In partnership with: Greater Sydney Local Land Services Office of Environment and Heritage Sydney Institute of Marine Sciences Council of the City of Sydney Sydney Harbour Estuary Processes Study Greater Sydney Harbour Coastal Management Program Stage 2 Detailed Studies of Vulnerabilities and Opportunities www.lls.nsw.gov.au Published by the Local Land Services Title: Sydney Harbour Estuary Processes Study Subtitle: Greater Sydney Harbour Coastal Management Program Stage 2 Detailed Studies of Vulnerabilities and Opportunities First published June 2018 ISBN More information Dr Peter Freewater, Office of Environment and Heritage Please cite as: Freewater, P. (2018) Sydney Harbour Estuary Processes Study - Stage 2 Detailed Studies of Vulnerabilities and Opportunities. Report prepared for Greater Sydney Local Land Services, June 2018. Acknowledgments This project was only possible because of the collaborative funding partnerships that Greater Sydney Local Land Services (GS LLS) established with the NSW Office of Environment and Heritage (OEH); Sydney Water; NSW Roads and Maritime Services; the Sydney Institute of Marine Sciences (SIMS); and 11 local government authorities (i.e. Inner West, City of Sydney, Blacktown, Parramatta, Strathfield, Canada Bay, Ryde, Ku-ring-gai, Northern Beaches, Lane Cove and Woollahra). Acknowledgement and gratitude to members of the Expert Panel (Karen Astels – NSW DPI, Lisa Currie - Council of the City of Sydney, Gavin Birch – University of Sydney, Geoff Whithycombe - SCCG, Kate Daffron - SIMS, Mark Millington – RMS, Martina Doblin – UNSW, Peter Scanes – OEH, Rodney Kerr – Sydney Water, Sadeq Zaman – Inner West Council, Sarah Clift – PRCG, Gus Pelosi and Tim Macdonald – OEH). Appreciation to Daylan Cameron and his team at OEH; and to Robert Adam and staff at GS LLS for ongoing support. (Cover photo www.mattkemp.com). All other photographs of Sydney Harbour marine-life have been provided by David Harasti. Peter Freewater has prepared this document on behalf of Greater Sydney Local Land Services with financial assistance from the NSW Government through its Estuary Management Program. This document does not necessarily represent the opinions of the NSW Government or the Office of Environment and Heritage. [GS-1551-24] © State of New South Wales through Local Land Services, 2018. Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing June 2018. However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Local Land Services or the user’s independent adviser. ii EXECUTIVE SUMMARY This report represents the culmination of seven years of collaborated research into Sydney Harbour that began with the development of the Sydney Harbour Catchment Water Quality Improvement Plan. The report contributes to Stage 2 of the coastal management program (Detailed Studies of Vulnerabilities and Opportunities) to fill gaps in current knowledge about the coastal management issues affecting Sydney Harbour. The information provided by these studies is to support decision-making and assist communities to understand these coastal management issues. This will enable actions to be developed to address those issues including current and future risks, as well as to promote public access, use and enjoyment of the Harbour and support the continued prosperity of the NSW economy. The improved knowledge generated by these studies will help support the identification, evaluation and selection of appropriate management actions required to address management issues in an integrated and strategic manner during Stage 3. This includes actions to support ecologically sustainable development, manage and reduce risks from coastal hazards, promote public access, improve community awareness and understanding, and support the well-being of the local community and coastal ecosystems. These studies will build on the history of Sydney Harbour including biophysical, demographic, infrastructure and economic changes, and how community aspirations have changed over time. It includes an assessment of threats and opportunities that concentrates primarily on threats to environmental assets and represents a preliminary analysis of the sorts of considerations that may need to be taken into account when considering future management initiatives for Australia’s most iconic waterway. Very high threats to environmental values were considered likely to result from the full range of climate change stressors, from habitat damage caused by anchoring and mooring, from increased inputs of nutrients and sediments from the surrounding and largely urbanised subcatchments, from toxic pollutants (including legacy pollutants in sediments) and from some aspects of fishing (notably illegal fishing and the discarding of unwanted catch). Many of these activities are likely to also impinge on social and economic values, because Sydneysiders consider the ecological health and aesthetic nature of the Harbour as fundamental to the appreciation and enjoyment of the Harbour and its surrounding foreshore, by residents and visitors alike. Opportunities to address these very high threats, and many of the lesser threats also identified, will require a carefully considered and coordinated response from all those responsible for managing various aspects of the Harbour and its surrounding catchment. Some of those opportunities have been scoped out in this report, but they are intended to be indicative rather than exhaustive. They are provided to inform Stage 3 of the Greater Sydney Harbour Coastal Management Program process. Six Spined Leatherjacket (Meuschenia freycineti) at Bare Island SYDNEY HARBOUR ESTUARY PROCESSES STUDY | Stage 2 Detailed Studies of Vulnerabilities and Opportunities iii Glossary of Acronyms ARI Average Recurrence Interval BMA Benthic Micro-Algae CALD Culturally and Linguistically Diverse CAPER DSS Catchment Planning and Estuary Response Decision Support System CPEM Catchment Pollutant Export Model DPI Department of Primary Industries DSS Decision Support System EFM Environmentally Friendly Mooring EPA Environmental Protection Authority GS LLS Greater Sydney Local Land Services GTP Gross Pollutant Trap ISQG-H Interim Sediment Quality Guideline-High LGA Local Government Authority MEMA Marine Estate Management Authority MPA Marine Protected Area N Nitrogen NIS Non-Indigenous Species OC Organic Carbon OEH NSW Office of Environment and Heritage OM Organic Matter P Phosphorous PAH Polycyclic Aromatic Hydrocarbon PEM Pollutant Export Model POP Persistent Organic Pollutant PPCP Pharmaceuticals and Personal Care Products RFH Recreational Fishing Haven RMS NSW Roads and Maritime Services SHERM Sydney Harbour Ecological Response Model SHEPS Sydney Harbour Estuary Processes Study SHCWQIP Sydney Harbour Catchment Water Quality Improvement Plan SIMS Sydney Institute of Marine Science SMCMA Sydney Metropolitan Catchment Management Authority TBT Tributyltin TN Total Nitrogen TOC Total Organic Carbon TP Total Phosphorous TSS Total Suspended Solids WSUD Water Sensitive Urban Design Anemone Hermit Crab (Dardanus pedunculatus) SYDNEY HARBOUR ESTUARY PROCESSES STUDY | Stage 2 Detailed Studies of Vulnerabilities and Opportunities iv Foreword The Sydney Harbour Estuary Processes Study (SHEPS) was developed to provide detailed studies of physical, ecological and biogeochemical processes of the Harbour. The study area encompasses the entire estuary and its drainage catchment with linkages to the Tasman Sea. It comprises the tidal waterway, foreshore and adjacent land of Sydney Harbour, including the entrance area and tidal tributaries covering the whole region of Sydney Harbour and associated tributaries and catchments. These studies aim to fill gaps in current knowledge about the coastal management issues affecting the Harbour and contributes to Stage 2 of the new coastal management program process. The information provided by these studies is to support council decision-making and assist communities to understand these coastal management issues. This will enable actions to be developed to address those issues including current and future risk from coastal hazards, as well as to promote public access, use and enjoyment of the coast and support the continued prosperity of the NSW economy. The improved knowledge generated by these studies will help support the identification, evaluation and selection of appropriate management actions required to address coastal management issues in an integrated and strategic manner during Stage 3. (OEH, 2015). This project was only possible because of the collaborative funding partnerships that the then Sydney Metropolitan Catchment Management Authority (now Greater Sydney Local Land Services (GS LLS)) established to develop the Sydney Harbour Catchment Water Quality Improvement Plan (Freewater and Kelly, 2015). Partners included the 16 local government authorities that were within the Sydney Harbour catchment (i.e. Auburn, Ashfield, City of Sydney, Blacktown, Parramatta, Holroyd, Strathfield, Canada Bay, Ryde, Ku-ring-gai, Manly, Lane Cove, Woollahra, Leichhardt, Marrickville and Burwood); the NSW Office of Environment and Heritage (OEH); Sydney Water; and NSW Roads and Maritime Services and Sydney Institute for Marine Sciences (SIMS). These partnerships continued under the leadership of GS LLS. SIMS has either provided or contributed to all