2126628-REP Indigo Central EIA KD Working
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Appendix B – Marine Ecology This appendix has been prepared in support of an environmental assessment for the Indigo Central cable system, and should be read in conjunction with: Environmental Impact Assessment Report Appendix A – Physical Environment Appendix C – Other Existing Environmental Considerations Appendix D – Environmental Risk Assessments Appendix E – PMST Reports GHD | Report for Alcatel Submarine Networks - Indigo Central, 2126628 | 1 Table of contents B. Appendix B - Mainland Australian (Perth) to EEZ Exit ......................................................... 1 B.1 Habitat Overview.................................................................................................. 1 B.2 Nearshore Habitats and Associated Communities ..................................................... 1 B.3 Offshore Habitats ................................................................................................. 7 B.4 Matters of National Environmental Significance....................................................... 12 B.5 Other Protected Matters ...................................................................................... 40 B.6 Sensitive Time Windows ..................................................................................... 44 B. EEZ Entrance to Mainland Australia (Sydney) ................................................................. 46 B.7 Overview .......................................................................................................... 46 B.8 Offshore Habitats ............................................................................................... 48 B.9 Nearshore Habitats and Associated Communities ................................................... 54 B.10 Matters of National Significance ........................................................................... 58 B.11 Other Protected Matters ...................................................................................... 94 B.12 Sensitive Time Windows ..................................................................................... 99 References ........................................................................................................................100 Table index Table B-1 KEFs that intersect proposed cable route from Perth to EEZ ........................................ 13 Table B-2 Threatened Marine Mammals – Mainland Australian (Perth) to EEZ exit ........................ 16 Table B-3 Threatened Marine Reptiles – Mainland Australian (Perth) to EEZ exit........................... 19 Table B-4 Threatened Sharks – Mainland Australian (Perth) to EEZ exit....................................... 21 Table B-5 Threatened Birds – Mainland Australian (Perth) to EEZ exit ......................................... 22 Table B-6 Listed Migratory Species – Mainland Australian (Perth) to EEZ..................................... 29 Table B-7 Summary of ecologically sensitive timeframes (Perth to EEZ exit) ................................. 45 Table B-8 KEFs that intersect proposed cable route from Perth to EEZ ........................................ 61 Table B-9 Threatened Marine Mammals – EEZ entrance to Australian mainland (Sydney) .............. 66 Table B-10 Threatened Marine Reptiles – EEZ entrance to Australian mainland (Sydney)............... 68 Table B-11 Threatened Fish –EEZ entrance to Australian mainland (Sydney) ............................... 69 Table B-12 Threatened Marine Birds – EEZ entrance to Australian mainland (Sydney) ................... 71 Table B-13 Listed Migratory Species – Mainland Australian EEZ (Sydney).................................... 80 Table B-14 Summary of ecologically sensitive timeframes (Sydney to EEZ exit) ............................ 99 GHD | Report for Alcatel Submarine Networks - Indigo Central, 2126628 | iii Figure index Figure B-1 Indigo Central cable route from Perth to the EEZ exit ................................................... 3 Figure B-2 WA State marine protected areas and the Central cable route ....................................... 6 Figure B-3 Marine bioregions (DEWHA, 2008a) and the Central cable route from Perth to the EEZ exit.............................................................................................................. 8 Figure B-4 KEFs and the Central cable route from Perth to the EEZ exit....................................... 14 Figure B-5 Known location of Australian sea-lion breeding colonies (taken from Rogers et al., 2013) ............................................................................................................... 18 Figure B-6 Coastal aggregation areas for the southern right whale (taken from DSEWPC, 2012a).............................................................................................................. 18 Figure B-7 Tracks of three tagged southern right whales in 2014 (taken from Mackey et al., 2015) ............................................................................................................... 18 Figure B-8 Commonwealth marine protected areas and the Central cable corridor from Perth to the EEZ exit ................................................................................................... 43 Figure B-9 Marine bioregions (DEWHA, 2008a) and the Central cable route from the EEZ entrance to Sydney ............................................................................................ 47 Figure B-10 Central cable route through Tasmanian coastal waters ............................................. 55 Figure B-11 Matters of National Environmental Significance - SSPZ ............................................ 60 Figure B-12 KEFs and the Central cable route from EEZ entrance to Sydney ................................ 62 Figure B-13 Posidonia australis and other seagrass meadows .................................................... 65 Figure B-14 Commonwealth marine protected areas and the Central cable route from the EEZ entrance to Sydney...................................................................................... 97 GHD | Report for Alcatel Submarine Networks - Indigo Central, 2126628 | iv B. Appendix B - Mainland Australian (Perth) to EEZ Exit B.1 Habitat Overview The habitats described within this Section are those present within the mainland Australian Exclusive Economic Zone (EEZ) at the Perth end of the cable corridor – hereafter referred to as the Perth EEZ corridor reflective of the connection point. The cable will connect via an existing submarine Pop out Point (POP) within the Perth submarine cable Protection Zone (PZ). That POP is located approximately 1 km offshore in 10 m water depth. Figure B-1 illustrates that the cable then travels roughly west, then south around the Cape over the Naturaliste Trough, and then turns to the east and out of Australian waters. The cable leaves the EEZ approximately 430 km offshore, in a water depth of 5708 m (Figure B-1). From the POP point, where required and appropriate, the cable will be ploughed or water jetted into the seabed along the corridor up to water depth of 1000 m. Following this the cable will be placed on the open seabed. The cable route has a maximum width of 10 m, with the area of actual seabed disturbance comprising a small portion of this area. The cable route will transect or lie in proximity to a range of marine habitats including subtidal rocky reef, macroalgal beds, seagrasses and expanses of subtidal sand and soft sediments. The following sections provide a description of the nearshore and offshore habitats within the Perth EEZ corridor. Impacts to these habitats and associated species from the Project activities are assessed as part of the Ecological Risk Assessment in accordance with the Environment Protection and Biodiversity Conservation (EPBC) Act significant impact guidelines (refer Appendix D), and using the Protected Matters Search Tool (PMST). The area applied for the PMST used the route of the proposed cable in the Perth EEZ, with a 10 km buffer area. This search area is referred to throughout this assessment as the ‘cable corridor’ to distinguish the 10 km area for assessment from the 10 m wide cable installation route. B.2 Nearshore Habitats and Associated Communities B.2.1 Rocky Reef There are extensive areas of subtidal rocky reefs in the Perth region (Perth NRM, 2015) that support a wide diversity of algae and invertebrates, which in turn provide habitat and prey for many fish (Dye, 2009). Rocky reefs are largely dominated by macroalgal beds (refer following section) but also support a wide variety of sponges, corals, echinoderms, molluscs and crustaceans, including commercially important species such as the Western Rock Lobster (Panulirus cygnus). In the Perth region rocky subtidal reefs typically form linear structures. The Integrated Marine and Coastal Regionalisation of Australia (IMCRA v.4.0) distinguish the bioregion as the ‘Southwest Shelf Transition’ (DEWHA, 2008a). This bioregion is characterised as having shelf habitat bisected by distinctive ridges of limestone reef that supports patchy macroalgae and coral. Between the ridges may be areas of soft sandy or silty sediment that support diverse infauna, and possible areas of seagrass (Director of National Parks, 2013) (refer following sections). GHD | Report for Alcatel Submarine Networks - Indigo Central, 2126628 | 1 These linear reefs rise 10–20 m above the sea bed, in water depths of around 10–30 m and mostly lie parallel to the shoreline (Brooke et al., 2008). Although there are numerous reefal