Bimonthly Water Quality and Subtidal Sedimentation Report 47

Transcription

1 Bimonthly Water Quality and Subtidal Sedimentation Report 47 Ichthys Nearshore Environmental Monitoring Program L384-AW-REP-10193L384-AW-REP L384-AW-REP Prepared for INPEX January 2014

2 Document Information Prepared for Project Name File Reference Job Reference INPEX L384-AW-REP-10196_0_Bimonthly Water Quality and Subtidal Sedimentation Report 7.docm L384-AW-REP Date January 2014 Contact Information (NSW/ACT) Pty Ltd (WA) Pty Ltd (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 Initials Reviewer Initials A 09/12/2013 Andrew Bradford AB David van Senden DvS Michael Hughes MH Joanna Lamb JL B 23/12/2013 Andrew Bradford AB Christopher Holloway CGH Michael Hughes MH C 07/01/2014 Andrew Bradford AB Keith Wallace KW Michael Hughes MH Joanna Lamb JL 0 09/01/2014 Michael Hughes MH Joanna Lamb JL This document is produced by solely for the benefit and use by the client in accordance with the terms of the engagement for the performance of the Services. 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. ii

3 Executive Summary The East Arm (EA) Dredging and Spoil Disposal Management Plans (DSDMP) (INPEX 2012) and Gas Export Pipeline (GEP) DSDMP (INPEX 2013) includes the monitoring of potential impact on water quality from dredging and spoil disposal activities associated with the Ichthys Gas Field Development Project (the Project) in and around Darwin Harbour. This report provides an assessment of water quality data and an examination of potential dredging-related effects on water quality between 1 September 2013 and 31 October 2013, covering a period of 61 days. The report collates information from the Water Quality and Subtidal Sedimentation Monitoring Program (WQSSMP), data provided by the Australian Bureau of Meteorology (BOM), the USA Atmospheric Radiation Measurement Climate Research Facility (ARM), and the USA National Aeronautics and Space Administration (NASA). There were no Level 1 dry season trigger exceedances recorded over the reporting period. Season One EA dredging within Darwin Harbour operated over the wet season from 27 August 2012 to 30 April 2013 with overall progress approximately 43% complete. Season Two dredging commenced on 23 October 2013 with Trailer Suction Hopper Dredging (TSHD) along sections of the GEP. Therefore, the sampling period covered in this report includes only a brief period of dredging at the commencement of Season Two dredging. The relatively low total rainfall over this bimonthly sampling period (99 mm) and the generally low daily-averaged significant wave height (Hs <0.5 m) suggests the results reported here are indicative of dry season conditions. The dominant driver of turbidity variations was the tide. Consequently, the benthic light conditions were controlled mostly by tidal variations in turbidity and water level. It should be noted that the trend of reduced atmospheric pressure, increasing rainfall, increasing air and water temperature, and a switch in wind direction from the easterly to westerly sectors over the reporting period indicate a transitioning from dry to wet season conditions. The meteorological and oceanographic conditions reported here are broadly consistent with conditions reported for the corresponding period last year. The maximum tide range in the current reporting period, however, was 1.1 m smaller than last year. During the current reporting period turbidity levels were low across all sites and, overall, were representative of dry season conditions. Peak values of daily-averaged near-bed turbidity were generally well below 20 NTU and median daily-averaged values were below 6 NTU. This pattern is broadly consistent with observations from the corresponding period last year, although turbidity at Charles Point and Mandorah were smaller in the current reporting period Empirical model turbidity residuals were generally low (less than ±6 NTU), indicating a reasonable correlation between predicted and measured turbidity. The model continues to perform well across sites and through time as an interpretative and predictive tool. Turbidity levels were well below those recorded during the wet season when sea, swell and rainfall all contributed to the turbidity signal. Total daily Photosynthetically Active Radiation (PAR) levels were consistent with the previous two months and generally higher than the wet season periods at all sites. Darwin Harbour Inner sites reported median values of 1.0 to 3.0 mol/m 2 /day. Median values at Darwin Outer sites ranged from 2 to 7 mol/m 2 /day. The levels of light recorded during the current reporting period were consistent with the corresponding period last year and with the clear waters and high light penetration conditions characteristic of the dry season. Surface turbidity measurements and water profiles provide information on the vertical structure of the water column and general mixing dynamics. Both surface turbidity measurements and water profiles indicate a typical dry season structure with vertically well-mixed conditions and weak horizontal gradients associated with tidal mixing of higher turbidity waters in shallow high current resuspension areas and lower turbidity waters. Water temperature at all sites displayed an increasing trend from 27ºC at the beginning of September 2013 to 31ºC at the end of the reporting period, 30 October This trend was also observed in 2012 ( 2013a) and is typical of the Darwin Harbour waters during the spring transition from the cooler winter months to the warmer summer months. iii

4 Glossary Term or Acronym ARM B1 BHD BOM Chl-a CoC CSD CTD Definition Atmospheric Radiation Measurement Climate Research Facility WQSSMP Baseline Report Backhoe Dredger Bureau of Meteorology Chlorophyll-a Chain of Custody Cutter Suction Dredger Conductivity, Temperature and Depth D1 WQSSMP Bimonthly Report 1 27 August 2012 to 4 November 2012 D2 WQSSMP Bimonthly Report 2 1 November 2012 to 31 December 2012 D3 WQSSMP Bimonthly Report 3 1 January 2013 to 28 February 2013 D4 WQSSMP Bimonthly Report 4 1 March 2013 to 9 May 2013 D5 WQSSMP Bimonthly Report 5 1 May 2013 to 30 June 2013 D6 WQSSMP Bimonthly Report 6 1 July 2013 to 31 August 2013 D7 WQSSMP Bimonthly Report 7 1 September 2013 to 31 October 2013 DO DSDMP EA GEP IMOS ISMO LAT MAA MAFRL MODIS Dissolved Oxygen Dredging and Spoil Disposal Management Plan East Arm Gas Export Pipeline Integrated Marine Observing System In-Situ Marine Optics Lowest Astronomical Tide Microanalysis Australia (Laboratory) Marine and Freshwater Research Laboratory Moderate Resolution Imaging Spectroradiometer iv

5 Term or Acronym MOF NASA NEMP NRS NTC NTU PAR PPMP PSD PSU PVC QA/QC SD SP1 SP2 SP3 SP4 SP5 TARP TD TDIM TSHD TSS WQSSMP ZoI ZoMI Definition Module Offloading Facility National Aeronautics and Space Administration Nearshore Environmental Monitoring Plan IMOS National Reference Station BOM National Tidal Centre Nephelometric Turbidity Units Photosynthetically Active Radiation Primary Productivity Monitoring Program Particle Size Distribution Practical Salinity Units Polyvinyl Chloride Quality Assurance and Quality Control Standard Deviation Dredging Footprint Separable Portion 1 - MOF Dredging Footprint Separable Portion 2 - Jetty Pocket Dredging Footprint Separable Portion 3 - Berth Area Dredging Footprint Separable Portion 4 - Approach Channel, Berth Approach and Turning Area Dredging Footprint Separable Portion 5 - Walker Shoal Trigger Action Response Plan Temperature and Depth Total Dry Inorganic Mass Trailing Suction Hopper Dredger Total Suspended Solids Water Quality and Subtidal Sedimentation Monitoring Program Zone of Influence Zone of Moderate Impact v

6 Table of Contents Executive Summary Glossary iii iv 1 Introduction Background Requirement to Monitor Water Quality Reactive and Informative Monitoring Programs Purpose of this Report 3 2 Methodology External Sources of Information BOM IMOS ARM NASA Monitoring Sites In-Situ Measurements Water Profiles Water Samples Sediment Samples Additional Analysis Turbidity Empirical Model Light Extinction Coefficient TARP Data Management and Quality Control 18 3 Dredging Operations 19 4 Results External Sources of Information BOM ARM NASA In-Situ Measurements Turbidity Photosynthetically Available Radiation Salinity and Water Temperature Chlorophyll-a Water Profiles Water Samples WQSSMP Sediment Trap Samples 34 5 Discussion MetOcean Conditions Turbidity Turbidity Empirical Model Benthic Light 37 6 References 38 vi

7 Tables Table 1-1 Summary of the WQSSMP 2 Table 2-1 BOM data summary 4 Table 2-2 ARM data summary 5 Table 2-3 NASA data summary 5 Table 2-4 Summary of reactive water quality monitoring sites 6 Table 2-5 Summary of water quality monitoring sites 7 Table 2-6 Deployment summary 8 Table 2-7 Monitoring station sensor specifications 13 Table 2-8 Water Profiler sensor specifications 13 Table 2-9 WQSSMP water profiling summary 14 Table 2-10 WQSSMP water sampling summary 15 Table 2-11 Sediment trap summary 16 Table 2-12 Level 1 trigger summary 18 Table 3-1 Dredge footprint summary 19 Table 4-1 Logged near-bed turbidity data return 25 Table 4-2 Logged near-surface turbidity data return 26 Table 4-3 Near-bed turbidity statistics 27 Table 4-4 Near-surface turbidity statistics 27 Table 4-5 Correlation between near-bed and near-surface turbidity measurement 29 Table 4-6 Near-bed total PAR data return 30 Table 4-7 PAR statistics at -3 m LAT 31 Table 4-8 F31 (September 2013) - sedimentation trap results by total dry inorganic weight analysis 34 Table 4-9 F32 (October 2013) - sediment trap results by total dry inorganic weight analysis 35 Figures Figure 2-1 Figure 2-2 Figure 2-3 Figure 3-1 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 In-situ water quality monitoring sites 9 Field operations summary 10 Monitoring site configuration 11 Dredging footprint 20 BOM Darwin Airport wind rose 21 BOM Darwin Airport wind speed and wind direction 22 BOM Darwin Airport rainfall; and ARM Darwin Airport PAR 22 BOM Darwin Airport air temperature, relative humidity and barometric pressure 23 BOM Fort Hill Wharf recorded tide and residual tide; IMOS Darwin significant wave height and peak wave period 24 Near-bed turbidity box and whisker plot 28 PAR at -3 m LAT box and whisker plot 32 Near-bed water temperature time series plot for Darwin Harbour Inner and Darwin Outer sites 33 vii

8 Appendices Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Appendix H Appendix I Data Return Turbidity Data PAR Data Salinity and Water Temperature Data Chlorophyll-a Data Water Profile Data Water Sample Data Sediment Trap Data MODIS Satellite Imagery viii

9 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 westsouth-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 East Arm (EA) Dredging and Spoil Disposal Management Plans (DSDMP) (INPEX 2012) and GEP DSDMP (INPEX 2013). 1.2 Requirement to Monitor Water Quality The Project has approval for the removal of material from Darwin Harbour and disposal at an offshore spoil disposal site located approximately 12 km north-west of Lee Point (Figure 2-1). This process will mobilise sediments into the water column both at the dredge and spoil ground. Dredging and spoil disposal operations will mobilise sediments into the water column, increasing suspended sediment concentrations and sedimentation rates in broader areas due to re-suspension, dispersion and settling of the mobilised sediments. Of particular interest are the fine fractions of the mobilised sediment as these will remain in suspension longer than the coarser fractions. Suspended sediments have the potential to attenuate light, reducing pelagic and benthic primary production, and to increase sedimentation resulting in the smothering of sessile benthic organisms. Fluctuations in light and rates of sedimentation occur naturally in Darwin Harbour due to regular resuspension of particulate matter by the large tidal currents and storm events. However, dredging has potential to increase sedimentation and turbidity beyond the natural range and subsequently impact upon the health of sensitive receptors such as coral and seagrass. The DSDMP outlines the monitoring program designed to examine the potential impact on water quality from dredging and spoil disposal activities (INPEX 2012). The Nearshore Environmental Management Plan (NEMP) establishes the specific methodology and parameters for the monitoring program ( 2012a), summarised in Table 1-1. The objectives of the Water Quality and Subtidal Sedimentation Monitoring Program (WQSSMP) include: > Provide an early warning indicator of potential for impact on sensitive receptors due to deteriorating water quality; > Provide contextual water quality and subtidal sedimentation data in the investigations of recorded impacts on seagrass and corals; > Provide data on water quality to inform primary productivity monitoring and dredge model validation (mid to far-field); > The collection of water quality data that accounts for the spatial variability of turbidity typical for the macrotidal environment of the Harbour; > Continuation of current water quality program to improve understanding of the relationship between logger turbidity and sample suspended sediment concentrations (including at the Upper East Arm site); and > Monitoring of sedimentation rate. 1

10 Table 1-1 Data Type Summary of the WQSSMP Monitoring Method In-situ Near-Bed Measurements In-situ Near-Surface Measurements Water Profiles Water Profiles¹ (Primary Productivity) Water Samples Water Samples¹ (Primary Productivity) MODIS Satellite Imagery Sediment Traps Sediment Samples Turbidity, Photosynthetically Active Radiation (PAR), Conductivity, Temperature and Depth (CTD) sensors deployed approximately 1.0 m above the seabed at 15 sites. Data available in real-time or as logged data. Turbidity and Chlorophyll-a (Chl-a) sensors deployed approximately 1 m below the water surface at 5 sites. Data available as logged data only. Vertical water profiles taken at all 15 water quality monitoring sites, recording turbidity, PAR, CTD, Chl-a, ph and Dissolved Oxygen (DO). Vertical water profiles taken at 16 primary productivity sites in Middle Arm and East Arm, recording turbidity, PAR, CTD, Chl-a, ph and DO. Water sampling taken during servicing operations at each of the 15 monitoring stations. Near-surface and near-bed samples, analysed for Total Suspended Solids (TSS) and Particle Size Distribution (PSD). Water sampling taken during servicing operations at 4 primary productivity sites in Middle Arm and East Arm. Near-surface and near-bed samples, analysed for Turbidity, Chl-a, TSS, PSD, nutrients, metals and metalloids. MODIS satellite imagery for the Darwin Harbour region (including Spoil Ground) obtained as real colour images and translated into TSS. Two sediment traps installed at nine sites. Sediment samples analysed for dry inorganic weight, sedimentation rate and PSD. Sediment (grab) samples taken periodically alongside sediment traps, analysed for PSD. ¹ There is a requirement within the WQSSMP to collect water samples and vertical water profiles to inform the Primary Productivity Monitoring Program (PPMP); the results are presented in this report series but discussed in more detail in the PPMP Reactive and Informative Monitoring Programs The WQSSMP has been designed to incorporate both Reactive and Informative monitoring, defined as follows: > Reactive monitoring programs include triggers that initiate targeted monitoring, and adaptive and contingency management responses to manage impacts within the limits of acceptable loss; and > Informative monitoring programs are designed to measure environmental responses to dredging and spoil disposal activities, and provide contextual information on effects of sedimentation and turbidity on sensitive receptors. Reactive monitoring is carried out at four Impact sites by comparing daily-averaged turbidity data against pre-defined trigger values prescribed in the Triggered Action Response Plan (TARP) in the DSDMP (INPEX 2012). These include: > Channel Island (coral receptors); > Fannie Bay (seagrass receptors); > Lee Point (seagrass receptors); and > Woods Inlet (seagrass receptors). Informative monitoring is carried out at 11 Impact and Control sites to improve understanding of the spatial extent of dredge plume and associated impacts (if any). Data collected will be used for interpretative purposes and may support management decisions using a multiple lines of evidence approach, particularly where reactive triggers are exceeded and require a management response. 2

11 1.3 Purpose of this Report This report (Bimonthly Report 7 D7) provides an assessment of the water quality and an examination of potential dredging-related effects on water quality between 1 September 2013 and 31 October 2013, covering a period of 61 days. The report collates information from the WQSSMP, data provided by the Australian Bureau of Meteorology (BOM), the USA Atmospheric Radiation Measurement Climate Research Facility (ARM), and the USA National Aeronautics and Space Administration (NASA). 3

12 2 Methodology 2.1 External Sources of Information BOM Meteorological Data Weather data was obtained from the BOM weather station at Darwin Airport (BOM Reference ), including 30 minute records of wind speed, wind direction, air temperature, relative humidity, barometric pressure and precipitation. All received BOM data is summarised in Table 2-1 and Figure 2-1 presents the location of the monitoring station Water Level Data The BOM National Tidal Centre (NTC) maintains a tide gauge at Fort Hill Wharf that records water levels every five minutes. This gauge is the officially recognised site used to generate the tidal predictions for Darwin Harbour presented in the Australian Hydrographic Office annual Australian National Tide Tables publications. All received BOM data is summarised in Table 2-1, and Figure 2-1 presents the locations of the monitoring stations AUSWAVE Model Data Wave data during the reporting period was sourced from the Australian Bureau and shows significant wave height output from the BOM AUSWAVE model. A model output location has been selected which is approximately 11 km north-north-east of Charles Point (see Table 2-1 and Figure 2-1). The AUSWAVE model is based on version 3.14 of WAVEWATCH III. Operational runs are performed using surface wind data from the Australian Community Climate and Earth-System Simulator (ACCESS). This model has been developed and tested by research staff from the Centre for Australian Weather and Climate Research (CAWCR). The AUSWAVE model resolution is 0.1 degrees. Table 2-1 BOM data summary Site Name ID Location Parameters Frequency Darwin Airport AIR_ S E Fort Hill Wharf NTC_ S E Wind speed, wind direction, air temperature, relative humidity, barometric pressure, rainfall. Water levels. 30-min 5-min AUSWAVE Model Output Location Darwin WAV_ S E Significant wave height, peak wave period and peak wave direction. 180-min IMOS In order to avoid future periods of spurious data that occasionally affect the AIMS IMOS station, reported wave height from this report (D7) onwards will be based on BOM AUSWAVE model outputs, for the appropriate model output location corresponding to Darwin see Section and Table ARM The ARM Climate Research Facility was established in April 2002 in Darwin. The facility is situated adjacent to the BOM meteorological office near Darwin International Airport. Total Solar Irradiance is recorded every one minute, which is converted to and presented as PAR data within this report. Table 2-2 summarises all data received from ARM, and Figure 2-1 presents the location of the monitoring station. 4

13 Table 2-2 ARM data summary Site Name ID Location Parameters Frequency Darwin Airport AIR_ S E Best Estimate Global Downwelling Shortwave Hemispheric Irradiance 1-min NASA NASA Moderate-resolution Imaging Spectroradiometer (MODIS) satellite images provide a useful macroscale context to assist with the interpretation of spatial variability in turbidity measurements. In general, images are captured by the AQUA and TERRA satellites using the MODIS imaging system approximately twice a day. Cloud cover and reflection of sunlight affect image quality and may at times provide little or no coverage in the area of interest. The 250 m x 250 m pixel size also limits the value of these maps within Darwin Harbour where the pixel contamination by the coastal features and water depth affect quality. The satellite images were translated to TSS concentration maps by In-Situ Marine Optics (ISMO), and ten images were selected for presentation in Appendix I. The images were selected based on coverage and significance of observations, and are summarised in Table 2-3. Table 2-3 NASA data summary Figure ID Date and Time Tidal Cycle Tidal Phase Comments Figure I-1 3 September :40 Figure I-2 5 September :40 Figure I-3 8 September :30 Figure I-4 11 September :00 Figure I-5 20 September :55 Neap Flood Low turbidity during neap tides. Spring Ebb Elevated turbidity around the harbour entrance and outer harbour as spring ebb tide begins. Spring Ebb High turbidity throughout region with greater elevations of turbidity in the inner harbour and along the coast west of harbour. Spring Ebb Concentrated areas of high turbidity throughout the harbour region as a spring ebb tide begins. Spring Ebb High turbidity throughout the entire region during the ebb phase of a peak spring tide. Figure I-6 26 September :45 Figure I-7 6 October :55 Figure I-8 8 October :45 Figure I-9 22 October :55 Figure I October :35 Neap Ebb Low to moderate turbidity through the inner and outer harbour. Spring Ebb High turbidity levels throughout the inner and outer west harbour. Spring Ebb High turbidity levels in the harbour during a spring ebb tide. Spring Ebb Very high turbidity throughout inner harbour as ebb tide ends. Neap Slack Low Very low turbidity levels throughout region during a slack low tide in the neap cycle. 5

14 2.2 Monitoring Sites In-Situ Measurements Fifteen water quality monitoring sites were selected throughout Darwin Harbour. Table 2-4 and Table 2-5 summarise details for both reactive and informative sites, with three of these sites (Charles Point 1, East Point and Gunn Point) having been decommissioned in June 2013 to reflect the approved dry season sampling reduction. Table 2-6 provides a summary of monitoring site deployments, Figure 2-1 maps the locations of all sites, and Figure 2-2 further illustrates the timings of field activities plotted alongside water level. To describe measurements spatially, sites have been categorised into two distinct geographical areas: 1. Darwin Outer all sites north of, and including, the Mandorah (MAN_01) monitoring site; and 2. Darwin Harbour Inner all sites south of, but excluding, the Mandorah (MAN_01) monitoring site. Table 2-4 Summary of reactive water quality monitoring sites Site Name ID Function Method Parameters Dry Season Frequency Channel Island CHI_01 CORAL Logged and real-time Logged Turbidity, PAR Turbidity, Chl-a CTD 15-min logged 4-hour real-time 1 10-min logged 15-min logged Fannie Bay FAN_01 SEAGRASS Logged and real-time Turbidity, PAR 15-min logged 4-hour real-time 1 Logged CTD 15-min logged Lee Point LEE_01 SEAGRASS Logged and real-time Turbidity, PAR 15-min logged Telemetry Removed 1 Logged CTD 15-min logged Woods Inlet WOD_01 SEAGRASS Logged and real-time Logged Turbidity, PAR Turbidity, Chl-a CTD 15-min logged Telemetry Removed 1 10-min logged 15-min logged 1 Telemetry returned to 30-min real-time during servicing operations between 13 September 2013 to 17 September

15 Table 2-5 Summary of water quality monitoring sites Site Name ID Function Method Parameters Dry Season Frequency Casuarina Beach CAS_01 SEAGRASS Logged and real-time Turbidity, PAR 15-min logged Telemetry Removed 1 Logged TD Continuous (2 Hz) Charles Point (Site 1) CHP_01 SEAGRASS and CORAL Logged and real-time Turbidity, PAR Station Decommissioned Charles Point (Site 2) CHP_02 SEAGRASS and CORAL Logged and real-time Turbidity, PAR 15-min logged Telemetry Removed 1 Logged TD Continuous (2 Hz) East Point EAS_01 SEAGRASS Logged and real-time Turbidity, PAR Station Decommissioned Gunn Point GUN_01 SPOIL DISPOSAL Logged and real-time Turbidity, PAR Station Decommissioned Mandorah MAN_01 CORAL Logged and real-time Turbidity, PAR 15-min logged Telemetry Removed 1 Logged TD Continuous (2 Hz) Northeast Wickham Point NEW_01 CORAL Logged and real-time Logged Turbidity, PAR Turbidity, Chl-a TD 15-min logged Telemetry Removed 1 10-min logged Continuous (2 Hz) South Shell Island SSI_01 CORAL Logged and real-time Logged Turbidity, PAR Turbidity, Chl-a TD 15-min logged 4-hour real-time 1 10-min logged Continuous (2 Hz) Upper East Arm UEA_02 DREDGING Logged and real-time Turbidity, PAR, CTD 15-min logged Telemetry Removed 1 Weed Reef (Site 1) WED_01 CORAL Logged and real-time Logged Turbidity, PAR Turbidity, Chl-a CTD 15-min logged 4-hour real-time 10-min logged 15-min logged Weed Reef (Site 2) WED_02 CORAL Logged and real-time Turbidity, PAR 15-min logged 4-hour real-time 1 Logged CTD 15-min logged 1 Telemetry returned to 30-min real-time during servicing operations between 13 September 2013 to 17 September

16 Table 2-6 Deployment summary SiteID Location Service Date CAS_ 'S, 'E 13/09/ :05 16/10/ :19 CHI_ 'S, 'E 17/09/ :18 15/10/ :12 CHI_ 'S, 'E 17/09/ :49 12/10/ :35 CHP_ 'S, 'E 14/09/2013 9:00 (recommission) 12/10/ :58 30/10/ :29 CHP_ 'S, 'E 14/09/2013 9:34 12/10/2013 9:02 EAS_ 'S, 'E 17/09/ :57 (recommission) FAN_ 'S, 'E 13/09/ :50 15/10/ :35 FAN_ 'S, 'E 13/09/ :40 (recommission) 16/10/2013 7:46 (decommission) 30/10/ :00 (recommission) GUN_ 'S, 'E 16/10/2013 9:44 (recommission) LEE_ 'S, 'E 13/09/ :09 16/10/ :47 LEE_ 'S, 'E 13/09/ :57 (recommission) 16/10/ :08 (decommission) MAN_ 'S, 'E 14/09/ :07 15/10/ :19 NEW_ 'S, 'E 16/09/ :00 13/10/ :16 SSI_ 'S, 'E 16/09/ :31 13/10/ :05 UEA_ 'S, 'E 13/10/ :32 (recommission) 30/10/ :56 UEA_ 'S, 'E 16/09/2013 8:50 13/10/2013 9:58 (decommission) WED_ 'S, 'E 16/09/ :47 13/10/2013 7:47 30/10/2013 7:48 WED_ 'S, 'E 17/09/2013 8:21 15/10/2013 8:36 WOD_ 'S, 'E 14/09/ :47 12/10/ :02 WOD_ 'S, 'E 14/09/ :31 (recommission) 12/10/ :40 15/10/ :11 1 Additional contingency site deployed and serviced alongside reactive monitoring site (within 200 m). 8

17 Figure 2-1 In-situ water quality monitoring sites 9

18 Figure 2-2 Field operations summary Blue dots represent near-bed instrument servicing; blue-outer red-inner dots represent both near-bed and near-surface instrument servicing. Labels F31 to F33 are field trip references used within the data management system 10

19 Dataloggers and telemetry system Near-bed, real-time sensors (turbidity, PAR and CTD) are connected directly to a NexSens Submersible Datalogger (SDL500) fixed to the seabed mooring frame. The SDL500 is connected via a 20 m rubberjacketed communication cable to a NexSens Iridium Satellite Datalogger (SDL500-I) housed within a NexSens Coastal Data Buoy (CB-300) designed to accommodate the SDL500-I datalogger. The general configuration of the monitoring station is illustrated in Figure 2-3. Measured data is downloaded from the SDL500 during each servicing operation; this logged data is used for analysis and presented in this report. Real-time data is telemetered using Iridium satellite communications sent to the NexSens ichart software database. Real-time turbidity data (daily averaged) is assessed against the appropriate TARP trigger levels described in the DSDMP (INPEX 2012). Figure 2-3 Monitoring site configuration 11

20 Turbidity Turbidity is a measure of the degree to which water loses its transparency due to the presence of suspended particulates. Turbidity is measured using WET Labs ECO NTU and ECO FLNTU instruments. The ECO NTU instrument is fixed to the seabed frame in a downward-looking orientation approximately 1.0 m above the seabed and connected directly to the SDL500 datalogger and telemetry system. The FLNTU instrument is fixed horizontally to the surface buoy frame at approximately 0.5 m below the water surface. Both instruments are equipped with an integral wiper assembly (Bio-wiper) to prevent biological growth over the optical aperture PAR PAR designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. PAR is measured using WET Labs ECO PAR instruments. The ECO PAR instrument is fixed to the seabed frame in an upward-looking orientation approximately 1.15 m above the seabed and connected directly to the SDL500 datalogger and telemetry system Conductivity Conductivity is measured using the In-Situ Inc. AquaTROLL 200 instrument. The AquaTROLL 200 is fixed to the seabed frame at approximately 1.0 m above the seabed, connected directly to the datalogger and telemetry system. The instrument is equipped with an AquaTROLL Shield Antifouling System to reduce fouling of the associated sensors. Ocean salinity is generally defined as the salt concentration in sea water. Salinity is measured in Practical Salinity Units (PSU), which are derived from conductivity, temperature and depth. Supplementary installation was undertaken (at seven selected sites) of WET Labs MicroCAT SBE37SMP CTD loggers with serial interface, internal battery, non-volatile internal Flash Memory and anti-foulant devices on (pumped) inlet and outlet to minimise bio-fouling. Conductivity data is downloaded at each service. The MicoCATs are fixed to the central upright of the seabed mooring frame with 2 SS M8 bolts at a height of 700 mm above the seabed Temperature Water temperature is also measured using the AquaTROLL 200, connected directly to the datalogger and telemeter. Supplementary installation was undertaken of RBRduo TD (for all those sites without MicroCATs) loggers with USB interface, internal battery, and non-volatile internal Flash Memory. Temperature data is downloaded at each service. The RBRduos are secured within a vented Polyvinyl chloride (PVC) canister (to minimise bio-fouling) fixed to the central upright of the seabed mooring frame at a height of 400 mm above the seabed. Temperature data is also downloaded at each service from the MicroCAT SBE37SMP CTD or the RBRduo TD loggers Depth Absolute (non-vented) pressure is measured using a piezoresistive pressure sensor within the AquaTROLL 200, connected directly to the datalogger and telemetry system at approximately 1.0 m above the seabed. Depth (pressure) data is also downloaded at each service from the MicroCAT SBE37SMP CTD or the RBRduo TD loggers Chlorophyll-a Chl-a fluorescence is an indicator of active phytoplankton biomass and chlorophyll concentrations, and its measurement is used for tracking biological variability and abundance in the water column. Chl-a is measured using the WET Labs ECO FLNTU instrument. The instrument is fixed to the surface buoy frame at approximately 0.5 m below the water surface. It is equipped with an integral wiper assembly (Bio-wiper) to prevent biological growth over the optical aperture. 12

21 Details for each of the monitoring station sensors are presented in Table 2-7. Table 2-7 Monitoring station sensor specifications Sensor Parameter Range (units) WET Labs NTU WET Labs FLNTU Turbidity (near-bed) Turbidity (near-surface) 0 to 250 NTU 0 to 350 NTU WET Labs PAR PAR 0 to 6500 µmol m -2 s -1 In-situ AquaTROLL 200 Conductivity 0 to 100 ms/cm In-situ AquaTROLL 200 Temperature -5 to 50 C In-situ AquaTROLL 200 Depth (pressure) 0 to 100 psia WET Labs FLNTU Chl-a 0 to 125 µg/l WET Labs MicroCAT SBE37 Conductivity 0 to 70 ms/cm WET Labs MicroCAT SBE37 Temperature -5 to 35 C WET Labs MicroCAT SBE37 Depth (pressure) 0 to 45 psia RBRduo TD Temperature -5 to 35 C RBRduo TD Depth (pressure) 0 to 45 psia Water Profiles Vertical water profiles were collected using a Seabird SBE 19plus V2 CTD with turbidity, PAR, Chl-a, ph and DO sensors. The SBE 19plusV2 s scan rate of 2 Hz provides fine-scale measurement performance and recording endurance of up to 60 hours with 64 MB of flash memory. Details for each of the integrated sensors are presented in Table 2-8. Table 2-8 Water Profiler sensor specifications Sensor Parameter Range (units) Seabird SBE 3F Temperature -5 to 35 C Seabird SBE 4C Conductivity 0 to 9 S/m Digiquartz Pressure 0 to 200psia WET Labs EcoFLNTURT Turbidity 0 to 200 NTU Satlantic PAR PAR 0 to 4500 µmol photons m -2 s -1 WET Labs EcoFLNTURT Chl-a 0 to 75 µg/l Seabird SBE 18 ph 0 to 14 Seabird SBE 43 DO 120% of surface saturation WQSSMP Water profiling is completed at each of the fifteen in-situ water quality monitoring sites at monthly intervals (during planned servicing operations) for the duration of the Project. Water profiling was conducted between 11 September 2013 and 16 September 2013 and between 12 October 2013 and 16 October 2013; this is summarised in Table

22 Table 2-9 WQSSMP water profiling summary ID Location Dates Times Parameters CAS_ S 13 September :41 Turbidity, PAR, CTD, Chl-a, ph, DO E 16 October :02 CHI_ S 11 September :22 Turbidity, PAR, CTD, Chl-a, ph, DO E 15 October :52 CHI_ ' S 11 September :35 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 12 October :45 CHP_ ' S 14 September :19 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 12 October :08 CHP_ ' S 14 September :40 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 12 October :16 EAS_ ' S ' E 13 September :05 Turbidity, PAR, CTD, Chl-a, ph, DO FAN_ S 15 October :48 Turbidity, PAR, CTD, Chl-a, ph, DO E 13 September :19 GUN_ ' S ' E 16 October :53 Turbidity, PAR, CTD, Chl-a, ph, DO LEE_ S 13 September :20 Turbidity, PAR, CTD, Chl-a, ph, DO E 16 October :00 MAN_ ' S 14 September :15 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 15 October :28 NEW_ S 16 September :21 Turbidity, PAR, CTD, Chl-a, ph, DO E 13 October :31 SSI_ ' S 11 September :31 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 13 October :23 UEA_01 UEA_ ' S ' E ' S ' E 13 October :25 Turbidity, PAR, CTD, Chl-a, ph, DO 16 September :17 Turbidity, PAR, CTD, Chl-a, ph, DO WED_ S 11 September :24 Turbidity, PAR, CTD, Chl-a, ph, DO E 13 October :00 WED_ S 11 September :33 Turbidity, PAR, CTD, Chl-a, ph, DO E 15 October :51 WOD_ ' S 14 September :55 Turbidity, PAR, CTD, Chl-a, ph, DO ' E 12 October : PPMP No vertical profiling was required for the PPMP during this reporting period Water Samples WQSSMP Water samples are collected for analysis of TSS and PSD at eight selected water quality monitoring sites at monthly intervals (during planned servicing operations) for the duration of the Project. Water sampling was conducted alongside WQSSMP water profiling measurements between 11 September 2013 and 16 September 2013 and between 12 October 2013 and 16 October 2013; this is summarised in Table

23 Table 2-10 WQSSMP water sampling summary ID Location Dates Times 1 Analytes CHI_ S 11 September :22 TSS (MAFRL 2 ) E 15 October :52 PSD (MAA 3 ) FAN_ S 15 October : E 13 September :19 LEE_ S 13 September : E 16 October :00 NEW_ S 16 September : E 13 October :31 SSI_ ' S 11 September : ' E 13 October :23 UEA_01 UEA_ ' S ' E ' S ' E 13 October :25 16 September :17 WED_ S 11 September : E 13 October :00 WOD_ ' S 14 September : ' E 12 October :22 1 Water samples are collected alongside associated water profiling activities; all samples are collected within 10 minutes of stated time. 2 MAFRL: Marine and Freshwater Research Laboratory, Murdoch University, WA. 3 MAA: Microanalysis Australia, WA PPMP No water sampling was required for the PPMP during this reporting period Water Sampler Water samples were collected using a submersible pump and hose fixed to the SeaCAT SBE19plus V2 frame for manual deployment and retrieval. At each site samples were pumped from near-bed (approximately 1.0 m above seabed) and near-surface (approximately 1.0 m from water surface) directly into sample containers provided by the respective laboratories Sample Handling Each near-bed and surface sample was homogenised then separated into two 1 L samples for TSS filtration, and two 500 ml samples for PSD analysis. The TSS samples were prepared by vacuum filtering through pre weighed 45 µm glass filters in the workshop within 24 hours of collection. Filter papers were stored in sealed plastic sleeves and couriered to the MAFRL laboratory for determination of TSS. Water samples for PSD analysis were shipped as wet samples to the MAA laboratory. Water samples were handled in accordance with laboratory specified preservation methods, and transported under chain of custody (CoC) procedures in a timely manner to ensure sample integrity from collection to laboratory analysis Sediment Samples Sediment Traps Sediment samples were collected from sediment trap sites deployed at nine selected water quality monitoring sites. The traps consist of a 1 m length of PVC pipe with 50 mm diameter and a 100 mm catchment aperture. Two traps were deployed at the eight sites (East Point decommissioned during dry season) and fixed to the vertical protector bars on the seabed platform (Figure 2-3). 15

24 The sediment trap accumulation rate is measured using the Loss On Ignition (LOI) method at the Microanalysis laboratory. The sediment trap contents is flushed into a graduated cylinder at the workshop in Darwin using deionised water and allowed to settle for 24 hours. After settling, a portion of the clear water is decanted to allow the contents to be flushed into a 2 L sample bottle. The samples are chilled and sent to Microanalysis for analysis of the Total Dry Mass (TDM), Total Dry Inorganic Mass (TDIM) and particle sizing by laser diffraction (PSLD). Upon receipt of the samples, Microanalysis performs the PSLD analysis and returns the sub sample to the original sample. The entire contents are then dried at 105 C until a constant weight is achieved and the TDM is recorded. After this the entire contents are fired at 550 C until a constant weight is again achieved and the TDIM is recorded. The wet volume is recorded at the workshop in Darwin for completeness and backwards compatibility with previous wet volume sediment measurements. Table 2-11 Sediment trap summary ID Location Start Dates End Dates Duration (Days) Analytes CHI_01 FAN_01 LEE_01 NEW_01 SSI_01 WED_01 WED_02 WOD_ S E S E S E S E ' S ' E S E S E ' S ' E 16 August September August September August September August September August September August September August September August September Wet Volume measurement conducted by field team. 2 TDIM Total Dry Inorganic Mass (analysed by Microanalysis Australia). 17 September October September October September October September October September October September October September October September October Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Wet Volume 1 TDIM (MAA) 2 PSD (MAA) Sediment Grabs No sediment grabs were required during this reporting period Sample Handling On recovery the sediment traps were sealed and transported to the Laboratory where samples were processed for transit to the respective laboratories for analysis. Table 2-11 summarises the sediment trap deployments. 16

25 2.3 Additional Analysis Turbidity Empirical Model The empirical model relating turbidity to tidal range described in the WQSSMP Baseline Report (B1 December 2012) ( 2012b) has been applied to the Darwin Harbour Inner and Darwin Outer sites. The empirical model provides the relationship between daily average tidal range and daily average turbidity response. As discussed in B1, the tool effectively captures 80% to 90% of the tidally generated variability in daily average turbidity at the Darwin Harbour Inner sites, and hence provides a useful means to remove the tidal influence from the turbidity signal. The difference between the measured signal and the predicted turbidity is referred to as the turbidity residual. The variability in the turbidity residual may then be ascribed to other non-tidal processes such as wind stirring, wave stirring, terrestrial-runoff turbidity sources and, potentially, dredging operations. It is important to recognise that the predictive tool is derived from dry season data when the effects of rainfall runoff and extreme winds and waves are negligible. The tidal predictive tool provides a useful approach to separating the tidally driven turbidity signal from the other turbidity. It will be implemented to assist in removing the tidally-driven turbidity signal from the measurements and the remaining turbidity residual may then be assessed further to identify other forcing effects such as rainfall, waves, wind and influences from dredging operations. The potential turbidity response to natural forcing and dredging operations are further discussed in Section Light Extinction Coefficient Extinction coefficients were estimated from the ARM surface (at Darwin Airport) and near-bed PAR measurements at each time step when the bottom light was available. Variations in sensor depth (temporally or spatially) and measured turbidity makes assessment of the light regime difficult. Extinction coefficients are calculated from light intensity with consideration of measured depth and therefore normalise the derivative for comparisons to be made. The extinction coefficient was only estimated from data between 09:45 and 15:45 local time (09:00 to 15:00 solar time) as the angle of incidence affects the bottom sensor measurements outside of these hours. Light extinction is discussed further in Section TARP For the management of potential dredging impacts on corals and seagrass, a risk based environmental monitoring and management framework has been developed. The complete process from monitoring turbidity trigger exceedances to implementing management responses is described using a TARP. This is a three-tiered, pressure and response strategy based on environmental and biological indicators; with an escalating management response in accordance with escalating risk to coral and seagrass communities. A more detailed description of the monitoring and management framework is described in the EA and GEP DSDMPs (INPEX 2012, 2013); however, Table 2-12 summarises the Level 1 turbidity triggers applicable to the WQSSMP for both wet and dry seasons. 17

26 Table 2-12 Level 1 trigger summary Season and Receptor Intensity Trigger Duration Trigger Frequency Trigger WET Season: CORAL (1 November to 31 April) WET Season: SEAGRASS (1 November to 31 April) DRY Season: CORAL (1 May to 30 October) DRY Season: SEAGRASS (1 May to 30 October) >44 NTU >26 NTU over 7 consecutive days >63 NTU >52 NTU over 5 consecutive days >23 NTU >20 NTU over 4 consecutive days >17 NTU >13 NTU over 4 consecutive days >26 NTU >6 days per 7-day rolling period >52 NTU >5 days per 7-day rolling period >20 NTU >4 days per 7-day rolling period >13 NTU >3 days per 7-day rolling period 2.5 Data Management and Quality Control The Quality Control (QA/QC) processes applied are described in the WQSSMP B1 Report ( 2012b). 18

27 3 Dredging Operations The dredging program involves a number of dredge vessels including Backhoe Dredgers (BHD), Cutter Suction Dredger (CSD) and Trailing Suction Hopper Dredgers (TSHD), operating in different areas depending on water depths, bed material characteristics and the amount of material to be removed. The dredging campaign is divided into five Separable Portions (SP1 to SP5) that refer to the location and duration of specific dredging activities. The Separable Portions are summarised in Table 3-1 and presented in Figure 3-1. Dredging for the GEP commenced on 23 October 2013 with direct TSHD, Queen of the Netherlands. During the reporting period TSHD operations of high spots and pipeline channel dredging occurred along the GEP route between Mandorah and Weed Reef. No East Arm dredging operations were undertaken during the reporting period. East Arm dredging operations ceased prior to midnight on 30 April 2013 representing the end of Season One dredging. As of 30 April 2013 overall East Arm progress was approximately 43% of the proposed total to be removed during the dredging program. Table 3-1 ID SP1 SP2 SP3 SP4 SP5 Dredge footprint summary Separable Portion Separable Portion 1 - Module Offloading Facility (MOF) Separable Portion 2 - Jetty Pocket Separable Portion 3 - Berth Area Separable Portion 4 - Approach Channel, Berth Approach and Turning Area Separable Portion 5 - Walker Shoal 19

28 Figure 3-1 Dredging footprint 20

29 4 Results 4.1 External Sources of Information BOM Meteorological data Winds during the reporting period were generally from northerly and westerly sectors (as indicated on the wind rose in Figure 4-1), which is typical for the corresponding time of year in Darwin. Figure 4-2 shows that daily average winds were generally in the 12 to 20 km/hr range, with a notable wind event occurring on 26 October 2013, where winds of up to 60km/hr were recorded. A period of strong easterly winds was recorded from 1 September 2013 to 8 September Wind direction during the reporting period transitioned from the easterlies of the dry season to the westerlies more commonly experienced during the wet season. Figure 4-1 BOM Darwin Airport wind rose 21

30 Figure 4-2 BOM Darwin Airport wind speed and wind direction The continuation of the dry season meant that minimal rainfall was recorded during September Several notable rainfall events occurred in October marking the beginning of the wet season transition. Figure 4-3 shows that 18.2 mm were recorded on 4 October 2013, and 14.4 mm, 26.8 mm and 17.6 mm were recorded on 15 October 2103, 24 October 2013 and 26 October 2013, respectively. In total, September 2013 received 0.2 mm, below the September monthly average of 15.5 mm. October 2013 received 98.6 mm in total, which was above the October monthly average of 70.6 mm. Figure 4-3 BOM Darwin Airport rainfall; and ARM Darwin Airport PAR Air temperatures showed a steady increase throughout the reporting period. Figure 4-4 shows that mean daily temperatures increased from about 26 C to 29 C throughout the reporting period, with maximum temperatures ranging from 31 C to 36 C. Relative humidity remained steady throughout the reporting period. Daily average barometric pressure showed a decrease during the first three weeks of the reporting period, from approximately 1014 hpa to 1011 hpa, and remained steady thereafter. This is to be expected with the transition to the Darwin wet season. 22

31 Figure 4-4 BOM Darwin Airport air temperature, relative humidity and barometric pressure Water Level Data Recorded and predicted tide data at Fort Hill Wharf was obtained from the NTC. Recorded and residual (i.e. difference between recorded and predicted) water levels are presented as time series in Figure 4-5. This plot indicates that there were no significant surge events, with the predicted and recorded tides differing by less than 0.2 m for the majority of the reporting period. The NTC Fort Hill Wharf tide gauge experienced two periods of data loss during the reporting period. One was during the period of 7 September 2013 to 12 September 2013, and the other was during the period 19 October 2013 to 21 October The two largest daily tidal ranges during D7 were observed during spring tides between 21 September 2013 and 23 September 2013, and 7 October 2013 to 9 October 2013, with peak ranges of 6.7 m and 6.8 m, respectively AUSWAVE Model Data Figure 4-5 shows that significant wave height remained steady and low during D7, with reported daily average significant wave height generally less than 0.4 m. A period of increased waves occurred from 1 September 2013 to 8 September 2013 that was associated with strong easterly winds (see Figure 4-2), with daily average significant wave height peaking at 0.75 m on 5 September Reported daily average peak wave period was generally between 4 and 16 seconds. 23

32 Figure 4-5 BOM Fort Hill Wharf recorded tide and residual tide; IMOS Darwin significant wave height and peak wave period ARM obtained Best Estimate Global Downwelling Shortwave Hemispheric Irradiance data from the ARM Climate Research Facility. This data was then converted to PAR, as shown in Figure 4-3. This figure shows that Surface PAR data experienced a gradual increase during the reporting period, with PAR generally at or close to 40 mol/m 2 /day, with some decreases associated with rainfall events notable during October, particularly on 23 October 2013 with PAR of approximately 25 mol/m 2 /day recorded NASA The selected MODIS images have been converted to TSS coverage maps and are presented in Appendix I. With the cessation of the dredging program on 30 April 2013 and relatively calm metocean conditions during the reporting period, there were few notable observations from within the TSS imagery. There was no conspicuous evidence of higher-than-background TSS signals at either the dredging site or spoil ground locations throughout the reporting period. 24

33 4.2 In-Situ Measurements Turbidity Data Return Turbidity data return statistics have been generated for both near-bed and near-surface turbidity records; these are presented in Table 4-1 and Table 1-1, respectively. These data return statistics are calculated only for periods when the site was deployed; Table 2-6 includes details of site decommissioning and recommissioning during the reporting period. Although only logged data is utilised within the bimonthly report series, a comparison of the logged and telemetered datasets is included in Appendix A to indicate data loss associated with transmission of real-time data. This assessment differs from data return in that it is assessment of data received prior to the QA/QC process. Table 4-1 Logged near-bed turbidity data return ID Days of data Data Return Missing Data % Good 3 (%) 1 (%) 2 % Bad 4 CAS_ CHI_ CHI_ CHP_ CHP_ EAS_ FAN_ FAN_ GUN_ LEE_ LEE_ MAN_ NEW_ SSI_ UEA_ UEA_ WED_ WED_ WOD_ WOD_ Data logged from 1 September 2013 to 31 October Data missing described as delete (non-data) values or data missing due to sensor or datalogger failure. 3 Data received flagged to be GOOD or PROBABLY GOOD as defined within QA/QC procedures. 4 Data received flagged to be BAD or PROBABLY BAD as defined within QA/QC procedures. 25

34 Table 4-2 ID Logged near-surface turbidity data return Days of data Data Return (%) Missing Data (%) % Good % Bad CHI_ NEW_ UEA_ UEA_ WED_ WOD_ In general, data return at the near-bed sites was good with almost 100% data return at all sites, with the exception of the sites FAN_02, MAN_01 and WOD_02 which experienced instrument malfunctions over the periods between 8 October 2013 to 16 October 2013, 18 September 2013 to 15 October 2013, and 9 October 2013 to 27 October 2013, respectively. Sites at CHI_01, FAN_01, UEA_01, WED_02 and WOD_02 had 12.67%, 10.62%, 63.67%, 21.03% and 53.09% data flagged as Bad data, respectively. At all five sites, the data is suspected to have been compromised by fouling interfering with sensor wiper operation or obscuring the sensor face. Bad data is actively reduced through analysis of real-time data, the identification of potential issues and resolution on the following field service (e.g. biofouling, wiper malfunctions). Time-series for all near-bed sites are presented in Appendix B1. For the near-surface sites, data return was also good, with almost 100% data return at all sites. Of data returned, the CHI_01 site experienced intermittent data spikes (possibly attributable to bio-fouling) between 24 September 2013 and servicing operations on 15 October Time-series for all nearsurface sites are presented in Appendix B Results Near-bed turbidity statistics of the daily averages are summarised in Table 4-3, including mean, median, maximum, standard deviation (SD), and 25 th, 75 th and 90 th percentile data. Near surface statistics are summarised in Table 4-4. Turbidity data (at the near-bed sites) is presented as a box and whisker plot (Figure 4-6) for daily averaged data. The lower and upper limits of the box represent the 25 th and 75 th percentiles, respectively; the horizontal line represents the median, and the box notches the upper and lower 95% confidence levels about the median value. The whiskers extend to the minimum and maximum values defined for a normal distribution (set at three times the interquartile range about the median. Means of the daily averaged turbidity is indicated by a black dot. 26

35 Table 4-3 Near-bed turbidity statistics Percentile ID Mean NTU Median NTU Max NTU SD NTU 25th NTU 75th NTU 90th NTU No. of Daily Avg. Total no. of good samples CAS_ ,829 CHI_ ,169 CHI_ ,564 CHP_ ,407 CHP_ ,834 EAS_ ,869 FAN_ ,248 FAN_ ,533 GUN_ ,480 LEE_ ,824 LEE_ ,169 MAN_ ,131 NEW_ ,823 SSI_ ,833 UEA_ UEA_ ,965 WED_ ,824 WED_ ,712 WOD_ ,625 WOD_ Table 4-4 Near-surface turbidity statistics Percentile ID Mean NTU Median NTU Max NTU SD NTU 25th NTU 75th NTU 90th NTU No. of Daily Avg. Total no. of good samples CHI_ ,457 NEW_ ,720 UEA_ ,653 UEA_ ,055 WED_ ,656 WOD_ ,709 27

36 Figure 4-6 Near-bed turbidity box and whisker plot 28

37 Turbidity levels were generally low (<20 NTU) during this reporting period as would be expected for dry season processes. CAS_01 and GUN_01 recorded the lowest turbidity values and displayed the least variability, although GUN_01 was redeployed on 14 October 2013 and so is not representative of the full reporting period. Turbidity levels were generally as expected for tidally forced conditions; this is further described in the discussion in Section 5. Darwin Harbour Inner sites display characteristics which are more in-line with the tidally driven empirical model, with elevation in turbidity levels observed during spring cycles Near-Bed and Near-Surface Turbidity Comparison Time series and daily-averaged turbidity data (near-bed and near-surface) are plotted for each site in Appendix B1 and Appendix B2. For assessment of vertical structure, time-series plots of near-surface and near-bed measurements and scatter plots are presented in Appendix B3. A linear curve fit was applied to the data to derive the gradient, m, and y-intercept, b, for the linear relationship: y (near-surface turbidity) = m x (near-bed turbidity) + b For the six sites where near-bed and near-surface data were available the derived gradients, y-intercept and coefficient of determination (R 2 ) are provided in Table 4-5. Table 4-5 Correlation between near-bed and near-surface turbidity measurement ID Linear Relationship Coefficient of Determination (R 2 ) CHI_01 y = x NEW_01 y = x UEA_01 y = x UEA_02 y = x WED_01 y = x WOD_01 y = x The relatively high coefficient of determination for all sites suggests that during the reporting period there was a strong link between near-surface and near-bed turbidity. The average gradient across these sites suggests that typically the near-surface turbidity is about 70% of the near-bed turbidity, as expected in an environment with strong tidal currents TARP There were no Level 1 dry season trigger exceedances recorded between 1 September 2013 and 31 October

38 4.2.2 Photosynthetically Available Radiation Data Return There were minimal days of no PAR recorded over the reporting period, with all sites recording PAR on 100% of days (Table 4-6), with the exception of MAN_01 which recorded one day of zero total PAR on 22 October 2013, although a clear cause is not evident. Zero Total PAR days refer only to days with valid data where no light was recorded. Table 4-6 ID Near-bed total PAR data return Reporting Period Length Zero Total PAR Record Length Zero PAR Days Recorded PAR Days Days Days % % CAS_ CHI_ CHI_ CHP_ FAN_ LEE_ MAN_ NEW_ SSI_ UEA_ WED_ WED_ WOD_ Results Near-bed PAR (instantaneous and daily total) measurements are presented for all sites in Appendix C1. A significant factor to consider when assessing PAR data is depth of the PAR sensor in the water column. The PAR data collected represents near-bed PAR data, and so without normalising this near-bed PAR data to a common depth, direct comparison between sites are not reasonably quantified. Thus, in order to make direct comparisons between PAR at the sites, the near bed PAR data has been normalised to a nominal depth of -3 m Lowest Astronomical Tide (LAT) using the extinction coefficients described in Section Statistics based on daily totals of PAR at -3m LAT are summarised in Table 4-7, including mean, median, maximum, SD, 25 th, 75 th, and 90 th percentile data. This data is also presented as a box and whisker plot in Figure

39 Table 4-7 PAR statistics at -3 m LAT Percentile ID Mean mol/m2 /day Median mol/m2/ day Max mol/m2/ day SD mol/m2/ day 25th mol/m2/ day 75th mol/m2/ day 90th mol/m2/ day No. of Daily Avg. Total no. of good samples CAS_ ,451 CHI_ ,257 CHI_ ,380 CHP_ ,098 CHP_ ,454 EAS_ FAN_ ,305 FAN_ GUN_ LEE_ ,446 LEE_ MAN_ NEW_ ,451 SSI_ ,449 UEA_ UEA_ WED_ ,456 WED_ ,137 WOD_ ,385 WOD_

40 Figure 4-7 PAR at -3 m LAT box and whisker plot In general, higher levels of PAR were recorded at the Darwin Outer sites, which is consistent with observations in previous reporting periods. Total PAR at Darwin Harbour Inner sites WOD_01, NEW_01, UEA_01, UEA_02, SSI_01, and CHI_01 was low (75 th percentile <2 mol/m 2 /d) in comparison to WED_01 and WED_02 which displayed different characteristics to the other Darwin Harbour Inner sites. Higher values and higher variability were observed at WED_01 and WED_02, thus more aligned to observations at Darwin Outer sites. Total PAR dose at Darwin Outer sites was generally much higher, particularly for EAS_01, CAS_01 and GUN_01, where the mean daily dose for the reporting period was >6 mol/m 2 /day, although GUN_01 was redeployed on 14 October 2013 and so is not representative of the full reporting period. Although there are a number of factors to consider when assessing light data, it appears that PAR data is significantly influenced by suspended sediment concentration, which is driven primarily by the tidal cycle, specifically the water level during solar time of 09:45 to 15:45 (particularly at the Darwin Harbour Inner sites) Salinity and Water Temperature Salinity is derived from electrical conductivity and temperature measurements through application of an equation of state. The conductivity sensors are particularly prone to drift during prolonged deployments as biofouling gradually affects the electron transfer process across the sensor/water interface. CTDs were deployed at eight monitoring sites: CHI_01, FAN_01, LEE_01, UEA_01, UEA_02, WED_01, WED_02 and WOD_01. The recorded salinity data is presented in Appendix D in this report. Due to the relatively low rainfall levels throughout the reporting period, salinity remained fairly steady (approximately in the 34 to 36 PSU range) across the monitoring sites. Water temperature time series data for the aforementioned sites are presented in Appendix D. Time series data for the Darwin Harbour Inner sites CHI_01, NEW_01, UEA_02 and WED_01 and the Darwin Outer sites CHP_02, GUN_01, LEE_01 and MAN_01 are shown in Figure 4-8. Water temperature records showed a general decrease in water temperature during the first week of the reporting period (approximately 28ºC to 27ºC) followed by a general increase in temperature to the end (approximately 31ºC) of the reporting period. 32

41 Figure 4-8 Near-bed water temperature time series plot for Darwin Harbour Inner and Darwin Outer sites Chlorophyll-a Chl-a fluorescence data was collected primarily for utilisation within the PPMP (Appendix E). In general, Chl-a fluorescence levels were low (in the range of 2-3 mg/l) with no significant increases recorded. The Chl-a data has undergone rigorous QA/QC as data spikes occurred at various times across the sites. Data at CHI_01 experienced frequent data spikes from 1 September 2013 to instrument servicing on 17 September 2013 and again from 23 September 2013 to instrument servicing on 13 October 2013, possibly due to bio-fouling. Similarly, data at sites NEW_01 and WOD_01 experienced similar data issues from 10 September 2013 until servicing on 16 September 2013 and 1 September 2013 until servicing on 15 September 2013, respectively. 4.3 Water Profiles Vertical profiles of turbidity and salinity (Appendix F1 and Appendix F2, respectively) were collected at the water quality logger sites during neap tides between 11 September 2013 and 16 September 2013 and between 12 October 2013 and 16 October Total rainfall over the preceding five day period provides an indirect measure of the freshwater inflow to the system and the likelihood that salinity and turbidity gradients may be observed. According to estuarine flushing processes, whereby the freshwater supply causes dilution in salinity, the strongest salinity gradient should be observed between the upper reaches of East Arm (UEA_02 and UEA_01) and the Darwin Outer sites. The September period was marked by rainfall levels (0.2 mm) which were below the average recorded for previous years (15.5 mm) while in October the total rainfall received was 28.6 mm above the October monthly average (70.6 mm); there was one rainfall event in September 2013 and three events were recorded in October During field trip 31 (11 September 2013 to 16 September 2013), salinity increased to 35.5 PSU on average. Due to minimal supply of freshwater, the upper East Arm site had a high salinity of 36 PSU (Figure F2-1). Until 13 October 2013, the date of profile collection at Upper East Arm, only 18.2 mm of rainfall was recorded for the month of October. The low rainfall level prompted the salinity at Upper East Arm to increase to approximately 36.5 PSU. From field trip 31 (September 2013) to 33

42 field trip 32 (October 2013), the salinity for both the inner and outer sites increased by 0.5 PSU on average. The whole reporting period was distinguished by almost no salinity stratification at each site. Turbidity profiles (Appendix F1) for the same dates, as discussed above, highlight the influence of the winds and waves on the Darwin Outer sites. A relatively calm and dry period, demonstrated through the low and steady significant wave heights and wind speeds, prevailed from 1 September 2013 to 31 October Therefore, the turbidity profiles on both field trips (11 September 2013 to 16 September 2013 and 12 October 2013 to 16 October 2013) indicated a typical dry season structure with vertically well-mixed conditions and weak horizontal gradients associated with tidal currents. 4.4 Water Samples WQSSMP TSS and Turbidity Relationship Water samples collected from 14 June 2012 until 28 February 2013 have been analysed to define the relationship between these two variables. This relationship, with coefficient of determination (r 2 ) = 0.87 (n=162), is defined as: y (TSS) = 1.23 x (Turbidity) Water sampling, and subsequent analysis by the MAFRL laboratory, was continued as per the WQSSMP and is presented in Appendix G Particle Size Distribution Results from the PSD analysis conducted by the MAA laboratory are presented in Appendix G2. The UEA_01 site had the coarsest particles in suspension with median (D50) values ranging from to µm. WED_01 had the finest particles on average; with median values ranging from µm to µm. 4.5 Sediment Trap Samples Results from the deployed sediment traps are available for traps recovered in September 2013 and October 2013; the calculated sedimentation rates are summarised in Table 4-8 and Table 4-9 PSD sample results are presented in Appendix H. Sedimentation results for NEW_01 for October 2013 are not presented due to evidence of the sediment trap tipping during the deployment and being contaminated by bed sediments. Table 4-8 ID F31 (September 2013) - sedimentation trap results by total dry inorganic weight analysis Trap 1 Sedimentation (mg/cm 2 /day) Trap 2 Sedimentation (mg/cm 2 /day) Mean Sedimentation (mg/cm 2 /day) Standard Deviation Relative Standard Deviation CHI_ % FAN_ % LEE_ % NEW_ % SSI_ % WED_ % WED_ % WOD_ % 34

43 Table 4-9 ID F32 (October 2013) - sediment trap results by total dry inorganic weight analysis Trap 1 Sedimentation (mg/cm 2 /day) Trap 2 Sedimentation (mg/cm 2 /day) Mean Sedimentation (mg/cm 2 /day) Standard Deviation Relative Standard Deviation CHI_ % FAN_ % LEE_ % NEW_ SSI_ % WED_ % WED_ % WOD_ % 35

44 5 Discussion The first period of dredging operations within Darwin Harbour ceased on the 30 April 2013 with low intensity TSHD commencing for the GEP on 23 October 2013, therefore the sampling period covered in this report primarily represents the interim dry season phase between Season One and Two. There were no Level 1 dry season trigger exceedances recorded over the reporting period (1 September 2013 to 31 October 2013). 5.1 MetOcean Conditions The low total rainfall during September 2013 (<1 mm) and the increased frequency of significant daily rainfall totals through October 2013 (98.6 mm monthly total) indicates that this bimonthly period marks the transition from the dry to wet season. This is further indicated by a sustained reduction in atmospheric pressure from mid-september 2013 and a corresponding shift in the wind direction from the easterly to westerly sectors. Daily-averaged wind speed was typically 10 km hr -1. The observed rainfall, pressure and wind patterns during this reporting period match closely with those reported for the corresponding period last year. With significant wave height remaining well below 0.5 m, except for a short period in early September 2013, and the still modest amount of rainfall, the principal driver for turbidity variation in Darwin Harbour during this reporting period was the tide. Consequently, benthic light conditions were controlled by the tidal variations in turbidity and water level. The maximum and minimum tide ranges during the current reporting period were 6.4 m and 1.1 m, whereas in the corresponding reporting period last year they were 7.5 m and 0.4 m. The mean tide ranges, however, were similar between the two reporting periods (4.1 m to 4.2 m). The water temperature at inner and outer harbour sites displayed a consistent pattern of increase over the current reporting period; rising from a minimum of approximately 27 C on the 8 September 2013 to a maximum of approximately 31.5 at the end of the period. This pattern is similar to the one observed over the corresponding period last year when the water temperature increased over a similar range. 5.2 Turbidity During the current reporting period median daily-averaged near-bed turbidity levels were low across all sites (<6.5 NTU) and, overall, were representative of dry season conditions. Seventy fifth percentile values of daily-averaged turbidity were generally well below 10 NTU, except at Charles Point where the turbidity 75 th percentile was 14.5 NTU. In the corresponding period last year similar results were reported overall, although last year median daily-averaged turbidity at Charles Point 1 and 2 reached 9 NTU and 11 NTU. 75 th percentile values at Mandorah and Charles Point were also larger last year, reaching between 14 NTU and 22 NTU. During the current reporting period there is no clear pattern of significant differences in median turbidity between the Darwin Harbour Inner and Darwin Outer sites, which is typical of dry season conditions when the tide is the principal driver of turbidity patterns. Median turbidity at the exposed Darwin Outer site of Charles Point was generally higher than the other sites. 5.3 Turbidity Empirical Model Measured turbidity values were compared with predicted turbidity derived from the empirical turbidity model. As previously described, this model is based on pre-dredging dry season data and therefore provides a measure of the turbidity response to tidal stirring. The model can be used effectively to separate turbidity response to tidal stirring from other turbidity sources. Empirical model results for all sites are presented in Appendix B4 and include the following information: > Measured daily average turbidity, empirical turbidity prediction (plus the upper 95 th percentile confidence limit for the prediction); and 36

45 > Turbidity residual and preceding 14 day (time period selected to include both neap and spring tidal cycles) average turbidity residual. The magnitude of the turbidity residual across all sites was generally less than ±6 NTU and commonly less than ±3 NTU during the current reporting period. The largest spring tide range during the reporting period occurred on the 23 September 2013, which was the second largest spring tide range for During this spring tide, turbidity residuals at Fannie Bay and Northeast Wickham Point reached 10 NTU and 9 NTU, respectively. The latter was still within the 95% confidence interval of the model for that site. A turbidity residual of -10 NTU was reached at Charles Point on the following spring tide, which was of similar range and within the 95 % confidence interval of the model. During the intervening neap tide, the smallest tide range of 2013 occurred, resulting in small predicted and observed turbidity levels. The magnitudes of these isolated peaks in turbidity residual are considerably smaller than those reported during the wet season. For example, in the Bimonthly Water Quality and Subtidal Sedimentation Report 4 (1 March 2013 to 30 April 2013; 2013b), turbidity residuals were reported as reaching 20 NTU to 100 NTU and were attributed to elevated wave energy and terrestrial runoff events. The generally small turbidity residuals observed during the current sampling period (September 2013 to October 2013) are consistent with expectations for dry season months, where tidal stirring alone is the dominant driver of turbidity at all sites. 5.4 Benthic Light Bottom light (measured as PAR) measurements are presented in Appendix C1, and atmospheric irradiance (PAR) at the surface, bottom light and the estimated extinction coefficient are presented in Appendix C2. The latter was estimated from the surface solar irradiance (Darwin Airport), water depth above the sensor and near-bed PAR measurements at each time step when the bottom light was available. The extinction coefficient was only estimated from data between 09:45 and 15:45 local time (09:00 to 15:00 solar time). The bottom light measurements may also vary slightly between deployments as the depth of the sensor changes when the moorings are serviced. The amount of bottom light is influenced by both water depth and turbidity; larger depth and turbidity result in less light (and vice versa) due to absorption and scattering of light by suspended matter in the water. In order to normalise for depth variations between deployment and sites and thereby highlight the influence of turbidity, the PAR at -3 m LAT has been estimated at each site using the light extinction coefficient and its empirical relationship with turbidity (Table 4-7, Figure 4-7). The depth of -3 m LAT corresponds to typical occurrences of coral in Darwin Harbour and seagrass in Darwin Outer. During the period of September 2013 to October 2013, PAR at -3 m LAT at most of the Darwin Outer sites was significantly greater than at the Inner Harbour sites, particularly at East Point, Casuarina Point and Gunn Point where median PAR values were 6.5 to 7.0 mol/m 2 /day. In contrast, the Inner Harbour sites were characterised by median values in the range of 0.5 to 1.5 mol/m 2 /day, with the exception of Weed Reef, which had median values of approximately 2.5 mol/m 2 /day. This pattern of variability between sites is consistent with that observed in the corresponding period last year, as are the median quartile PAR magnitudes at most sites. There is, however, a reduction in the PAR at -3 m LAT at South Shell Island and Northeast Wickham compared to the corresponding period last year. The levels of light available to benthic communities during this monitoring period were consistent with those expected for dry season conditions, as monitored prior to commencement of the dredging program in

46 6 References (2012a). Ichthys Project Nearshore Environmental Monitoring Plan., August (2012b). Ichthys Project Nearshore Environmental Monitoring Program: Water Quality and Subtidal Sedimentation Baseline Report., December (2013a). Ichthys Project Nearshore Environmental Monitoring Program: Water Quality and Subtidal Sedimentation Bimonthly Report 1., January (2013b). Ichthys Project Nearshore Environmental Monitoring Program: Water Quality and Subtidal Sedimentation Bimonthly Report 4., June IMOS (2013). Sea Surface Wave Significant Height, accessed 1 October IMOS (2013). Peak Wave Period, accessed 1 October INPEX (2012). Dredging and Spoil Disposal Management Plan East Arm. INPEX Operations Australia Pty Ltd. INPEX (2013). Dredging and Spoil Disposal Management Plan Gas Export Pipeline. INPEX Operations Australia Pty Ltd. 38

47 Ichthys Nearshore Environmental Monitoring Program APPENDIX A DATA RETURN

48 Table A-1 Logged and Telemetered Data Return Statistics LOGGED TELEMETERED ID Expected Return % Return Expected Return % Return Difference CAS_ CHI_ CHI_ CHP_ CHP_ EAS_ FAN_ FAN_ GUN_ LEE_ LEE_ MAN_ NEW_ SSI_ UEA_ UEA_ WED_ WED_ WOD_ WOD_

49 Ichthys Nearshore Environmental Monitoring Program APPENDIX B TURBIDITY DATA

50 APPENDIX B1 Near-Bed Turbidity

51 Figure B1-1

52 Figure B1-2

53 Figure B1-3

54 Figure B1-4

55 Figure B1-5

56 Figure B1-6

57 Figure B1-7

58 Figure B1-8

59 Figure B1-9

60 Figure B1-10

61 Figure B1-11

62 Figure B1-12

63 Figure B1-13

64 Figure B1-14

65 Figure B1-15

66 Figure B1-16

67 Figure B1-17

68 Figure B1-18

69 Figure B1-19

70 Figure B1-20

71 APPENDIX B2 Near-Surface Turbidity

72 Figure B2-1

73 Figure B2-2

74 Figure B2-3

75 Figure B2-4

76 Figure B2-5

77 Figure B2-6

78 APPENDIX B3 Near-Bed and Near-Surface Turbidity Comparisons

79 Figure B3-1

80 Figure B3-2

81 Figure B3-3

82 Figure B3-4

83 Figure B3-5

84 Figure B3-6

85 APPENDIX B4 Turbidity Empirical Model

86 Figure B4-1

87 Figure B4-2

88 Figure B4-3

89 Figure B4-4

90 Figure B4-5

91 Figure B4-6

92 Figure B4-7

93 Figure B4-8

94 Figure B4-9

95 Figure B4-10

96 Figure B4-11

97 Figure B4-12

98 Ichthys Nearshore Environmental Monitoring Program APPENDIX C PAR DATA

99 APPENDIX C1 Near-bed PAR

100 Figure C1-1

101 Figure C1-2

102 Figure C1-3

103 Figure C1-4

104 Figure C1-5

105 Figure C1-6

106 Figure C1-7

107 Figure C1-8

108 Figure C1-9

109 Figure C1-10

110 Figure C1-11

111 Figure C1-12

112 Figure C1-13

113 Figure C1-14

114 Figure C1-15

115 Figure C1-16

116 Figure C1-17

117 Figure C1-18

118 Figure C1-19

119 Figure C1-20

120 APPENDIX C2 Light Extinction

121 Figure C2-1

122 Figure C2-2

123 Figure C2-3

124 Figure C2-4

125 Figure C2-5

126 Figure C2-6

127 Figure C2-7

128 Figure C2-8

129 Figure C2-9

130 Figure C2-10

131 Figure C2-11

132 Figure C2-12

133 Figure C2-13

134 Figure C2-14

135 Figure C2-15

136 Figure C2-16

137 Figure C2-17

138 Figure C2-18

139 Figure C2-19

140 Figure C2-20

141 Ichthys Nearshore Environmental Monitoring Program APPENDIX D SALINITY AND WATER TEMPERATURE DATA 1

142 Figure D1

143 Figure D2

144 Figure D3

145 Figure D4

146 Figure D5

147 Figure D6

148 Figure D7

149 Figure D8

150 Ichthys Nearshore Environmental Monitoring Program APPENDIX E CHLOROPHYLL-A DATA 1

151 Figure E1

152 Figure E2

153 Figure E3

154 Figure E4

155 Figure E5

156 Figure E6

157 Ichthys Nearshore Environmental Monitoring Program APPENDIX F WATER PROFILE DATA

158 APPENDIX F1 Turbidity Spatial Comparisons (WQSSMP)

159 Figure F1-1

160 Figure F1-2

161 APPENDIX F2 Salinity Spatial Comparisons (WQSSMP)

162 Figure F2-1

163 Figure F2-2

164 APPENDIX F3 Independent Water Profiles (WQSSMP) 11 September 2013 to 16 September 2013

165 Figure F3-1

166 Figure F3-2

167 Figure F3-3

168 Figure F3-4

169 Figure F3-5

170 Figure F3-6

171 Figure F3-7

172 Figure F3-8

173 Figure F3-9

174 Figure F3-10

175 Figure F3-11

176 Figure F3-12

177 Figure F3-13

178 Figure F3-14

179 Figure F3-15

180 APPENDIX F4 Independent Water Profiles (WQSSMP) 12 October 2013 to 16 October 2013

181 Figure F4-1

182 Figure F4-2

183 Figure F4-3

184 Figure F4-4

185 Figure F4-5

186 Figure F4-6

187 Figure F4-7

188 Figure F4-8

189 Figure F4-9

190 Figure F4-10

191 Figure F4-11

192 Figure F4-12

193 Figure F4-13

194 Figure F4-14

195 Figure F4-15

196 Ichthys Nearshore Environmental Monitoring Program APPENDIX G WATER SAMPLE DATA

197 APPENDIX G1 TSS Water Samples (WQSSMP)

198 Table G1-1 24/09/2013 (F31) TSS Site mg/l (Reporting Limit <0.5) CHI 01-T1 14 CHI 01-B1 15 FAN 01-T1 3.0 FAN 01-B1 3.8 LEE 01-T1 1.7 LEE 01-B1 2.6 NEW 01-T1 1.7 NEW 01-B1 3.3 SSI 01-T1 7.4 SSI 01-B1 10 UEA 01-T1 2.7 UEA 01-B1 3.0 WED 01-T1 7.6 WED 01-B1 7.5 WOD 01-T1 2.0 WOD 01-B1 4.5

199 Table G1-2 16/08/2013 (F30) - TSS Site mg/l (Reporting Limit <0.5) CHI 01-T1 3 CHI 01-T2 3 CHI 01-B1 6 CHI 01-B2 3 FAN 01-T1 3 FAN 01-T2 2 FAN 01-B1 2 FAN 01-B2 2 LEE 01-T1 2 LEE 01-T2 - LEE 01-B1 3 LEE 01-B2 - NEW 01-T1 4 NEW 01-T2 5 NEW 01-B1 4 NEW 01-B2 6 SSI 01-T1 4 SSI 01-T2 3 SSI 01-B1 3 SSI 01-B2 4 UEA 01-T1 4 UEA 01-T2 3 UEA 01-B1 4 UEA 01-B2 4 WED 01-T1 2 WED 01-T2 3 WED 01-B1 3 WED 01-B2 3 WOD 01-T1 6 WOD 01-T2 - WOD 01-B1 7 WOD 01-B2 -

200 APPENDIX G2 PSD Water Samples (WQSSMP)

201 Table G2-1 24/09/2013 (F31) PSD Site D10 (um) D50 (um) D90 (um) CHI 01 - T CHI 01 - T CHI 01 - B CHI 01 - B FAN 01 - T FAN 01 - T FAN 01 - B FAN 01 - B LEE 01 - T LEE 01 - T LEE 01 - B LEE 01 - B NEW 01 - T NEW 01 - T NEW 01 - B NEW 01 - B SSI 01 - T SSI 01 - T SSI 01 - B SSI 01 - B UEA 01 - T UEA 01 - T UEA 01 - B UEA 01 - B WED 01 - T WED 01 - T WED 01 - B WED 01 - B WOD 01 - T WOD 01 - T WOD 01 - B WOD 01 - B

202 Table G2-2 15/10/2013 (F32) PSD Site D10 (um) D50 (um) D90 (um) CHI 01 - T CHI 01 - T CHI 01 - B CHI 01 - B FAN 01 - T FAN 01 - T FAN 01 - B FAN 01 - B LEE 01 - T LEE 01 - T LEE 01 - B LEE 01 - B NEW 01 - T NEW 01 - T NEW 01 - B NEW 01 - B SSI 01 - T SSI 01 - T SSI 01 - B SSI 01 - B UEA 01 - T UEA 01 - T UEA 01 - B UEA 01 - B WED 01 - T WED 01 - T WED 01 - B WED 01 - B WOD 01 - T WOD 01 - T WOD 01 - B WOD 01 - B

203 Ichthys Nearshore Environmental Monitoring Program APPENDIX H SEDIMENT SAMPLE DATA

204 Table H-1 24/09/2013 (F31) Sediment Trap PSD Site D10 (um) D50 (um) D90 (um) CHI 01-S CHI 01-S EAS 01-S EAS 01-S FAN 01-S FAN 01-S LEE 01-S LEE 01-S NEW 01-S NEW 01-S SSI 01-S SSI 01-S WED 01-S WED 01-S WED 02-S WED 02-S WOD 01-S WOD 01-S Sediment trap samples were not subsampled from Field Trip 26 onwards, as outlined in Section Site EAS_01 not deployed during the dry season.

205 Table H-2 15/10/2013 (F32) Sediment Trap PSD Site D10 (um) D50 (um) D90 (um) CHI 01-S CHI 01-S EAS 01-S EAS 01-S FAN 01-S FAN 01-S LEE 01-S LEE 01-S NEW 01-S NEW 01-S SSI 01-S SSI 01-S WED 01-S WED 01-S WED 02-S WED 02-S WOD 01-S WOD 01-S Site EAS_01 not deployed during the dry season. 2 Suspected tipping of the sediment trap during deployment, thus results not reported

206 Ichthys Nearshore Environmental Monitoring Program APPENDIX I MODIS SATELLITE IMAGERY

207 Figure I-1 DRW_2013_09_03_1440_Aqua_TSS: Low turbidity during neap tides