008). Post-hoc permutational t-tests were performed, where required, to aid in the interpretation of significant PERMANOVA results. Assessment of invertebrate community composition was carried out in Primer 6. Sites with a species richness less than two and species recorded on fewer than two sites were excluded from analyses. Species composition was represented as either presence/absence or the raw abundance of each species. Nonmetric multidimensional scaling (nmds) based on a Bray-Curtis dissimilarity index was used to analyse untransformed data and each analysis was run from 50 random restarts. Ordinations were used to examine the data for patterns (where each sample site was described by the species richness and/or abundances of the species present) and to present this information in graphs. Points positioned close together on nmds ordinations represent sites that are very similar in invertebrate species composition, and points that are far apart correspond to very different invertebrate communities. Differences in invertebrate composition were tested using the same mixed model PERMANOVA as described for richness and abundance. The Bray- Curtis dissimilarity index was used along with default PERMANOVA options (except number of permutation = 9999). Post-hoc permutational t-tests were performed, where required, to aid in the interpretation of significant PERMANOVA results. To place D2 fauna results in the context of other Darwin Harbour surveys, the data was compared with Baseline Phase data (B1 and B2 pooled) and with two other invertebrate databases: (1) KMPHD comprising records from Metcalfe (2007); and (2) Weddell comprising records from baseline surveys undertaken by K. Metcalfe for the proposed Weddell development (EcoScience NT, 2012). These surveys used the same field methodology as the Prepared for INPEX Cardno Page 13

24 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 NEMP and were conducted at study sites in the East and Middle Arms of Darwin Harbour between 2000 and Taxonomy of invertebrate fauna species in the earlier two databases was cross-checked against the complete NEMP invertebrate database to incorporate recent taxonomic changes of renamed species and ensure accurate comparison of faunal communities between surveys. The four databases were compiled into one matrix of 666 samples (B1/B2 = 228; D1 = 114, D2 = 114; KMPHD = 138; Weddell = 72) by 304 species, where samples represent study plots in which species from all trap types were pooled. Ordinations (nmds) were done on the combined database in order to assess similarity in invertebrate community composition between the three projects. In addition, analysis of similarity (ANOSIM) was carried out (using a maximum of 999 permutations - the default Primer option) to determine whether there were statistical differences in composition among projects. ANOSIM calculates an R statistic, which is an absolute measure of how separated the groups are on a scale of 0 (indistinguishable) to 1 (all similarities within groups are less than any similarity between groups). Results are best interpreted in relation to the value of R, rather than the associated P value also calculated during ANOSIM, where 0.25 R < 0.50 indicates moderate distinction, and R 0.50 indicates strong compositional distinction (Clarke and Gorley 2001). 2.5 Quality Control Collection of Field Data Field data quality control was carried out as per methods detailed in Section 2.4 of the Mangrove Community Health Monitoring Program Baseline Report (Cardno and EcoScience NT 2012) Laboratory Data Laboratory data quality control was carried out as per methods detailed in Section of the Mangrove Community Health Monitoring Program Baseline Report (Cardno and EcoScience NT 2012) Data Analysis Flora Data Recording seedling growth within permanent seedling plots involved the development of new field methodology and data recording techniques. The only accurate method to document the species, position, leaf and node counts of individual seedlings amongst the often dense tangle of existing tree roots and trunks was to compile a hand drawn diagram of each individual 1 m x 1 m quadrat. To prevent errors in recording both seedling position and leaf and node numbers, data were recorded by the same scientist during all field surveys. Where any confusion in seedling location or plant species occurred within plots, those seedlings were noted and omitted from analyses. All Excel files (raw data) were copied into an EcoScience NT database, with additional backups made onto writeprotected dedicated portable USB storage devices Fauna Data Data for D2 was entered into a series of Microsoft Access databases, building on the platform of data recorded during B1, B2 and D1. Data were later exported to Excel spread sheets for specific data processing and analysis. Raw data entered into the spread sheets were checked both during entry to the database and subsequently by a second scientist prior to analysis and any discrepancies checked against the raw data or master species list for verification. All analytical outputs were saved and checked by a senior environmental scientist and any changes to original analyses were saved as different versions to ensure overwrites did not occur. File management was documented by sequential recording of file names in a flow chart detailing the title and location of all files and the sequence of all analyses performed. All data were regularly backed up to write-protected dedicated portable USB storage devices with duplicate external sources in more than one location. Completed data files were uploaded to Cardno s project database on completion of each survey. Prepared for INPEX Cardno Page 14

25 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 3 Results 3.1 Flora Canopy Cover Similar to the patterns observed during B2, canopy cover in D2 was generally greatest in the Hinterland Margin (92.5% ± 0.7 SE) and Tidal Creek (95.3% ± 0.5 SE) assemblages, intermediate in the Tidal Flat (84.7% ± 1.1 SE), and lowest in the Seaward (78.5% ± 1.6 SE) assemblage (Table 3-1, Figure 3-1). In D2, canopy cover had declined since B2 at most sites in all assemblages, and cover recorded during D2 was generally greater than that recorded in D1. In general, the greatest changes (i.e. losses) in canopy cover since B2 were recorded in the Tidal Flat (-2.5% ± 1.4 SE) and Seaward (-4.0% ± 1.8 SE) assemblages at Impact sites (Table 3-2, Table 3-2). However, despite these differences, the overall percentage change from B2 to D2 between Control and Impact sites was generally small, and similar among assemblages (Table 3-2). Figure 3-1 Mean percentage canopy cover (± SE) in the four assemblages from landward (L) to seaward (R) recorded during D2 at Control and Impact sites Canopy cover was significantly different between Phases for one of the Treatments (p = 0.02) (Appendix D- 1 A). Post-hoc tests showed there was a significant decrease between Phases in the Impact Treatment (p = 0.01) (Appendix B-2 A, Appendix D-1 B) and this is graphed in Appendix B-2 A. Canopy cover was also significantly different between Surveys at some Locations (p < 0.01) (Appendix D-1 A). Post-hoc tests found significant increases (p < 0.05) in the canopy cover between Surveys for one Impact and One Control Site within the Baseline Phase (Appendix D-1 C). As these differences occurred only in the Baseline Phase and in Impact and Control Treatments they were not related to dredging (Appendix B-2 B). Canopy cover was significantly different between Locations at some Assemblages (p < 0.01) (Appendix D-1 A). Post-hoc tests were not done for this term given this interaction was not related to dredging. Prepared for INPEX Cardno Page 15

26 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-1 Summary of mean canopy cover (± SE) recorded during D2 at Control and Impact sites in the four mangrove assemblages Transect Type Site Assemblage No. Assemblage Type Mean cover (%) ±SE Control C1 6 Hinterland Margin Tidal Flat Tidal Creek Seaward C2 6 Hinterland Margin Tidal Flat Tidal Creek Seaward C3 6 Hinterland Margin Tidal Flat Tidal Creek Seaward C4 6 Hinterland Margin Tidal Flat Tidal Creek Seaward NA NA Impact I1 6 Hinterland Margin Tidal Flat Tidal Creek Seaward I2 6 Hinterland Margin Tidal Flat Tidal Creek Seaward I3 6 Hinterland Margin Tidal Flat Tidal Creek Seaward I4 6 Hinterland Margin Tidal Flat Tidal Creek Seaward I5 6 Hinterland Margin Tidal Flat Tidal Creek Seaward I6 6 Hinterland Margin Tidal Flat Tidal Creek Seaward NA NA Prepared for INPEX Cardno Page 16

27 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-2 B2 D2 % change Mean percentage canopy cover (± SE) recorded during B2 and D2 for Control and Impact sites for the four mangrove assemblages Site Type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) % ±SE % ±SE % ±SE % ±SE Control Impact Total Control Impact Total Control (D2-B2) Impact Figure 3-2 Mean percentage change (D2- B2) in canopy cover (± SE) in the four assemblages from landward (L) to seaward (R) Prepared for INPEX Cardno Page 17

28 Quarterly Mangrove Community Health Monitoring Report Dredging Report Level 2 Trigger Assessment Monitoring of canopy cover revealed net change (pooled Impact pooled Control sites) between D2 and B2 was -1.0 % (Appendix B-1 A) demonstrating similarity between Control (-0.9%) and Impact sites (-1.9%). A t-test done on pooled D2 canopy cover data; testing differences between Control and Impact sites found that the -1.0% difference was not statistically significant (p = 0.16) (Appendix D-1 D). The Level 2 trigger for mangrove canopy cover (>30% net change) was not exceeded during D2 (Figure 3-3). Figure 3-3 Mean percentage net change (D2-B2) in canopy cover (± SE) for Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>30% net change) Seedling and Sapling Density and Recruitment Seedling and sapling density recorded at Control and Impact sites in D2 and B2 within each of the four assemblages are summarised in Table 3-3. Information on seedling and sapling species richness is summarised in Appendix B-1 E Seedling Density Patterns in seedling density recorded during D2 were generally similar to those recorded during D1, B1 and B2, with seedling numbers greatest in the Tidal Flat and Seaward assemblages and lowest in the Hinterland Margin and Tidal Creek (Figure 3-4). Similar to results for D1, the most notable declines in seedling density in D2 were recorded in the Seaward assemblage in Control and Impact sites (Table 3-3, Figure 3-5). Although seedling density declined in both Treatments, changes were greater at Impact sites (-9.2 ± 3.3 SE per m 2 ) than at Control sites (-2.9 ± 2.8 SE per m 2 ) (Table 3-3, Figure 3-5). Another notable change in seedling density occurred in the Tidal Flat assemblage at Control sites where it increased by 5.9 ± 2.8 SE per m 2 since B2 (Table 3-3, Figure 3-5). A significant difference in density was found between Phases at particular Locations (p < 0.01) (Appendix D-2 A) but post-hoc tests failed to identify precisely where this occurred (Appendix D-2 B). Plots suggest that there was lower seedling density in the Seaward assemblage during the Dredging Phase but, given this difference was independent of Control and Impact Treatments, this would suggest that it was unrelated to dredging (Appendix B-2 D). Canopy cover was significantly different between Locations at some Assemblages (p<0.01) (Appendix D-2 A). Post-hoc tests were not done for this term given this interaction was not related to dredging. Prepared for INPEX Cardno Page 18

29 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-3 Summary of total mean seedling and sapling densities (per m 2 ± SE) recorded during B2 and D2 at Control and Impact sites, in the four mangrove assemblages. Change in density (D2-B2) is indicated, with a decline denoted by a minus sign (-) Site type Plant type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) Seedling Density SE Density SE Density SE Density SE B2 D2 Change (D2-B2) Control Impact Control Impact Control Impact Sapling Density SE Density SE Density SE Density SE B2 D2 Change (D2-B2) Control Impact Control Impact Control Impact Figure 3-4 Mean seedling density (± SE) in the four assemblages from landward to seaward recorded during D2 at Control and Impact sites Prepared for INPEX Cardno Page 19

30 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-5 Mean percentage change (D2- B2) in seedling density (± SE) in the four assemblages from landward to seaward Sapling Density In D2, sapling densities were small at all sites and in all assemblages, similar to B2. Overall, changes in sapling density were minimal (Table 3-3), a pattern also observed during D1, so data were not presented graphically for this reason. Significant differences in sapling densities were found between Surveys in some Locations (p = 0.03) (Appendix D-2 C). Post-hoc tests found that sapling density varied significantly (p < 0.01) between B1 and B2, at some Control and some Impact sites, but not between D1 and D2 (Appendix B-2 C, Appendix D-2 D). Hence, this was not indicative of an effect of dredging. Sapling density was significantly different between Locations at some Assemblages (p = 0.02) (Appendix D-2 C). Post-hoc tests were not done for this term given this interaction was not related to dredging Seedling and Sapling Richness A total of 11 mangrove seedling species were recorded during the D2 survey at the ten monitoring sites. Species recorded comprised Avicennia marina, Aegiceras corniculatum, Aegialitis annulata, Bruguiera exaristata, Bruguiera parviflora, Camptostemon schultzii, Ceriops australis, Ceriops decandra, Rhizophora stylosa, Lumnitzera racemosa and Xylocarpus moluccensis. In general, relative to B2, seedling species richness recorded during D2 decreased in the Hinterland Margin in Control and Impact Treatments, but increased or did not change in all other assemblages (Appendix B-1 E). Variation among assemblages and between Control and Impact sites was generally similar (Appendix B-1 E). Sapling species richness was consistently small across the intertidal area. Relative to B2, species richness declined in the Tidal Flat at both Control and Impact sites but increased or remained similar in all other assemblages (Appendix B-1 E). Overall, no clear or consistent patterns were observed, and changes in mean species richness were inherently small (< 1 species). Prepared for INPEX Cardno Page 20

31 Quarterly Mangrove Community Health Monitoring Report Dredging Report Seedling Growth and Survival Leaves and Leaf Change In D2, there were more leaves on seedlings in the Control Treatment than in the Impact Treatment (Table 3-4, Figure 3-6). This pattern was consistent with what was observed in D1 and B2 (Cardno and EcoScience NT 2012, 2013). Table 3-4 Summary of mean leaf count and total mean % leaf change (± SE) of seedlings in monitoring plots at Control and Impact sites in the four assemblages during B2 and D2 Site type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) B2 D2 % change (D2-B2) leaves ±SE leaves ±SE leaves ±SE leaves ±SE Control Impact Control Impact Control Impact Figure 3-6 Mean number of leaves (± SE) on seedlings in permanent monitoring plots in the four assemblages from landward to seaward recorded during D2 Relative to B2, the greatest change in leaf counts in D2 occurred in the Control Treatment in the Tidal Flat assemblage (41.7% ± 4.1 SE) (Table 3-4). Overall in D2, leaf counts relative to B2 increased in Control and Impact Treatments and in all assemblages (Table 3-4, Figure 3-7). For all species combined, a significant difference in leaf counts was found from B2 to D2 between Control and Impact Treatments, independent of Assemblage and Location (p < 0.01) (Appendix D-3 A). There were also significant differences among Assemblages (p < 0.01) and among Locations (p < 0.01) (Appendix D-3 A). Post-hoc tests revealed significant differences (p < 0.05) between some of the Control sites (Appendix D-3 B, Appendix B-2 E). Prepared for INPEX Cardno Page 21

32 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Analyses of individual species found no significant differences (p > 0.05) between Control and Impact Treatments; however, significant differences in leaf change from B2 to D2 between some Locations were found for Aegiceras corniculatum (p < 0.01), Rhizophora stylosa (p < 0.01) and Ceriops australis (p < 0.01) seedlings (Appendix D-3 D, E & G). Given that these differences were across treatments they were not indicative of an effect of dredging. No significant differences were recorded for Bruguiera parviflora seedlings (Appendix D-3 F). Figure 3-7 Mean percentage change in the number of leaves (± SE) for seedlings in monitoring plots in the four assemblages from landward to seaward recorded during D Level 2 Trigger Assessment Seedling growth, measured by net percentage change in mean leaf count from B2 to D2 (pooled Impact pooled Control sites) was -4.3%. Percentage change in leaves was similar between Control (34.5 ± 3.1 SE) and Impact (30.2 ± 1.9 SE) treatments when data were pooled for sites and assemblages (Appendix B-1 B). This result was inconsistent with the results of the PERMANOVA; however, a t-test on a hypothesised difference of 50% (i.e. the trigger value) between Control and Impact treatments indicated that the observed difference (-4.3%) was significantly different from 50% (p < 0.01(Appendix D-3 C). The Level 2 trigger for seedling growth (>50% net change) was not exceeded during D2 (Figure 3-8). Prepared for INPEX Cardno Page 22

33 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-8 Mean percentage change (D2-B2) in leaves (± SE) recorded at Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>50% net change) Nodes and Nodal Change Patterns in node counts and nodal change during D2 relative to B2 were similar to results for D1. In D2, mean node counts and percentage nodal change were greatest in the Tidal Creek assemblage in Control (63.6% ± 8.4 SE) and Impact (69.9% ± 3.4 SE) Treatment (Table 3-5, Figure 3-9 and Figure 3-10). Mean node counts and nodal change for the other assemblages were generally similar between Treatments (Table 3-5, Figure 3-9). It should be noted that node count data was not obtained for seedlings in the Seaward assemblage due to the absence of suitable species (i.e. Rhizophoraceae seedlings). Overall, vertical growth occurred in all sites and assemblages and in Control and Impact Treatments and the greatest change in nodes occurred in the Tidal Creek assemblage in both Treatments (Table 3-5, Figure 3-10). Table 3-5 Summary of mean nodes and total mean % nodal change (± SE) of Rhizophoraceae seedlings in monitoring plots at Control and Impact sites recorded during B2 and D2 for the Hinterland margin, Tidal Flat and Tidal Creek assemblages Site type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) B2 D2 % change (D2-B2) nodes ±SE nodes ±SE nodes ±SE Control Impact Control Impact Control Impact Prepared for INPEX Cardno Page 23

34 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-9 Mean nodes (± SE) for Rhizophoraceae seedlings in monitoring plots in the Hinterland Margin, Tidal Flat and Tidal Creek assemblages recorded during D2 Figure 3-10 Mean percentage change in the number of nodes (± SE) for Rhizophoraceae seedlings in monitoring plots in the Hinterland margin, Tidal Flat and Tidal Creek assemblages recorded during D2 For all species combined, a significant difference in the change in number of nodes from B2 to D2 was found between Treatments (p = 0.03) independent of Assemblage or Location and a significant difference was found among Assemblages (p < 0.01) independent of Treatment or Location (Appendix D-3 H, Appendix B- 2 F). Analyses of nodal change for individual species between B2 to D2 found significant differences between Treatments (p = 0.02) and between particular Locations (p = 0.02) for Rhizophora stylosa seedlings in the Tidal Creek assemblage (Appendix D-3 J). Although significant differences were recorded between Control and Impact Treatments, as was also found in D1, mean nodal change was positive for both Treatments and greater in the Impact Treatment (69.9 ± 3.4 SE) than the Control Treatment (63.6 ± 8.4 SE) (Table 3-5). This indicates the observed difference was not due to dredging. Post-hoc tests investigating the changes in Prepared for INPEX Cardno Page 24

35 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Rhizophora stylosa nodes between Locations found significant differences (p = 0.04) between Impact sites I1 and I3 only (Appendix D-3 K). For Bruguiera parviflora seedlings significant differences between some Locations (p = 0.02) were found in the Tidal Creek assemblage (Appendix D-3 L) but these were not related to dredging. No significant changes were recorded for Ceriops australis seedlings (Appendix D-3 M) in the two assemblages where this species occurs (i.e. Tidal Flat and Hinterland Margin) Level 2 Trigger Assessment Measured net change in node counts (pooled Impact pooled Control sites) was -1.3% (Appendix B-1 C). Percentage change in nodes was similar between Control (58.6 ± 3.3 SE) and Impact sites (57.4 ± 2.3 SE) when data were pooled for sites and assemblages (Appendix B-1 C). This result was inconsistent with the results of the PERMANOVA; however, a t-test on a hypothesised difference of 50% (i.e. the trigger value) between Control and Impact treatments indicated that the observed difference (-1.3%) was significantly different from 50% (p < 0.01) (Appendix D-3 I). The Level 2 trigger for seedling growth (>50% net change) based on internode counts was not exceeded during D2 (Figure 3-11). Figure 3-11 Mean percentage net change (D2- B2) for nodes (± SE) at Control and Impact sites (data pooled for all sites and assemblages) in comparison with the Level 2 trigger (>50% net change) Seedling Survival Continued seedling senescence was recorded in all assemblages and at all sites. Patterns in the total mean number of surviving seedlings recorded during D2 was similar to those recorded in D1 (Figure 3-12). Although survival was again lowest at Impact sites in the Hinterland Margin (61.2% ± 5.4 SE) and Seaward (67.0% ± 4.7 SE) assemblages, more seedlings died in Control sites in the Tidal Flat (72.7% ± 6.0 SE) assemblages than at Impact sites (Table 3-6, Figure 3-12). As found in D1, the greatest change in seedling survival was recorded in the Seaward assemblage at Impact sites (Table 3-6, Figure 3-12). Mean survivorship at particular Locations differed significantly amongst the four Assemblages (p < 0.01) but this was unrelated to dredging (Appendix D-3 N). Prepared for INPEX Cardno Page 25

36 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-6 Summary table for total mean survival (± SE) and net survival change (D2-D1) of seedlings in monitoring plots at Control and Impact sites recorded during D2 in the four mangrove assemblages Site type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) % change (D2-B2) % ±SE % ±SE % ±SE % ±SE Control Impact *Survival change is derived from total remaining D2 seedlings minus total remaining B2 seedlings, not percentage seedling survival. Hence percentage B2 seedling survival is not shown. Figure 3-12 Mean % surviving (± SE) seedlings in monitoring plots in the four assemblages from landward to seaward recorded during D Level 2 Trigger Assessment Net change in seedling survival (pooled Impact pooled Control sites) was -4.2% (Appendix B-1 D). Changes in mean percentage survival were similar between Control (77.6% ± 2.8 SE) and Impact (73.4% ± 2.3 SE) sites (Appendix B-1 D). A t-test on a hypothesised difference of 50% (i.e. the trigger value) between Control and Impact treatments indicated that the observed difference (-4.2%) was significantly different from 50 % (p < 0.01) (Appendix D-3 O). The Level 2 trigger for seedling survival (>50% net change) was not exceeded during D2 (Figure 3-13). Prepared for INPEX Cardno Page 26

37 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-13 Mean percentage net change (D2- B2) in seedling survival (± SE) for Control and Impact sites (data pooled for all sites and assemblages) in relation to the Level 2 trigger (>50% net change) Photo-monitoring Photo-monitoring images for B1 and D2 are presented in Appendix E. Images for Impact sites are presented in Appendix E-1 and Control sites in Appendix E-2. Four images are provided from each plot with the date, site, assemblage and direction (i.e. photographer facing toward either corner post 1, 2, 3 or 4) indicated on the plot identification board (when not obscured by vegetation). It is evident from photo-monitoring images that some minor changes in forest structure and physiognomy have occurred during the seven-month period since B1 and B2. The most noticeable are the shedding of branches and attrition of (dead) trees. It appears that these minor changes are largely natural as they were typically observed at both Control and Impact sites. It is also possible, however, that physical disturbance associated with routine visits by the scientific monitoring team may have contributed to some localised damage. This could potentially have caused branch breakage, loss of seedlings and saplings due to accidental trampling and occasional felling of dead or damaged saplings and small trees. Furthermore, a high proportion of Ceriops australis trees are hollowed by Teredinid molluscs (or Shipworms), which may eat out the inside of up to 70% of standing living Ceriops forests. This natural phenomenon substantially weakens these trees leaving them more vulnerable to anthropogenic damage or damage by natural causes (wind-throw, erosion, disease, storm damage). The most pronounced visual changes evident from photo-monitoring during D2 were observed in the Seaward assemblage at Impact site I2 where a number of Aegiceras corniculatum trees have been lost apparently by natural senescence since B1 (Appendix E1, Site I28-1). It is possible these trees were overmature when photographed during B1, or they may have been subject to subsequent erosion. These small trees occur in a relatively exposed position on an open creek bank in the dynamic lower intertidal zone at a location where substantial seedling and sapling mortality was also recorded. However, in general little or no change in community structure, composition, regeneration or general mangrove health was evident from comparison of D2 and B1 images from the other nine monitoring sites. The absence of any discernible changes in physiognomy, species composition or health at impact sites indicates little evidence of impact during the early Dredging Phase of the Project. Prepared for INPEX Cardno Page 27

38 Quarterly Mangrove Community Health Monitoring Report Dredging Report Fauna General Findings Overall, 8,562 faunal records from 249 species were documented during D2 at the ten monitoring sites (Table 3-8 and Appendix C-2, Table C-2 A). Total species richness recorded during D2 (249) was slightly greater than that recorded in D1 (242) but less than the pooled total for B1/B2 (271 species). Similar to previous surveys, the total number of faunal records during D2 was greater at Impact sites (4,873 records from six sites) in comparison to Control sites (3,689 records from four sites) due to greater sampling effort (six sites) in comparison with Control sites (four sites). Total species abundance during D2 (8,562 records) was also greater than that recorded during D1 (7,170) but was less than the pooled total for B1/B2 surveys (8,971). The combined total number of individuals recorded from all surveys to date (B1, B2, D1 and D2) is 24,704 from 345 species (Table 3-8). Based on all four surveys undertaken to date, species richness of invertebrate fauna was dominated by crustaceans (29% of total, comprising 16% decapod crabs and 13% other crustaceans), molluscs (27%) and worm species (23%), which collectively comprised 79% of all species. In terms of the total number of records (frequency), the invertebrate fauna was dominated by crustaceans (40% of total, comprising 30% decapod crabs and 10% other crustaceans), molluscs (26%) and worms (17%), which collectively comprised 83% of all records. A total of 68 mollusc species were recorded during D2, along with 54 worm, 45 crab, 30 other crustacean, 24 ant, 20 fish and 8 other invertebrate species. A complete (cumulative) list of all species recorded to date is provided in Appendix C-2, Tables C-2 B to C-2 H, indicating the Family, taxonomic group and presence of each species at Control and Impact locations New Taxonomic Records Nine new taxonomic records for Darwin Harbour mangrove habitats were obtained during D2 (Table 3-7) comprising four molluscs, four crustaceans and one sponge. To date, fauna surveys for this monitoring project have produced 48 new taxonomic records for mangrove habitats in Darwin Harbour comprising 12 crustaceans, 11 molluscs, 11 worms, 10 ants, 3 fish and 1 sponge. Appendix C-2 A contains a summary table listing the 48 new taxonomic records, indicating the family, taxonomic group and the survey during which it was recorded. The summary table also highlights those species that represent new records for Darwin Harbour and new species for the Northern Territory. Table 3-7 New taxonomic records for species sampled during D2 from Control and Impact sites Species name Family Taxonomic group Notes Gammarid sp. 2 Gammaridea amphipod New DH mangrove record Zehntheria sp. Pilumnidae crab New DH mangrove record Odostomia sp. 4 Pyramidellidae gastropod New DH mangrove record Turbonilla sp. 2 Pyramidellidae gastropod New DH mangrove record Pseudomerelina mahimensis Iravadiidae gastropod New DH mangrove record Cycladicama subquadrata Ungullinidae bivalve New DH mangrove record Cymothoidae sp. 6 Cymothoidae Isopod New DH mangrove record Podocopa sp. Podocopa* shrimp New DH mangrove record Sponge sp. 3 Demospongiae** sponge New DH mangrove record *Subclass **Class Prepared for INPEX Cardno Page 28

39 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-8 Total number of invertebrate species and individuals (in parentheses) for each taxonomic group recorded during B1, B2, D1 and D2 B1 and B2 (pooled) for the four mangrove assemblages at Control and Impact sites. The overall species richness and percentage of records for all surveys to date are also indicated Survey Taxonomic group Total species richness Total individuals B1 & B2 pooled D1 D2 Ants* Decapod crabs Other crustaceans (excl. crabs) Molluscs Worms Other inverts. Control (1,243) 26 (412) 56 (990) 38 (567) 6 (15) 13 (143) 202 3,547 Impact (2,358) 28 (481) 72 (1,101) 51 (734) 6 (24) 16 ( 173) 244 5,425 Control (925) 26 (388) 47 (758) 31 (256) 3 (3) 12 (133) 186 3,040 Impact (1,455) 24 (503) 55 (778) 38 (482) 5 (16) 11 (131) 197 4,130 Overall (2,380) 34 (891) 61 (1,536) 51 (738) 5 (19) 17 (264) 242 7,170 Control (1,237) 20 (690) 49 (1,147) 35 (371) 4 (12) 15 (109) 185 3,689 Impact (1,828) 29 (966) 58 (1,172) 46 (574) 7 (24) 16 (157) 214 4,873 Overall (3,065) 30 (1,656) 68 (2,319) 54 (945) 8 (36) 20 (266) 249 8,562 Overall spp. richness (% total sp. rich.) 39 (11%) 54 (16%) 46 (13%) 92 (27%) 80 (23%) 10 (3%) 24 (7%) ,704 Percentage of all species records 11% 30% 10% 26% 17% 1% 5% * Abundance was not recorded for ants Fish Prepared for INPEX Cardno Page 29

40 Quarterly Mangrove Community Health Monitoring Report Dredging Report Species Richness A summary table of the mean total invertebrate species richness recorded at Control and Impact sites within each of the four main assemblages is presented in Table 3-9. The values represent mean species richness (all taxa) for B1, B2, D1 and D2, calculated from three replicate sampling stations per monitoring plot, averaged across Control and Impact sites. A more detailed summary of mean total invertebrate species richness from assemblages at each site, averaged for B1/B2 (pooled) and D2 is compiled in Appendix C-1 A. Mean total invertebrate species richness recorded during D2 was similar to, or slightly greater than, mean richness recorded during D1 (Table 3-9, Figure 3-14). This pattern was observed at Control and Impact sites, and across most assemblages. Similar to results for B1, B2 and D1, total invertebrate species richness differed amongst the four mangrove assemblages, with richness increasing from landward to seaward during D2 (Figure 3-14,Table 3-9). Mean total invertebrate richness was highest in the Seaward assemblage (33.4 ± 1.4 SE), declined in the Tidal Creek (25.6 ± 1.1 SE) and Tidal Flat (25.7 ± 1.2 SE) assemblages, and lowest in the Hinterland Margin (16.4 ± 0.5 SE). Table 3-9 Mean total invertebrate species richness (± SE) per monitoring site for B1, B2, D1 and D2 for Control and Impact sites in the four mangrove assemblages Survey Type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) B1 B2 D1 D2 mean ±SE mean ±SE mean ±SE mean ±SE Control Impact Control Impact Control Impact Control Impact Total Figure 3-14 Mean total invertebrate species richness (± SE) in the four assemblages from landward (L) to seaward (R) recorded during B1, B2, D1 and D2 Prepared for INPEX Cardno Page 30

41 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 The minimum mean species richness per sampling station during D2 was recorded in the Hinterland Margin at site I5 (12.7 ± 1.3 SE) and the maximum (37.7 ± 3.0 SE) was recorded in the Seaward assemblage at the same site (Appendix C-1 A). Mean species richness in the Hinterland Margin assemblage ranged from 12.7 to 21.6 species during D2 with high similarity between Control (16.9 ± 1.2 SE) and Impact Treatments (16.1 ± 1.0 SE). Variability within the Hinterland Margin was low, with standard error ranging from 0.3 to 2.8 (Appendix C-1 A). In the Tidal Flat assemblage, means ranged from 14.0 to 33.7 and were higher in Control sites (28.5 ± 1.8 SE) than Impact sites (23.9 ± 1.6 SE). Standard error ranged from 1.2 to 6.0 in this assemblage. The site with the highest mean for the Tidal Flat was C1 (33.7 ± 3.7 SE); the lowest mean (14.0 ± 1.5 SE) was recorded at site I5. In the Tidal Creek assemblage, mean species richness ranged from 21.3 to Although means were similar at Control and Impact sites in the Tidal Creek, they were slightly higher at Impact sites (26.2 ± 1.6 SE) than Control sites (24.7 ± 1.5 SE) and standard errors ranged from 0.3 to 7.3. Highest mean species richness was recorded in the Seaward assemblage where means ranged from 30.7 to 37.7 per sampling station and were slightly higher at Impact sites (34.4 ± 1.6 SE) than Control sites (31.8 ± 2.8 SE). The standard error ranged from 1.4 to 7.0 species in the Seaward assemblage. Appendix C-3 presents graphs of mean invertebrate species richness values for each of the main taxonomic groups (ants, crabs, other crustaceans, molluscs, worms and other invertebrates) for B1, B2, D1 and D2 at Control and Impact sites within the four assemblages. Analyses revealed that mean species richness varied between some Locations during the different Surveys (p = 0.02). Species richness was also significantly different between Baseline (i.e. B1 & B2) and Dredging (i.e. D1 & D2) Phases (p < 0.05) depending on the Assemblages and Site (Appendix D-4 A). Post-hoc pairwise t-tests found that total invertebrate species richness varied between Surveys only in the Baseline Phase, indicating local temporal variation rather than an effect of dredging (Appendix D-4 B). Post-hoc tests failed to pinpoint when the species richness varied for each combination of Assemblages, Locations and Phases (Appendix D-4 C, Appendix D-4 D). Importantly, analyses indicated there were no significant differences (p>0.05) for species richness between Control and Impact sites as the same pattern (significant increase in species diversity from Baseline Phase to Dredging Phase) was recorded at both Control and Impact sites (Appendix D-4 D) Abundance A summary of results for total invertebrate abundance recorded at Control and Impact sites within each of the four assemblages is presented in Table The values represent mean abundance (all species) for B1, B2, D1 and D2, calculated from three replicate sampling stations per monitoring plot, averaged across Control and Impact sites. A more detailed summary of means for total invertebrate abundance from assemblages at each site, averaged for B1/B2 (pooled) and D2 is compiled in Appendix C-1 B. The minimum mean abundance per sampling station (39.3 ± 7.6 SE) was recorded at site I5 in the Hinterland Margin (Appendix C-1 B) and the maximum abundance at site C1 in the Tidal Flat (165.3 ± 43.5 SE). Prepared for INPEX Cardno Page 31

42 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Table 3-10 Mean total invertebrate abundance (± SE) per sampling station for B1, B2, D1 and D2 for Control and Impact sites in the four mangrove assemblages Survey Type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) B1 B2 D1 D2 mean ±SE mean ±SE mean ±SE mean ±SE Control Impact Control Impact Control Impact Total Control Impact Total Figure 3-15 shows total invertebrate abundance per sampling station in the four mangrove assemblages from landward to seaward (left to right) for B1, B2, D1 and D2. Patterns in mean abundance were generally similar to those observed for mean species richness. Total invertebrate abundance differed amongst the four assemblages and was consistently higher during D2 than during B1/B2 in most assemblages. During D2, total invertebrate abundance was highest in the Seaward (96.4 ± 7.9 SE) and Tidal Flat assemblages (75.4 ± 7.4 SE) with lower abundance in the Hinterland Margin (66.6 ± 6.6 SE) assemblage. The lowest mean abundance was recorded in the Tidal Creek assemblage (57.1 ± 6.7 SE). For Control sites, abundance was greater in the Hinterland Margin than the Tidal Creek, but for Impact sites, this trend was reversed (Table 3-9, Figure 3-15). Figure 3-15 Mean total invertebrate abundance (± SE) in the four main assemblages from landward (L) to seaward (R) recorded during B1, B2, D1 and D2 Analyses of total invertebrate abundance during D2 revealed similar results to those for species richness. Species abundance was significantly different between Phases for different Locations in some Assemblages Prepared for INPEX Cardno Page 32

43 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 (p < 0.01) (Appendix D-4 E). Differences between B1/B2 (pre-dredging) and D1/D2 (dredging phase) were not as evident for total invertebrate abundance as for species richness. Post-hoc pairwise t-tests failed to pin-point where these differences occurred (Appendix D-4 F), and the lack of any consistent pattern between Baseline and Dredging Phases is shown by the graph in Appendix D-4 G. Comparisons of means and variance of total invertebrate abundance for the four assemblages indicated that during D2, mean invertebrate abundance ranged from 39.3 to in the Hinterland Margin. As noted above, means were higher in Hinterland Margin Control sites (86.4 ± 13.4 SE) than at Impact sites (53.4 ± 4.5 SE) and overall the standard error ranged from 4.0 to 51.9 animals per sampling station. For the Tidal Flat assemblage, mean invertebrate abundance ranged from 48.3 to and standard error ranged from 4.4 to In the Tidal Creek, mean invertebrate abundance ranged from 39.7 to 77.3 and standard error (SE) ranged from 3.3 to Mean abundance was similar, but slightly higher in Impact sites (58.8 ± 5.1 SE) than Control sites (54.5 ± 5.1 SE). In the Seaward assemblage, mean invertebrate abundance ranged from 63.3 to with SE ranging from 4.3 to Means were substantially higher at Impact sites (107.3 ± 10.6 SE) than Control sites (78.2 ± 9.3 SE). Plots of mean invertebrate abundance for each of the taxonomic groups (ants, crabs, other crustaceans, molluscs, worms and other invertebrates) for B1, B2, D1 and D2 surveys for Control and Impact sites within the four assemblages can be found in Appendix C Community Composition Ordinations based on the presence/absence of all invertebrate species within monitoring plots in the four assemblages showed little distinction between Control and Impact sites (Figure 3-16). This is indicated on the ordination by the scattered distribution of all points, with no clear clustering of either Control sites (grey) or Impact sites (blue). Similarly, there was no evidence of distinction between B1 and B2 (indicated on the ordination by upward and downward facing triangles respectively), D1 (indicated by the open circles), and D2 (indicated by closed circles) (Figure 3-16). Figure 3-16 Ordination of sampling stations at Control (grey) and Impact sites during B1, B2, D1 and D2 based on presence/absence of invertebrate species. Data were pooled for all sampling methods per station in each of the four assemblages Analyses revealed significant differences in species composition between Phases (p = 0.02). Evidence of localized differences in community composition between Surveys within each Phase and Assemblage were also detected (p < 0.05) (Appendix D-4 H). Post-hoc tests failed to locate exactly where these differences Prepared for INPEX Cardno Page 33

44 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 occurred (Appendix D-4 I). Importantly, there was no significant distinction (p>0.05) between Control and Impact sites. In general, compositional change between Phases was in accordance with the observed increases in species richness and abundance from Baseline (i.e. B1 & B2) to Dredging (i.e. D1 & D2), and the change from dry season to wet season, described in Sections and The clear distinction between faunal abundance in different assemblages observed during previous surveys was still evident with the inclusion of D2 data (Figure 3-17) with points representing sites in different assemblages clearly grouped into separate sections of the ordination. This trend was also characteristic of patterns recorded in previous mangrove surveys in Darwin Harbour (EcoScience NT 2012; Metcalfe 2007, 2010). When the same ordination was re-displayed to examine season (Figure 3-18), no clear distinction between mean invertebrate abundance during wet and dry season sampling was evident. A slight separation of wet and dry season sampling stations is suggested in the two most landward assemblages (Hinterland Margin and Tidal Flat). This potential trend will be analysed after the addition of more data for the D3 report. Figure 3-17 Ordination of sampling stations sampled during B1, B2, D1 and D2 in the four assemblages based on the presence/absence of invertebrate species Data were pooled for all sampling methods used per station Community composition was also examined for the three main taxonomic groups: crustaceans, molluscs and worms, and similar trends were noted in these nmds ordinations (Appendix D-2 E, D-2 F and D-2 G). There was no evidence of distinction between sites on the basis of treatment (Control vs. Impact) or survey period (B1, B2, D1 and D2). Prepared for INPEX Cardno Page 34

45 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Figure 3-18 Ordination of sampling stations sampled during dry and wet season B1, B2, D1 and D2 based on the presence/absence of invertebrate species Data were pooled for each sampling method for dry and wet season surveys To place the invertebrate fauna data collected during B1, B2, D1 and D2 into the context of Darwin Harbour, the data were analysed with two other data sets obtained using the same methodology at other sites in the East and Middle Arms of Darwin Harbour between 2000 and Ordinations of the combined database based on abundance (Figure 3-19) showed some minor distinction between the doctoral studies (KMPHD) and the Weddell project invertebrate communities; however, B1/B2, D1 and D2 did not appear to be clearly distinct from the other two project databases, or from each other. Indeed, ANOSIM results for pair-wise comparisons were R = 0.11, for D2 versus Weddell, and R = 0.20, for D2 versus KMPHD, indicating no significant differences. Figure 3-19 Ordination plot of invertebrate species based on abundance for B1/B2 (blue squares), D1 (green squares), D2 (pink squares), KMPHD surveys (grey circles) and Weddell baseline surveys (black triangles) Prepared for INPEX Cardno Page 35

46 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 4 Discussion 4.1 Mangrove Community Health Flora Canopy Cover Canopy cover since B1/B2 had decreased slightly at both Control (-0.9% ± 0.5 SE) and Impact sites (-1.9% ± 0.6 SE) and this difference between treatments was statistically significant between Baseline and Dredging Phases. Despite this, the net change in overall canopy cover (pooled Impact pooled Control sites) during D2 (-1.0%) was well below the trigger level of 30%. The small overall difference in canopy cover was mainly due to differences between treatments in the Seaward assemblage and Tidal Flat. A decline in canopy cover was detected between Baseline and Dredging Phases but given the small magnitude of the change it is considered to have no ecological significance. The change is likely to be natural or associated with the inherently high variability associated with measurement of canopy cover in the Seaward and Tidal Flat assemblages. Future surveys will determine if there are trends (declines) in canopy cover and if so, whether these are due to natural factors or from dredging. The Intertidal Sedimentation Monitoring Program has shown that sedimentation in the Seaward assemblage has generally increased since B2 at both Impact and Control sites (Cardno 2013b). Net sedimentation based on stake measurements in the Seaward assemblage for D2 (February 2013) was 6.0 ± 1.3 mm SE for pooled Impact sites and 4.0 ± 1.1 mm SE for pooled Control sites (Cardno 2013b). However, given the large natural variability in sedimentation in the Seaward assemblage and that these changes were less than the trigger value (50 mm), they are more likely to be seasonal (natural) and are unlikely to have a detrimental impact on canopy cover. It should also be noted that the Northern Territory wet season up to the end of February was hot and dry with many locations recording the lowest wet season rainfall on record to that point in the season (BOM 2013). The northern region of the Northern Territory experienced unseasonably dry conditions throughout February, following a month of below average rainfall. The unusually low rainfall may have affected canopy cover in some assemblages. Sonneratia alba trees are the dominant canopy tree in the Seaward assemblage, and are characteristically large, spreading trees that form a woodland to open woodland community with numerous canopy gaps. Variability of canopy cover data recorded in this assemblage has been noted in both the D1 and Baseline Phase reports (Cardno and EcoScience, 2012; 2013) and appears to be the primary reason for the small changes in canopy cover observed in D Seedling and Sapling Density and Recruitment Similar to D1, seedling density declined again in the Seaward assemblage, particularly in the Impact sites. As found in D1, sapling density was inherently low at all sites and in all assemblages, and changes in density were again minimal. Aegiceras corniculatum is the dominant seedling species in the Seaward assemblage and fruit production is from December to March (Wightmann 2006). The gradual senescence of seedlings observed since mid is likely to be a natural phenomenon or annual trend which may soon be reversed with by seedling recruitment during Other explanations for continued reductions in seedling density within the Seaward assemblage lie in the fact that this assemblage is the lowest community in the intertidal zone, meaning the effects of erosion from seasonal wave action (e.g. wet season storms) and freshwater runoff (drain scouring) may be more pronounced. Presumably these factors, either singly or in combination, contribute to their removal by erosion and scour, and hence to the sustained decline in seedling density Seedling Growth and Survival Monitoring of seedling survival and growth indicated that net change in these indicators did not approach Level 2 trigger levels (>50% net change in seedling survivorship and growth). Change in these indicators was well below trigger levels, with seedling growth (pooled Impact pooled Control sites) at -4.3% based on Prepared for INPEX Cardno Page 36

47 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 leaf counts and -1.3% based on node counts, and seedling survival (pooled Impact pooled Control sites) during D2 of -4.2%. Similar to patterns observed in D1, leaf growth was positive for Control and Impact sites (i.e. all plants grew new leaves). However, during D2 it was evident that in all four assemblages the Control sites grew more leaves than the Impact sites, indicated by the change in the number of leaves. Seedlings in all assemblages at Control sites had a consistently greater number of leaves, and it was evident from D2 results that seedlings with greater initial leaf counts grew more leaves than smaller plants. It follows that, as Control sites (7.9 ± 0.4 SE) had a greater total mean number of leaves than Impact sites (5.4 ± 0.1 SE), this may have contributed to the significant difference between Control and Impact sites in the change in number of leaves from B2 to D2. This pattern was evident for all species combined. Similar results were found during D1, where higher leaf growth appears to be associated with higher densities of mature seedlings. Similar to D1, increased nodal growth (i.e. vertical growth) occurred in all assemblages and in Control and Impact sites. A significant difference was found in the change in nodes between Control and Impact sites between assemblages for all species combined, and for R. stylosa seedlings in the Tidal Creek assemblage. Despite the differences in nodal growth between Control and Impact sites, changes were again small, and the growth observed for both treatments was positive. The fact that seedlings in Control sites had greater initial total leaf counts and grew more leaves and nodes than plants at Impact sites suggests that seedlings in Control sites were not only larger but better established. Seedling survivorship indicated that continued senescence occurred in all assemblages in both Control and Impact sites. Patterns in survival were similar to both B2 and D1, with mean survival of seedlings in the Hinterland Margin and Seaward assemblages at Impact sites still lower than Control sites. However, more seedlings were lost in Control sites in the Tidal Flat and Tidal Creek assemblages than at Impact sites. As no clear or consistent trends in survivorship were evident, continued senescence of seedlings in all assemblages is likely to be a natural phenomenon reflecting localized conditions. Changes in seedling growth and survival during D2 showed that plants grew more leaves and nodes, and that senescence continued in most sites and in all assemblages. Changes in growth of this nature were anticipated as increased wet season rainfall probably alleviated water stress, facilitating increased plant growth. Increased freshwater inflow during the wet season also likely reduced soil-salt concentrations within sediments, lowering plant stress, further contributing to increased plant growth rates. Despite increases in rainfall, continued senescence of seedlings was observed at most sites. Continued mortality of seedlings in monitoring plots appears to reflect biotic and abiotic factors such as effects of competition and unsuitability of micro-habitats for successful establishment during the post-recruitment period. In summary, leaf and nodal growth and seedling senescence continued to increase in all sites and assemblages, and although some localised differences in seedling growth and survival were evident among sites and assemblages, no evidence of impacts from dredging were found due to the absence of any clear patterns between Control and Impact sites Photo-monitoring Photo-monitoring images provide a rapid and convenient technique to track changes in physiognomy from the pre-impact phase, through the dredging period and up to the end of the construction phase. Changes in forest structure and composition can be observed through photo-monitoring, even when a statistically significant impact on flora and/or fauna is not detectable. To date, no changes in community structure or composition are evident from comparison of B1 and D2 photo-monitoring images that suggest any impacts associated with dredging. 4.2 Mangrove Community Health Fauna Species Richness and Abundance The 249 species recorded during D2 was similar to that recorded for D1 surveys (242 species). However, it was less than the tally of 271 species for both B1 and B2 surveys combined. The latter reflects the increased sampling effort involved in conducting two surveys (40 field days) compared with D2 alone (20 field days). Overall species richness was similar or slightly higher per plot, and increased in all four assemblages during D2. As found in D1, increases in species richness during D2 appear to be due to Prepared for INPEX Cardno Page 37

48 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 seasonal changes since the June-August period. In particular, increased rainfall (and hence soil moisture) combined with greater tidal inundation of the landward assemblages created more favourable habitat opportunities for a greater variety of organisms of marine origin. The total of 345 species recorded from the ten monitoring sites during B1, B2 D1 and D2 appears representative of mangrove dependent fauna in Darwin Harbour as reported in Metcalfe (2007) and EcoScience NT (2012). The proportion of different taxonomic groups sampled during D2 (30% crustaceans, 27% molluscs and 22% worms) was also characteristic of Darwin Harbour mangrove invertebrate fauna (Metcalfe 2010). Mangrove community health monitoring surveys to date have documented a substantial number of new taxonomic records for Darwin Harbour (48 species to date) and several new species records for the NT and for Australia. Nine new records for species in mangrove habitats of Darwin Harbour were recorded during D2. Close consistency between Control and Impact sites was demonstrated by summary statistics for fauna surveys during D2. Pooled mean species richness for Control sites (25.0 ± 1.2 SE) and Impact sites (24.7 ± 1.0 SE) was very similar, but there were differences in richness for some assemblages at some locations between dredging phases. The relative increase in richness was less at Impact sites, particularly in the Tidal Flat assemblage, and future surveys will clarify whether this is a natural phenomenon or whether there are any consistent patterns which may be associated with sedimentation impacts related to dredging. Increases in faunal richness and abundance during D2 were evident across all assemblages and appear to be associated with seasonal changes (e.g. increased freshwater) and potentially also juvenile recruitment (in particular, large numbers of immature crabs were recorded during D2 fauna surveys), as they were observed at both Control and Impact sites. To date, Baseline Phase surveys have been conducted during the dry season and Dredging surveys were conducted in the wet season. Other studies conducted using the same methodology in Darwin Harbour (Metcalfe, 2007; EcoScience 2010) have noted similar seasonal patterns with consistently higher species richness and abundance during the wet season, with effects most pronounced in the two landward assemblages Community Composition Monitoring of changes in faunal community composition is an important component of mangrove health due to the very small size and degree of specialisation of the invertebrate animals sampled. The majority of mangrove invertebrates either live within or feed upon the top layer of sediment (approximately 5 cm) and as they are of a relatively small size ( 1-30 mm) they are characteristically dependent upon and have direct dietary interaction with surface sediments (Hsieh 1995). Therefore, changes in faunal micro-habitat, including sediment type and particle size, may facilitate or encourage, displace, or exclude existing fauna (Metcalfe and Glasby 2008). Similar to D1 findings, species composition based on presence/absence (all species) data showed little distinction between Control and Impact sites and between B1/B2 and D2. In accordance with patterns established during previous studies in mangroves of Darwin Harbour (Metcalfe 2007; EcoScience NT 2010, 2012), clear distinctions were observed between the four different assemblages. Furthermore, ordinations produced using invertebrate data from previous Darwin Harbour surveys and the D2 data presented in this report demonstrated that community composition and abundance was similar to that recorded during other surveys in the Darwin Harbour region. Statistical analyses also indicated that the faunal composition of assemblages at locations differed between surveys (within phases) but further analyses could not pinpoint at which locations significant differences occurred. There were also differences between the Baseline and Dredging Phases across all locations and treatments. The observed differences in composition between the Baseline and Dredging Phases may be a seasonal or other widespread temporal effect (i.e. influencing all sites and assemblages). Indeed, changed environmental conditions during the wet season create habitat opportunities for fish, shrimps and worms in the two landward assemblages that are not available to these organisms during the dry season. Furthermore, the pronounced increases in diversity and abundance of fauna from Baseline to Dredging Phases appears to be seasonal and reflect seasonal changes in population structure (many species breed during the wet season) and environmental conditions. The results for fauna do not indicate any impact associated with increased sedimentation from dredging. Prepared for INPEX Cardno Page 38

49 Quarterly Mangrove Community Health Monitoring Report Dredging Report Introduced Species During D1, a single introduced ant species (Pheidole megacephala) was recorded at site I2 (Bleesers Creek). Careful resampling of this site during the D2 survey failed to produce further specimens of Pheidole megacephala. Therefore, the presence of this species at site I2 (Bleesers Creek) was considered a contagion rather than evidence of an established colony (A. Andersen, pers. comm.). Indeed, a single ant may have been transported to the site by the research team, particularly given the fiercely opportunistic tendencies of this ant species. Continued monitoring of ants at site I2 (Bleesers Creek) will be continued as part of routine quarterly monitoring of mangrove health during the dredging phase. This will allow the presence (or absence) of P. megacephala at this site to be established during future surveys. Prepared for INPEX Cardno Page 39

50 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 5 Conclusions There were no exceedances of trigger levels during the D2 survey with results for all indicators well below trigger levels. During D2, a -1.0 % change in canopy cover was recorded. Recorded change in seedling growth was -4.3% based on leaf counts, -1.3 % based on node counts and -4.2% based on change in seedling survival. The reactive monitoring indicators (canopy cover, seedling growth and survival) provide appropriate data to allow clear and timely determination of trigger levels and are capable of detecting a >30% net change in canopy cover and a >50% net change in seedling survivorship and growth between Impact and Control sites during future monitoring. Although there was a decline in canopy cover in the Impact treatment, the magnitude of change was small, due to variability of canopy cover in the Seaward assemblage, and as such ecologically insignificant. Monitoring of seedling growth through leaf and node counts revealed increased growth occurred at both Control and Impact sites. Seedling survival continued to decline at all sites and in all assemblages. Characteristic of spatial variation within mangrove ecosystems, significant differences in flora indicators were detected between assemblages. The significant variations in environmental and ecological conditions from the dry to the wet season in Darwin Harbour and the top end of the Northern Territory were reflected in the results of this survey. Quarterly monitoring of mangrove invertebrate fauna during D2 revealed an overall increase in faunal diversity and abundance, but there were differences the Baseline and Dredging Phases in the relative change in species richness, abundance and composition at some locations in some assemblages. Most of these changes are likely to be associated with the pronounced seasonal changes during the eight month period since the Baseline Phase. In summary, monitoring results adequately meet the overall objectives of the Mangrove Community Health Monitoring Program and demonstrate that no triggers were exceeded during the D2 survey period. Prepared for INPEX Cardno Page 40

51 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 6 Acknowledgements This report was written by Dr Kristin Metcalfe, Adam Bourke and Dr Kerry Beggs and reviewed by Dr Peggy O Donnell, Dr Craig Blount and Joanna Lamb. Data processing and presentation was done by Adam Bourke and the statistical analyses for flora and invertebrate fauna were done by Dr Kerry Beggs Field work was undertaken by Kristin Metcalfe, Adam Bourke, Patrick Maher, Carmen Walker and Ivon Sebastian. Specialist input for invertebrate taxonomy was provided by Professor Alan Andersen, Magen Pettit (CSIRO), Dr Richard Willan, Dr Michael Hammer and Dr Chris Glasby (MAGNT) and Peter Davie (Queensland Museum). Jo Buckee and Chris Holloway provided technical support and management of the Project. HSE support in Darwin was facilitated by Todd Sinclair and Erica Griffiths was Project safety officer. Prepared for INPEX Cardno Page 41

52 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 7 References Anderson, M.J., Gorley, R.N. and Clarke, K.R. (2008). PERMANOVA+ for Primer: Guide to Software and Statistical Methods. Primer-E Ltd, Plymouth. Bilyard, G. R. (1987). The value of benthic infauna in marine pollution monitoring studies. Marine Pollution Bulletin 18: Brocklehurst, P. and Edmeades, B. (1996). The mangrove communities of Darwin Harbour. Technical Memorandum No.R96/9. Resource Capability Assessment Branch, Department of Lands, Planning and Environment, Darwin, Northern Territory. BOM (2013) Bureau of Meteorology Website accessed April Cardno (2012). Ichthys Project: Nearshore Environmental Monitoring Plan. Prepared for INPEX August Cardno (2013a). Mangrove Community Health Remote Sensing Baseline Report. Ichthys Project Nearshore Environmental Monitoring Program. Report to INPEX. L384-AW-REP-10015, February Cardno (2013b). Quarterly Intertidal Sedimentation Dredging Report 2. Ichthys Project Nearshore Environmental Monitoring Program. Report to INPEX. L384-AW-REP-10016, February Cardno and EcoScience NT (2012). Mangrove Community Health Monitoring Program Baseline Report. Ichthys Project Nearshore Environmental Monitoring Program. Report to INPEX. L384-AW-REP October pp Cardno and EcoScience NT (2013). Mangrove Community Health Monitoring Program Dredging Report 1. Ichthys Project Nearshore Environmental Monitoring Program. Report to INPEX. L384-AW-REP October pp Clarke, K. R. and Gorley, R. N. (2001). PRIMER v5: User Manual/Tutorial. Plymouth Routines in Multivariate Ecological Research. PRIMER-E Ltd, Plymouth Marine Laboratories, Plymouth, UK. Clarke, K R and Warwick, R M. (1994). Change in Marine Communities. An Approach to Statistical Analysis and Interpretation. Plymouth Marine Laboratory, UK. Clarke, P.J. and Allaway, W.G. (1993). The regeneration niche of the grey mangrove (Avicennia marina): effects of salinity, light and sediment factors on establishment and survival in the field. Oecologia 93: CSIRO (2012). Ants Down Under, viewed 23 December 2012, < Duke, N.C., Zuleika, S. and Pinzon, M. (1992). Aging Rhizophora seedlings from leaf scar nodes: A technique for studying recruitment and growth in mangrove forests. Biotropica 24 Part A: pp Duke, N.C. (2006). Australia s Mangroves. The authoritative guide to Australia s mangroves plants. University of Queensland, Brisbane. EcoScience NT (2010) Darwin LNG Plant. Mangrove Monitoring Program - Mangrove Invertebrate Fauna. Report prepared for URS Australia and Conoco Phillips Pty Ltd by EcoScience, November pp EcoScience NT (2012.) Darwin - Weddell Baseline Environmental Studies - Mangrove Fauna. Report prepared for Northern Territory Government, Department of Lands and Planning, Land Development & Infrastructure. September 2012, 61 pp. Ellison, J.C. (1998). Impacts of sediment burial on mangroves. Marine Pollution Bulletin 37: Ellison, J. C (2006). Mangrove Palaeoenvironmental Response to Climate Change. In Gilman, E. editor (2006). Proceedings of the Symposium on Mangrove Responses to Relative Sea-Level Rise and Other Climate Change Effects, 13 July Catchments to Coast. The Society of Wetland Scientists 27th International Conference, 9-14 July 2006, Cairns Convention Centre, Cairns, Australia. Published by the Western Pacific Regional Fishery Management Council, Honolulu, USA. Ellison, J.C. (2007). Manual for the monitoring of mangroves in the Pacific Islands Region - Monitoring Changes in Mangrove Condition Report to the Secretariat of the Pacific Regional Environment Program, Apia, Samoa. Draft April Ellison, J.C. (2012). Climate Change Vulnerability Assessment and Adaptation Planning for Mangrove Systems. WWF Washington, DC: World Wildlife Fund (WWF). Ellison, A.M., Farnsworth, E.J. (1993). Seedling survivorship, growth and response to disturbance in Belizean mangal. American Journal of Botany 80: Hsieh, H. L. (1995). Spatial and temporal patterns of polychaete communities in a subtropical mangrove swamp - influences of sediment and microhabitat. Marine Ecology Progress Series 127: Hoffman, B. D., A. N. Andersen, G. J. E. Hill (1999). Impact of an introduced ant on native rain forest invertebrates: Pheidole megacephala in monsoonal Australia. Oecologia 120: Prepared for INPEX Cardno Page 42

53 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 INPEX (2011). Ichthys Gas Field Development Project. Draft Environmental Impact Statement. INPEX (2012). Dredging and Spoil Disposal Management Plan East Arm. Ichthys Project Company document No C075-AH-PLN- 0028, Rev August McGuinness, K. A. (1997). Dispersal, establishment and survival of Ceriops tagal propagules in a north Australian mangrove forest. Oecologia 109: McGuinness, K.A. (2003). The mangrove forests of Darwin Harbour: a review of research on the flora and invertebrate fauna. Conference Proceedings: Darwin Harbour Region: Current Knowledge and Future Needs Metcalfe, K. (2007). The Biological Diversity, Recovery from Disturbance and Rehabilitation of Mangroves, Darwin Harbour, NT. Charles Darwin University, PhD thesis: Darwin. (Available on-line at Metcalfe, K. (2010). Mangrove Invertebrate Fauna. Darwin LNG Project Mangrove Monitoring Program, 2010 Report. Prepared for ConocoPhillips Australia Pty Ltd and URS Australia by EcoScience NT. October Metcalfe, K. and Crawford, J. (2007). Darwin LNG Plant, Mangrove Monitoring Program. Mangrove Flora and Soils. Report prepared for ConocoPhillips. April 2007, 58pp. Metcalfe, K.N. and Glasby, C.J. (2008). Diversity of Polychaeta (Annelida) and other worm taxa in mangrove habitats of Darwin Harbour, northern Australia. Journal of Sea Research 59: Moverley, J. (2000). Estuarine health assessment using benthic macrofauna. Rivers for the Future. Museum of Victoria: 1-4. Ode, P. (2007). Standard Operating Procedures for Collecting Benthic Macroinvertebrate Samples and Associated Physical and Chemical Data for Ambient Bio assessments in California. State Water Resources Control Board, Surface Water Ambient Monitoring Program. 48pp. O Grady, A. P., McGuinness, K. A. and Eamus, D (1996). The abundance and growth of Avicennia marina and Rhizophora stylosa in the low shore of Darwin Harbour, Northern Territory. Australian Journal of Ecology 21: Smith, T. J. (1987). Effects of light and intertidal position on seedling survival and growth in tropical tidal forests. Journal of Experimental Marine Biology and Ecology 110: Stickler, G.S. (1959). Use of the densitometer to estimate density of forest canopy on permanent sample plots. US Forestry Service 180 5pp. Terrados, J., Thampanya, U., Srichai, N., Keowvongsri, P., Geertz-Hansen, O., Boromthanarat, S., Panapitukkul, N., Duarte, C.M. (1997). The effect of increased sediment accretion on the survival and growth of Rhizophora apiculata seedlings. Estuarine Coastal and Shelf Sciences 45: Thampanya, U., Vermaat, J.E. and Terrados, J. (2002). The effect of increasing sediment accretion on the seedlings of three common Thai mangrove species. Aquatic Botany 74: Wightmann, G. (2006). Mangroves of the Northern Territory, Australia. Identification and Traditional Use. Northern Territory Botanical Bulletin No. 3. Department of Natural Resources, Environment and the Arts and Greening Australia. 168pp. Prepared for INPEX Cardno Page 43

54 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Ichthys Nearshore Environmental Monitoring Program Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 L384-AW-REP APPENDIX A METHODS DETAILS Prepared for INPEX Page A-1

55 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Appendix A-1 Monitoring Schedule A-1 A: Dredging Survey 2a, 24 January 2013 to 2 February 2013 Site Number Site Name Date (2013) Tasks I1 Bayview 24-Jan Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I1 Bayview 25-Jan Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. C3 Middle Arm 26-Jan Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. C3 Middle Arm 27-Jan Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. I5 Eliz River- Creek 28-Jan Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I5 Eliz River- Creek 29-Jan Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. I2 Bleesers Creek 30-Jan Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I2 Bleesers Creek 31-Jan Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. C4 Blackmore Boatramp 1-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. C4 Blackmore Boatramp 2-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. Prepared for INPEX Cardno Page 47

56 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Appendix A-1 Monitoring Schedule A-1 B: Dredging Survey 2b, 8 to 18 February 2013 Site Number Site Name Date (2013) Tasks I4 Blaydin Point 8-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I4 Blaydin Point 9-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. C2 Channel Is 10-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. C2 Channel Is 11-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. I3 East Arm Boat ramp 12-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I3 East Arm Boat ramp 13-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. I6 Upstream Eliz River 14-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. I6 Upstream Eliz River 15-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. C1 Woods Inlet 16-Feb Sample invertebrate fauna (install pitfall traps and anoxic mats). Measure seedling growth and survival. Photo-monitoring. Sample quadrat fauna. C1 Woods Inlet 17-Feb Check and retrieve pitfall traps and anoxic mats. Densiometer readings. Seedling recruitment. Complete fauna sampling in quadrats. C1 Woods Inlet 18-Feb Pack up and return to Darwin. Demobilisation. Prepared for INPEX Cardno Page 48

57 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Appendix A-2 GPS Co-ordinates GPS Co-ordinates for 20 m x 20 m plots monitored in mangrove community health monitoring program indicating position of corner posts (1 to 4) and centre post (C) N.B. Zone refers to the assemblage numbering in Figure 2.2 Location, Zone & Station Number Station Code Easting Northing CONTROL SITES Site C1 1 S020_C1_Z2_ S020_C1_Z2_ S020_C1_Z2_ S020_C1_Z2_ C S020_C1_Z2_C S020_C1_Z4_ S020_C1_Z4_ S020_C1_Z4_ S020_C1_Z4_ C S020_C1_Z4_C S020_C1_Z6_ S020_C1_Z6_ S020_C1_Z6_ S020_C1_Z6_ C S020_C1_Z6_C S020_C1_Z8_ S020_C1_Z8_ S020_C1_Z8_ S020_C1_Z8_ C S020_C1_Z8_C Site C2 1 S020_C2_Z2_ S020_C2_Z2_ S020_C2_Z2_ S020_C2_Z2_ C S020_C2_Z2_C S020_C2_Z4_ S020_C2_Z4_ S020_C2_Z4_ S020_C2_Z4_ C S020_C2_Z4_C S020_C2_Z6_ S020_C2_Z6_ S020_C2_Z6_ S020_C2_Z6_ C S020_C2_Z6_C S020_C2_Z8_ S020_C2_Z8_ S020_C2_Z8_ S020_C2_Z8_ C S020_C2_Z8_C Prepared for INPEX Cardno Page 49

58 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Location, Zone & Station Number Station Code Easting Northing Site C3 1 S020_C3_Z2_ S020_C3_Z2_ S020_C3_Z2_ S020_C3_Z2_ C S020_C3_Z2_C S020_C3_Z4_ S020_C3_Z4_ S020_C3_Z4_ S020_C3_Z4_ C S020_C3_Z4_C S020_C3_Z6_ S020_C3_Z6_ S020_C3_Z6_ S020_C3_Z6_ C S020_C3_Z6_C S020_C3_Z8_ S020_C3_Z8_ S020_C3_Z8_ S020_C3_Z8_ C S020_C3_Z8_C Site C4 1 S020_C4_Z2_ S020_C4_Z2_ S020_C4_Z2_ S020_C4_Z2_ C S020_C4_Z2_C S020_C4_Z4_ S020_C4_Z4_ S020_C4_Z4_ S020_C4_Z4_ C S020_C4_Z4_C S020_C4_Z6_ S020_C4_Z6_ S020_C4_Z6_ S020_C4_Z6_ C S020_C4_Z6_C IMPACT SITES Site I1 1 S020_I1_Z2_ S020_I1_Z2_ S020_I1_Z2_ S020_I1_Z2_ C S020_I1_Z2_C S020_I1_Z4_ S020_I1_Z4_ S020_I1_Z4_ S020_I1_Z4_ C S020_I1_Z4_C S020_I1_Z6_ Prepared for INPEX Cardno Page 50

59 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Location, Zone & Station Number Station Code Easting Northing Site I2 Site I3 2 S020_I1_Z6_ S020_I1_Z6_ S020_I1_Z6_ C S020_I1_Z6_C S020_I1_Z8_ S020_I1_Z8_ S020_I1_Z8_ S020_I1_Z8_ C S020_I1_Z8_C S020_I2_Z2_ S020_I2_Z2_ S020_I2_Z2_ S020_I2_Z2_ C S020_I2_Z2_C S020_I2_Z4_ S020_I2_Z4_ S020_I2_Z4_ S020_I2_Z4_ C S020_I2_Z4_C S020_I2_Z6_ S020_I2_Z6_ S020_I2_Z6_ S020_I2_Z6_ C S020_I2_Z6_C S020_I2_Z8_ S020_I2_Z8_ S020_I2_Z8_ S020_I2_Z8_ C S020_I2_Z8_C S020_I3_Z2_ S020_I3_Z2_ S020_I3_Z2_ S020_I3_Z2_ C S020_I3_Z2_C S020_I3_Z4_ S020_I3_Z4_ S020_I3_Z4_ S020_I3_Z4_ C S020_I3_Z4_C S020_I3_Z6_ S020_I3_Z6_ S020_I3_Z6_ S020_I3_Z6_ C S020_I3_Z6_C S020_I3_Z8_ S020_I3_Z8_ S020_I3_Z8_ S020_I3_Z8_ Prepared for INPEX Cardno Page 51

60 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Location, Zone & Station Number Station Code Easting Northing Site I4 Site I5 Site I6 C S020_I3_Z8_C S020_I4_Z2_ S020_I4_Z2_ S020_I4_Z2_ S020_I4_Z2_ C S020_I4_Z2_C S020_I4_Z4_ S020_I4_Z4_ S020_I4_Z4_ S020_I4_Z4_ C S020_I4_Z4_C S020_I4_Z6_ S020_I4_Z6_ S020_I4_Z6_ S020_I4_Z6_ C S020_I4_Z6_C S020_I4_Z8_ S020_I4_Z8_ S020_I4_Z8_ S020_I4_Z8_ C S020_I4_Z8_C S020_I5_Z2_ S020_I5_Z2_ S020_I5_Z2_ S020_I5_Z2_ C S020_I5_Z2_C S020_I5_Z4_ S020_I5_Z4_ S020_I5_Z4_ S020_I5_Z4_ C S020_I5_Z4_C S020_I5_Z6_ S020_I5_Z6_ S020_I5_Z6_ S020_I5_Z6_ C S020_I5_Z6_C S020_I5_Z8_ S020_I5_Z8_ S020_I5_Z8_ S020_I5_Z8_ C S020_I5_Z8_C S020_I6_Z2_ S020_I6_Z2_ S020_I6_Z2_ S020_I6_Z2_ C S020_I6_Z2_C S020_I6_Z4_ Prepared for INPEX Cardno Page 52

61 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Location, Zone & Station Number Station Code Easting Northing 2 S020_I6_Z4_ S020_I6_Z4_ S020_I6_Z4_ C S020_I6_Z4_C S020_I6_Z6_ S020_I6_Z6_ S020_I6_Z6_ S020_I6_Z6_ C S020_I6_Z6_C Prepared for INPEX Cardno Page 53

62 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Ichthys Nearshore Environmental Monitoring Program Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 L384-AW-REP APPENDIX B FLORA RESULTS Prepared for INPEX Cardno Page 46

63 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Appendix B-1 Flora Summary Tables B-1 A: Summary of Canopy Cover and Canopy Change Mean canopy cover change D2-B2 (± SE) at Control and Impact sites (data pooled for sites and assemblages). Net change calculated for Impact Control. Control Sites (%) Impact Sites (%) Impact Sites - Control Sites (%) Mean ±SE Mean ±SE Net change Mean canopy cover change (D2-B2) B-1 B: Summary of Seedling Growth Leaves Summary of mean percentage change (± SE) in leaf number (D2-B2, expressed as % of B2) at Control and Impact sites (data pooled for sites and assemblages). Net percentage change calculated for Impact Control. Control Sites (%) Impact Sites (%) Impact Sites - Control Sites (%) Mean ±SE Mean ±SE Net change Mean change in number of leaves (D2-B2) B-1 C: Summary of Seedling Growth Nodes Summary of mean percentage change (± SE) in node number (D2-B2, expressed as % of B2) at Control and Impact sites (data pooled for sites and assemblages). Net percentage change calculated for Impact Control. Control Sites (%) Impact Sites (%) Impact Sites - Control Sites (%) Mean ±SE Mean ±SE Net change Mean change in number of nodes (D2-B2) B-1 D: Summary of Seedling Survival Summary of mean seedling survival (number of seedlings in B2 number of seedlings in D2, expressed as % of B2) (± SE) at Control and Impact sites (data pooled for sites and assemblages). Net percentage change calculated for Impact Control. Control Sites (%) Impact Sites (%) Impact Sites -Control Sites (%) Mean ±SE Mean ±SE Net change Mean seedling survival (B2-D2) Prepared for INPEX Cardno Page 47

64 Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 Appendix B-1 Flora Summary Tables B-1 E: Seedling & Sapling Species Richness Summary of total mean seedling and sapling species richness (± SE) recorded during D2 for Control and Impact Treatments, for the four mangrove assemblages studied Site type Plant type Hinterland Margin Tidal Flat (Ceriops) Tidal Creek (Rhizophora) Seaward (Sonneratia) Seedling richness ±SE richness ±SE richness ±SE richness ±SE B2 D2 Net change (D2-B2) B2 D2 Net change (D2-B2) Control Impact Control Impact Control Impact Sapling richness ±SE richness ±SE richness ±SE richness ±SE Control Impact Control Impact Control Impact Prepared for INPEX Cardno Page 48

65 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures B-2 A: Canopy Cover in Baseline and Dredging Phases Mean percentage canopy cover (± SE) at Control and Impact sites during B1, B2 (Baseline) and D1 and D2 (Dredging) Phases. Prepared for INPEX Cardno Page 49

66 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures B-2 B: Canopy Cover for Sites and Assemblages Mean percentage canopy cover (± SE) recorded during B1, B2, D1 and D2 in at each site in the four assemblages (Control= C1-C4, Impact= I1-I6). Prepared for INPEX Cardno Page 50

67 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures B-2 C: Seedling Density in Four Assemblages Mean percentage seedling density per 1m2 (± SE) recorded during B1, B2, D1 and D2 in the four assemblages. Prepared for INPEX Cardno Page 51

68 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures. Continued B-2 C: Sapling Density in Four Assemblages Prepared for INPEX Cardno Page 52

69 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures. Continued B-2 D: Seedling Density for Sites and Assemblages Mean percentage seedling density per 1m2 (± SE) recorded during B1, B2, D1 and D2 in the four assemblages (Control= C1-C4, Impact= I1-I6). Prepared for INPEX Cardno Page 53

70 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures B-2 E: Leaf Change in All Species Combined for Sites and Assemblages Mean percentage leaf change (± SE) in all species combined recorded during D2 in the four assemblages (Control= C1-C4, Impact= I1-I6). Prepared for INPEX Cardno Page 54

71 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix B-2 Flora Summary Figures. Continued B-2 F: Nodal Change for All Species Combined in Three Assemblages Mean percentage node change (± SE) in all species combined recorded during D2 in three assemblages (Control= C1-C4, Impact= I1-I6). Prepared for INPEX Cardno Page 55

72 Quarterly Mangrove Community Health Report Dredging Report 2 Ichthys Nearshore Environmental Monitoring Program Quarterly Mangrove Community Health Monitoring Report Dredging Report 2 L384-AW-REP APPENDIX C FAUNA RESULTS Prepared for INPEX Cardno Page 56

73 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-1 Fauna Summary Tables C-1 A: Mean Invertebrate Species Richness Mean invertebrate species richness (± SE) at Control and Impact sites in four assemblages. Data represent means total species richness per sampling station, for B1/B2 (pooled) and D2. Invertebrate Species Richness Baseline D2 Treatment Site Assemblage Assemblage Type Mean spp. rich. (±) SE Mean spp. rich. Control C1 2 Tidal Creek Tidal Flat Hinterland Margin Seaward C2 2 Tidal Creek Tidal Flat (±) SE 6 Hinterland Margin Seaward C3 2 Tidal Creek Tidal Flat Hinterland Margin Seaward C4 2 Tidal Creek Tidal Flat Hinterland Margin Impact I1 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I2 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I3 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I4 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I5 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I6 2 Tidal Creek Tidal Flat Hinterland Margin Prepared for INPEX Cardno Page 57

74 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-1 Fauna Summary Tables C-1 B: Mean Invertebrate Abundance Mean invertebrate abundance (± SE) at Control and Impact sites within four mangrove assemblages. Data represent means for total abundance per sampling station, for B1/B2 (pooled) and D2. Invertebrate Species Abundance Baseline D2 Treatment Site Assemblage Assemblage Type Mean spp. rich. (±) SE Mean spp. rich. (±) SE Control C1 2 Tidal Creek Tidal Flat Hinterland Margin Seaward C2 2 Tidal Creek Tidal Flat Hinterland Margin Seaward C3 2 Tidal Creek Tidal Flat Hinterland Margin Seaward C4 2 Tidal Creek Tidal Flat Hinterland Margin Impact I1 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I2 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I3 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I4 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I5 2 Tidal Creek Tidal Flat Hinterland Margin Seaward I6 2 Tidal Creek Tidal Flat Hinterland Margin Prepared for INPEX Cardno Page 58

75 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-2 Fauna Species Lists C-2 A: List of New Fauna Species Records List of 48 new fauna species records comprising 10 ants, 11 worms, 11 molluscs (including 9 gastropods and 2 bivalves), 12 crustaceans, 3 fish and 1 sponge recorded during B1/B2 to D2 for the Mangrove Community Health Monitoring Program. New NT and Australian records denoted in bold type. New Fauna List Species name Family Taxonomic group Notes Survey Aoridae sp. 2 Aoridae amphipod New DH mangrove record D1 Aoridae sp. 4 Aoridae amphipod New DH mangrove record B1, B2 Gammarid sp. 2 Gammaridea amphipod New DH mangrove record D2 Arnoldius sp.1 Formicidae ant New NT record B1, B2 Camponotus sp.43 Formicidae ant New DH mangrove record B1, B2 Camponotus sp.44 Formicidae ant New NT record B1, B2 Camponotus sp.9 Formicidae ant New DH mangrove record B1, B2 Iridomyrmex angusticeps (bicknelli group) Formicidae ant New DH mangrove record D1 Monomorium sp. nr. turneri Formicidae ant New DH mangrove record B1, B2 Pheidole megacephala** Formicidae ant New DH mangrove record B1, B2 Pheidole sp. 3 (variabilis group) Formicidae ant New DH mangrove record D1 Polyrachis sp.28 Formicidae ant New NT record B1, B2 Tapinoma sp. D Formicidae ant New DH mangrove record D1 Nuculana sp. Nuculanidae bivalve New DH mangrove record B1, B2 Leionucula superba Nuculidae bivalve New DH mangrove record D1 Pinnotheres sp.1 Pinnotheridae crab New DH mangrove record D1 Zehntheria sp. Pilumnidae crab New DH mangrove record D2 Omobranchus ferox Blenniidae fish New DH mangrove record D1 Odontoleotris macrodon Eleotridae fish New DH mangrove record B1, B2 Callogobius sp. Gobiidae fish New DH mangrove record B1, B2 Murchisonella sp. Anisocyclidae gastropod New DH record D1 Dendrodoris cf. nigra Dendrodorididae gastropod New DH mangrove record D1 Prepared for INPEX Cardno Page 59

76 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 A: New Fauna Species Records. Continued New Fauna List Species name Family Taxonomic group Notes Survey Cassidula sp.4 Ellobidae gastropod New DH record B1, B2 Auriculastra sp.2 Ellobiidae gastropod New DH record D1 Epitonium sp. Epitoniidae gastropod New DH mangrove record D1 Phenacolepas sp.1 Phenacolepididae gastropod New DH record B1, B2 Odostomia sp. 3 Pyramidellidae gastropod New DH record B1, B2 Odostomia sp. 4 Pyramidellidae gastropod New DH mangrove record D2 Turbonilla sp. 2 Pyramidellidae gastropod New DH mangrove record D2 Anthuridea sp. Anthuridea * isopod New DH mangrove record B1, B2 Cymothoidae sp. 6 Cymothoidae Isopod New DH mangrove record D2 Gnathia sp.1 Gnathiidae isopod New DH mangrove record B1, B2 Gnathia sp.2 Gnathiidae Isopod New DH mangrove record D1 Podocopa sp. Podocopa* shrimp New DH mangrove record D2 Sponge sp. 3 Demospongiae** sponge New DH mangrove record D2 Apseudes sp.2 Tanaidaceae tanaid New DH mangrove record D1 Apseudes sp.3 Tanaidaceae tanaid New DH mangrove record B1, B2 Capitella sp. 2 Capitellidae worm New DH record D1 Ophiodromus sp. Hesionidae worm New DH mangrove record D1 Euclymene sp. 1 Maldanidae worm New DH mangrove record D1 Maldanid sp. 5 Maldanidae worm New DH mangrove record D1 Dendronereis sp. Nereididae worm New Australian record D1 Ophelina sp. 1 Opheliidae worm New DH mangrove record D1 Uncorbinia breribranctuata Orbiniidae worm New DH mangrove record D1 Ancistrosyllis sp. Pilargiidae worm New DH mangrove record B1, B2 Lepidonotus sp. 2 Polynoidae worm New DH record D1 Prepared for INPEX Cardno Page 60

77 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 A: List of New Fauna Species Records cont. New Fauna List Species name Family Taxonomic group Notes Survey Odontosyllis sp. 1 Syllidae worm New DH record D1 Syllis cf. gracilis Syllidae worm New DH mangrove record D1 ** Introduced species NB: Pheidole sp. 38 (group L) is now Pheidole sp. 22 (A. Andersen pers comm.) Prepared for INPEX Cardno Page 61

78 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-2 Fauna Species Lists. Continued C-2 B: Molluscs Species List List of 89 mollusc species (including 61 gastropods, 26 bivalves, 1 cephalopod and 1 chiton) recorded during B1, B2, D1 and D2 surveys. Presence at Control and Impact sites is denoted by an X. Species recorded for the first time during D2 are denoted by bold type (n = 1). Molluscs Species List Species name Family Taxonomic group Control Impact Enigmonia aenigmatica Anomiidae Bivalve X X Enigmonia aenigmatica Anomiidae Bivalve X X Arcopsis afra Arcidae Bivalve X X Polymesoda erosa Corbiculidae Bivalve X X Glauconome cerea Glauconomidae Bivalve X Glauconome plankta Glauconomidae Bivalve X Glauconome virens Glauconomidae Bivalve X Isognomon ephippium Isognominidae Bivalve X X Laturnula faba Laternulidae Bivalve X X Austriella corrugata Lucinidae Bivalve X Indoaustriella sp. 1 Lucinidae Bivalve X Sphenia perversa Lyonsiidae Bivalve X X Arcuatula sp. Mytilidae Bivalve X Brachidontes maritimus Mytilidae Bivalve X X Limnoperna sp. Mytilidae Bivalve X X Modiolus sp. Mytilidae Bivalve X Leionucula superba Nuculidae Bivalve X Booneostrea cuculina Ostreidae Bivalve X X Planostrea pestigris Ostreidae Bivalve X Saccostrea cucullata Ostreidae Bivalve X X Siliqua sp. Pharidae Bivalve X X Martesia striata Pholadidae Bivalve X X Macoma sp. Tellinidae Bivalve X X Bactronophorus thoracites Teredinidae Bivalve X Bankia australis Teredinidae Bivalve X Dicyathifer manii Teredinidae Bivalve X X Cycladicama subquadrata Ungulinidae Bivalve X Pitar inconstans Veneridae Bivalve X Craspedoplax sp.nov. Acanthochitonidae Chiton X Salinator fragilis Amphibolidae Gastropod X X Murchisonella sp. Anisocyclidae Gastropod X Assiminea sp.1 Assimineidae Gastropod X X Assiminea sp.2 Assimineidae Gastropod X X Assiminea sp.3 Assimineidae Gastropod X X Pseudanchis duclosianus Columbellidae Gastropod X Zafra minuscula Columbellidae Gastropod X X Dendrodoris cf.nigra Dendrodorididae Gastropod X Auriculastra nevillei Ellobiidae Gastropod X X Auriculastra siamensis Ellobiidae Gastropod X X Auriculastra sp.2 Ellobiidae Gastropod X X Prepared for INPEX Cardno Page 62

79 Quarterly Mangrove Community Health Report Dredging Report 2 Molluscs Species List Species name Family Taxonomic group Control Impact Auriculastra subula Ellobiidae Gastropod X X Cassidula aff. doliolum Ellobiidae Gastropod X X Cassidula angulifera Ellobiidae Gastropod X X Cassidula cf. granulosa Ellobiidae Gastropod X X Cassidula coelata Ellobiidae Gastropod X X Cassidula decussata Ellobiidae Gastropod X X Cassidula sp.3 Ellobiidae Gastropod X X Cassidula sp.4 Ellobiidae Gastropod X Ellobium aurisjudae Ellobiidae Gastropod X Laemodonta punctatostriata Ellobiidae Gastropod X X Melampus sp.1 Ellobiidae Gastropod X X Melampus sp.2 Ellobiidae Gastropod X X Ophicardelus sp. Ellobiidae Gastropod X Epitonium sp. Epitoniidae Gastropod X Atys sp. Haminoeidae Gastropod X Haminoea sp. Haminoeidae Gastropod X X Iravadia australis Iravadiidae Gastropod X X Iravadia quadrasi Iravadiidae Gastropod X Iravadia sp. 1 Iravadiidae Gastropod X Pseudomerelina mahimensis Iravadiidae Gastropod X Littoraria articulata Littorinidae Gastropod X X Littoraria filosa Littorinidae Gastropod X X Peasiella tantilla Littorinidae Gastropod X Patelloida cryptalirata Lottidae Gastropod X Pugilina conchlidium Melongenidae Gastropod X Chicoreus capucinus Muricidae Gastropod X X Thais trigonus Muricidae Gastropod X X Nassarius melanoides Nassariidae Gastropod X X Nassarius moestus Nassariidae Gastropod X X Nerita balteata Neritidae Gastropod X X Neritina violacea Neritidae Gastropod X X Óctopus sp. Octopodidae Cephalopod X Onchidium sp.1 Onchidiidae Gastropod X X Onchidium sp.2 Onchidiidae Gastropod X Onchidium sp.3 Onchidiidae Gastropod X X Onchidium sp.6 Onchidiidae Gastropod X X Onchidium sp.7 Onchidiidae Gastropod X Phenacolepas sp.1 Phenacolepididae Gastropod X Cerithidea anticipata Potamididae Gastropod X X Cerithideopsilla cingulata Potamididae Gastropod X Cerithideopsis largillierti Potamididae Gastropod X X Telescopium telescopium Potamididae Gastropod X X Terebralia palustris Potamididae Gastropod X Terebralia semistriata Potamididae Gastropod X X Terebralia sulcata Potamididae Gastropod X X Prepared for INPEX Cardno Page 63

80 Quarterly Mangrove Community Health Report Dredging Report 2 Molluscs Species List Species name Family Taxonomic group Control Impact Odostomia sp.1 Pyramidellidae Gastropod X Odostomia sp.2 Pyramidellidae Gastropod X Odostomia sp.3 Pyramidellidae Gastropod X Odostomia sp.4 Pyramidellidae Gastropod X Turbonilla sp. Pyramidellidae Gastropod X Turbonilla sp.2 Pyramidellidae Gastropod X Retusa sp. Retusidae Gastropod X Stenothyra sp. Stenothyridae Gastropod X 92 Species C-2 C: Decapod Crabs List of 54 decapod crab species recorded during B1, B2, D1 and D2 surveys conducted between June 2012 and February Presence at Control and Impact sites is denoted by an X. Species recorded for the first time during D2 are denoted by bold type (n = 1). Decapod Crab Species List Species name Family Control Impact Baruna trigranulum Camptandriidae X X Camptandrium cf. Mcneilli Camptandriidae X X Camptandrium sp.1 Camptandriidae X X Camptandrium sp.2 Camptandriidae X X Cleistostoma sp.nov. Camptandriidae X X Paracleistostma wardi Camptandriidae X X Paracleistostoma sp. nov Camptandriidae X X Clibanarius longitarsus Diogenidae X X Diogenes sp. Diogenidae X X Myomenippe fornassinii Eriphiidae X X Clistocoeloma merguiensis Grapsidae X X Episesarma sp.nov. Grapsidae X X Hemigrapsus sp. 1 Grapsidae X X Ilyograpsus paludicola Grapsidae X X Metopograpsis frontalis Grapsidae X X Metopograpsis latifrons Grapsidae X X Nanosesarma batavicum Grapsidae X X Neosarmatium meinerti Grapsidae X X Neosesarma sp. Grapsidae X X Parasesarma moluccensis Grapsidae X X Perisesarma darwinensis Grapsidae X X Perisesarma semperi (longicristatum) Grapsidae X X Sarmatium germaini Grapsidae X X Sarmatium hegerli Grapsidae X X Sarmatium unidentalis Grapsidae X X Selatium brockii Grapsidae X X Sesarmoides borneensis Grapsidae X X Prepared for INPEX Cardno Page 64

81 Quarterly Mangrove Community Health Report Dredging Report 2 Decapod Crab Species List Species name Family Control Impact Amarinus sp. Hymenosomatidae X X Elamenopsis lineata Hymenosomatidae X Neorhynchoplax sp.nov. Hymenosomatidae X X Neorhynchoplax sp.2 Hymenosomatidae X Neorhynchoplax torrensica Hymenosomatidae X Ilyoplax strigicarpus Ocypodidae X X Macropthalmus darwinensis Ocypodidae X X Macropthalmus latreillei Ocypodidae X Macropthalmus sp.nov. Ocypodidae X X Uca capricornis Ocypodidae X X Uca flammula Ocypodidae X X Uca hirsutimanus Ocypodidae X X Uca mjoebergi Ocypodidae X Uca polita Ocypodidae X X Uca seismella Ocypodidae X Uca signata Ocypodidae X X Pagurus sp. Paguridae X Heteranope glabra Pilumnidae X X Heteranope longipedes Pilumnidae X X Pinnotheres sp.1 Pinnotheridae X Petrolisthes haplodactylus Porcellanidae X Petrolisthes kranjiensis Porcellanidae X X Petrolisthes limicola Porcellanidae X X Scylla serrata Portunidae X Thalamita sp.1 Portunidae X X Cryptolutea cf. sagamiensis Xanthidae X Epixanthus dentatus Xanthidae X 54 Species C-2 E: Other Crustaceans Species List List of 46 Crustacean species (other than decapod crabs) recorded during B1, B2, D1 and D2 surveys conducted between June 2012 and February Presence at Control and Impact sites is denoted by an X. Species recorded for the first time during D2 are denoted by bold type (n = 3). Other Crustaceans Species name Family Taxonomic group Control Impact Aoridae sp.1 Aoridae amphipod X X Aoridae sp.2 Aoridae amphipod X X Aoridae sp.3 Aoridae amphipod X Aoridae sp.4 Aoridae amphipod X X Chelorchestia sp.1 Talitridae amphipod X X Gammarid sp. 2 Gammaridea ++ amphipod X Protohyale sp. Hyalidae amphipod X X Melitidae sp. Melitidae amphipod X X Orchestia sp.1 Talitridae amphipod X X Prepared for INPEX Cardno Page 65

82 Quarterly Mangrove Community Health Report Dredging Report 2 Other Crustaceans Species name Family Taxonomic group Control Impact Orchestia sp.2 Talitridae amphipod X Taylorchestia sp.1 Talitridae amphipod X X Striatobalanus amaryllis Balanidae barnacle X Microeuraphia withersi Chthamalidae barnacle X X Anthuridea sp. Anthuridea ++ isopod X Chitinopsis sp. Cymothoidae isopod X Cymothoidae sp.1 Cymothoidae isopod X X Cymothoidae sp.2 Cymothoidae isopod X Cymothoidae sp.3 Cymothoidae isopod X X Cymothoidae sp.4 Cymothoidae isopod X Cymothoidae sp.5 Cymothoidae isopod X Cymothoidae sp.6 Cymothoidae isopod X X Gnathia sp.1 Gnathiidae isopod X Gnathia sp.2 Gnathiidae isopod X Ligia australis Ligiidae isopod X X Limicolana dinjirra Limnoriadae isopod X X Oniscidae sp.1 Oniscidae isopod X Oniscidae sp.2 Oniscidae isopod X Oniscidae sp.3 Oniscidae isopod X Sphaeromatidae sp.1 Sphaeromatidae isopod X X Sphaeromatidae sp.2 Sphaeromatidae isopod X Sphaeromatidae sp.3 Sphaeromatidae isopod X Thalassina squamifera Thalassinidae mud lobster X Alpheus sp. Alpheidae shrimp X X Athanus sp.1 Alpheidae shrimp X Athanus sp.2 Alpheidae shrimp X Salmoneus seticheles Alpheidae shrimp X X Leandrites celebensis Palaemonidae shrimp X X Palaemon serrifer Palaemonidae shrimp X Periclimenes suvadivensis Palaemonidae shrimp X X Potamalpheops hanleyi Palaemonidae shrimp X X Metapenaeus insolitus Penaeidae shrimp X X Podocopa sp. Podocopa + shrimp X Apseudes sp.1 Tanaidaceae tanaid X X Apseudes sp.2 Tanaidaceae tanaid X X Apseudes sp.3 Tanaidaceae tanaid X Wolffogebia inermis Upogebiidae upogebiid X X 46 Species Prepared for INPEX Cardno Page 66

83 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 D: Worm Species List List of 80 annelid and other worm species recorded during B1, B2, D1 and D2 surveys conducted between June 2012 and February Presence at Control and Impact sites is denoted by an X. No new species records were documented during the D2 survey. Worm Species List Species name Family Control Impact Amphicteis sp.1 Ampharetidae X Isolda pulchella Ampharetidae X X Capitella sp.1 Capitellidae X Capitella sp.2 Capitellidae X Heteromastus sp.1 Capitellidae X X Mastobranchus sp.1 Capitellidae X X Mediomastus sp.1 Capitellidae X X Notomastus sp. Capitellidae X Cirriformia sp.1 Cirratulidae X X Monticellina sp.1 Cirratulidae X Marphysa mossambica Eunicidae X Nematonereis sp. Eunicidae X X Glycera nicobarica Glyceridae X X Glycera sp. Glyceridae X Glycera sp. 2 Glyceridae X Ophiodromus sp. Hesionidae X Scoletoma sp.1 Lumbrineridae X X Scoletoma sp.2 Lumbrineridae X Magelona sp. 1 Magelonidae X Euclymene sp.1 Maldanidae X Maldanid sp.5 Maldanidae X Gordian worm sp. Nectonematoida X X Cerebratulus sp. Nemertea X X Nemertea sp.2 Nemertea X Nephtys mesobranchia Nephtyidae X X Ceratonereis australis Nereididae X Ceratonereis NTMW6742 Nereididae X X Dendronereis sp. Nereididae X Leonnates crinitus Nereididae X X Leonnates persicus Nereididae X Leonnates stephensoni Nereididae X Namalycastis sp.1 Nereididae X Namalycastis abiuma Nereididae X X Namalycastis cf. fauveli Nereididae X Namalycastis nicolea Nereididae X Namanereis cf. malaitae Nereididae X Namereis amboinensis Nereididae X Namotonereis unicornis Nereididae X Neanthes cf. biseriata Nereididae X X Neanthes sp.3 Nereididae X Nereis sp.1 Nereididae X X Prepared for INPEX Cardno Page 67

84 Quarterly Mangrove Community Health Report Dredging Report 2 Worm Species List Species name Family Control Impact Paraleonnates bolus Nereididae X X Perinereis aibuhitensis Nereididae X X Perinereis nigropunctata Nereididae X X Perinereis singaporiensis Nereididae X X Rullierinereis sp. Weddell Nereididae X Arabelloneris broomensis Oenonidae X X Drilonereis sp. Oenonidae X Armandia sp.1 Opheliidae X Ophelina sp.1 Opheliidae X Leitoscoloplos latibranchus Orbiniidae X X Uncorbinia breribranctuata Orbiniidae X Uncorbinia sp. Orbiniidae X Phyllodoce sp.1 Phyllodocidae X X Phyllodoce sp.2 Phyllodocidae X Sige sp. Phyllodocidae X Ancistrosyllis sp. Pilargiidae X Lepidonotus sp.1 Polynoidae X X Lepidonotus sp.2 Polynoidae X Lepidonotus kumari Polynoidae X Olgalepidonotus kumari Polynoidae X X Branchiomma sp. 1 Sabellidae X Megalomma sp. 1 Sabellidae X Pomatoleios kraussii Serpulidae X X Phascolosom arcuatum Sipunculidae X X Phascolosoma cf. arcuatum Sipunculidae X Sipunculid sp. 2 Sipunculidae X Sipunculid sp. 3 Sipunculidae X Dipolydora sp. 1 Spionidae X Prionospio cirrifera complex Spionidae X Prionospio sp.1 Spionidae X X Prionospio sp.2 Spionidae X Odontosyllis sp.1 Syllidae X Syllis cf. gracilis Syllidae X Syllis sp. 1 Syllidae X Lanicola lobata Terebellidae X Terebella tantabiddycreekensis Terebellidae X Listriolobus bulbocaudatus Thalassematidae X X Terebellides kowinka Trichobranchidae X Trochochaeta sp. Trichobranchidae X 80 Species Prepared for INPEX Cardno Page 68

85 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 F: Ants Species List List of 39 ant species recorded during B1, B2, D1 and D2 surveys conducted between June 2012 and February Presence at Control and Impact sites is denoted by an X. No new ant species were recorded during D2. Ants Species List Species name Family Control Impact Arnoldius sp. 1 Formicidae X Bothroponera sp.1 Formicidae X X Camponotus anderseni Formicidae X Camponotus sp.1 (reticulatus group) Formicidae X Camponotus sp.10 (novaehollandiae group) Formicidae X Camponotus sp.3 (janeti group) Formicidae X X Camponotus sp.9 Formicidae X Camponotus sp.43 Formicidae X Camponotus sp.44 Formicidae X X Crematogaster sp.2 (australis group) Formicidae X X Crematogaster sp.3 (group A) Formicidae X X Crematogaster sp.6 Formicidae X X Crematogaster sp.8 Formicidae X X Crematogaster sp.9 Formicidae X X Hypoponera sp. 1 Formicidae X Monomorium nr. turneri Formicidae X Nylanderia sp.4 (vaga group) Formicidae X X Oecophylla smaragdina Formicidae X X Opisthopsis major Formicidae X X Paratrechina longicornis Formicidae X X Pheidole megacephala** Formicidae X Pheidole sp.3 (variabilis group.) Formicidae X Pheidole sp.22 Formicidae X Podomyrma nr. basalis Formicidae X Polyrachis alligator Formicidae X X Polyrachis sp.17 Formicidae X X Polyrachis sp.28 Formicidae X Polyrhachis constricta Formicidae X X Polyrhachis senilis Formicidae X Polyrhachis sokolova Formicidae X X Polyrhachis terpsichore Formicidae X X Solenopsis sp.1 Formicidae X X Tapinoma sp.3 Formicidae X X Tapinoma sp.6 (minutum group) Formicidae X X Tapinoma sp. D Formicidae X Tetraponera allobrans Formicidae X Tetraponera nitida Formicidae X Tetraponera punctulata Formicidae X X Trachymesopus darwinii Formicidae X 39 species Prepared for INPEX Cardno Page 69

86 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 G: Fish Species List List of 24 fish species recorded during B1, B2, D1 and D2 surveys. Presence at Control and Impact sites is denoted by an X. No new fish species were recorded during D2 Fish Species List Species name Family Control Impact Omobranchus ferox Blenniidae X Omobranchus verticalis Blenniidae X Bostrychus sinensis Eleotridae X Incara multisquamata Eleotridae X Odontoleotris macrodon Eleotridae X X Acentrogobius viridipunctatus Gobiidae X X Amoya gracilis Gobiidae X X Amoya sp. 2 Gobiidae X X Boleopthalmus birdsongi Gobiidae X Callogobius sp. Gobiidae X Eugnathogobius polylepis Gobiidae X X Hemigobius hoevenii Gobiidae X?Hippychthys parvicarinatus Syngnathidae X Gobiopterus sp. Gobiidae X Mugilogobius filifer Gobiidae X X Mugilogobius rivulus Gobiidae X Pandaka lidwilli Gobiidae X X Parioglossus palustris Gobiidae X X Periopthalmus argentilineatus Gobiidae X Periopthalmus darwinii sp. nov Gobiidae X X Periopthalmus minutus Gobiidae X X Periopthalmus novaeguineaensis Gobiidae X Pseudogobius poicilosoma Gobiidae X X Pseudogobius sp. 3 Gobiidae X X 24 Species Prepared for INPEX Cardno Page 70

87 Quarterly Mangrove Community Health Report Dredging Report 2 C-2 H: Other Invertebrate Species List List of 10 other invertebrate species recorded during B1, B2, D1 and D2 at Control and Impact sites. Species recorded for the first time during D2 are denoted by bold type (n = 1). Other Invertebrates Species List Species name Family Taxonomic group Control Impact Anemone sp. 1 Actiniaria Anemone X Anemone sp. 3 Actiniaria Anemone X Anemone sp. 4 Actiniaria Anemone X Ophiactis cf. luteomaculata Ophiactidae Brittle star X X Amphibiobeania epiphylla Beaniidae Bryozoan X X Bryozoan sp.2 Bryozoa* Bryozoan X Holothuroidea sp. Holothuroidea Echinoderm X X Sponge sp. 1 Demospongiae ++ Sponge Sponge sp. 2 Demospongiae ++ Sponge X Sponge sp. 3 Demospongiae + Sponge X 10 Species *Phylum; ++ Suborder Prepared for INPEX Cardno Page 71

88 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-3 C-3 A: Ant Species Richness Fauna Summary Figures Figure C-3 A: Mean ant species richness (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. Prepared for INPEX Cardno Page 72

89 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-3 Fauna Summary Figures C-3 B: Crab Species Richness Figure C-3 B: Mean crab species richness (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. C-3 C: Crab Abundance Figure C-3 C: Mean crab abundance (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. Prepared for INPEX Cardno Page 73

90 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-3 Fauna Summary Figures C-3 D: Other Crustacean Species Richness Figure C-3 D: Mean other crustacean species richness (± SE) in the four main assemblages from landward (L) to seaward (R) recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. C-3 E: Other Crustacean Species Abundance Figure C-3 E: Mean other crustacean species abundance (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. Prepared for INPEX Cardno Page 74

91 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-3 Fauna Summary Figures C-3 F: Mollusc Species Richness Figure C-3 F: Mean mollusc species richness (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. C-3 G: Mollusc Species Abundance Figure C-3 G: Mean mollusc abundance (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. Prepared for INPEX Cardno Page 75

92 Quarterly Mangrove Community Health Report Dredging Report 2 Appendix C-3 Fauna Summary Figures C-3 H: Worm Species Richness Figure C-3 H: Mean worm species richness (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. C-3 I: Worm Species Abundance Figure C-3 I: Mean worm abundance (± SE) in the four main assemblages from landward to seaward recorded during B1, B2, D1 and D2 surveys at Control and Impact sites. Prepared for INPEX Cardno Page 76