Sydney Harbour A systematic review of the science 2014 Sydney Institute of Marine Science Technical Report The Sydney Harbour Research Program © Sydney Institute of Marine Science, 2014 This publication is copyright. You may download, display, print and reproduce this material provided that the wording is reproduced exactly, the source is acknowledged, and the copyright, update address and disclaimer notice are retained. Disclaimer The authors of this report are members of the Sydney Harbour Research Program at the Sydney Institute of Marine Science and represent various universities, research institutions and government agencies. The views presented in this report do not necessarily reflect the views of The Sydney Institute of Marine Science or the authors other affiliated institutions listed below. This report is a review of other literature written by third parties. Neither the Sydney Institute of Marine Science or the affiliated institutions take responsibility for the accuracy, currency, reliability, and correctness of any information included in this report provided in third party sources. Recommended Citation Hedge L.H., Johnston E.L., Ayoung S.T., Birch G.F., Booth D.J., Creese R.G., Doblin M.A., Figueira W.F., Gribben P.E., Hutchings P.A., Mayer Pinto M, Marzinelli E.M., Pritchard T.R., Roughan M., Steinberg P.D., 2013, Sydney Harbour: A systematic review of the science, Sydney Institute of Marine Science, Sydney, Australia. National Library of Australia Cataloging-in-Publication entry ISBN: 978-0-646-91493-0 Publisher: The Sydney Institute of Marine Science, Sydney, New South Wales, Australia Available on the internet from www.sims.org.au For further information please contact: SIMS, Building 19, Chowder Bay Road, Mosman NSW 2088 Australia T: +61 2 9435 4600 F: +61 2 9969 8664 www.sims.org.au ABN 84117222063 Cover Photo | Mike Banert North Head The light was changing every minute. I climbed over some huge rocks to get into a great position to take some surfing shots, when suddenly this huge cloud covered up the sun. Suddenly the beautiful light illuminating the waves the surfers were riding was gone. I looked to my left and noticed the light here. Quickly, I grabbed my stuff and setup this shot … only got one frame, because soon after this the light here was also gone. Design: Luke Hedge and Marian Kyte 2 | Sydney Harbour 2014 Authors Luke H. Hedge PhD is a Research Fellow at the Sydney Emma L. Johnston PhD is a Professor of Marine Science Institute of Marine Science and Adjunct Associate Lecturer at the University of New South Wales and the Director of the at the University of New South Wales. Sydney Harbour Research Program at the Sydney Institute [email protected] of Marine Science. www.bees.unsw.edu.au/luke-hedge [email protected] www.bees.unsw.edu.au/emma-johnston Shane T. Ahyong PhD is a Senior Research Scientist at the Australian Museum Gavin F. Birch PhD is an Associate Professor of Marine [email protected] Geology at The University of Sydney. http://australianmuseum.net.au/image/Shane-Ahyong [email protected] www.sydney.edu.au/science/people/gavin.birch.php David J. Booth PhD is a Professor of Marine Ecology at the University of Technology, Sydney and the Director of the Bob G. Creese PhD is the Director of Fisheries Research UTS Centre for Environmental Sustainability. at the NSW Department of Primary Industries, as part of NSW [email protected] Trade and Investment. www.professordavidbooth.com/ [email protected] www.dpi.nsw.gov.au/research/staff/bob-creese Martina A. Doblin PhD is an Associate Professor of Marine Science at the University of Technology, Sydney. Will F. Figueira PhD is the Deputy Director of the Centre for [email protected] Research on Ecological Impacts of Coastal Cities at the University http://www.uts.edu.au/staff/martina.doblin of Sydney and the Deputy Director of the Sydney Harbour Research Program at SIMS. Paul E. Gribben PhD is a Senior Research Fellow at the [email protected] University of Technology Sydney and the Deputy Director of http://sydney.edu.au/science/bio/eicc/our_people/directors/ the Sydney Harbour Research Program at SIMS. will_figueira.shtml [email protected] http://cfsites1.uts.edu.au/science/staff/details.cfm?StaffId=4919 Pat A. Hutchings PhD is a Senior Principal Research Scientist at the Australian Museum. Mariana Mayer Pinto PhD is a Research Fellow at the [email protected] University of New South Wales. http://australianmuseum.net.au/staff/pat-hutchings [email protected] www.bees.unsw.edu.au/mariana-mayer-pinto Ezequiel M. Marzinelli PhD is a Research Fellow at the University of New South Wales. Tim R. Pritchard PhD is the Director, Water, Wetlands and [email protected] Coasts Science at the NSW Office of Environment and Heritage. www.bees.unsw.edu.au/ezequiel-marzinelli [email protected] Moninya Roughan PhD is a Senior Lecturer in Oceanography Peter D. Steinberg PhD is a Professor of Marine Science at at the University of New South Wales the University of New South Wales and the Director of the [email protected] Sydney Institute of Marine Science. www.oceanography.unsw.edu.au [email protected] https://research.unsw.edu.au/people/professor-peter-steinberg Acknowledgments The authors are incredibly grateful for the independent reviews of this report conducted by Prof. Frank Talbot AM, Former Director of the Australian Museum, and the United States Smithsonian National Museum of Natural History; and Prof. Peter Fairweather, of The School of Biological Sciences at Flinders University, Adelaide, Australia. A systematic review of the science | 3 © Marian Kyte 4 | Sydney Harbour 2014 Contents 6 Executive Summary 10 Living Harbour. Dynamic Science 10 An Introduction 12 Systematic Literature Review 14 Results 16 The Shape and Form of Sydney Harbour 16 Geological History 16 Hydrology 19 Circulation 20 The Natural Environments of Sydney Harbour 20 Subtidal Rocky Reef 23 Rocky Intertidal Shores 26 Soft Bottoms and Beaches 28 Soft Sediment Macrophytes 30 Open Water / Pelagic Systems 33 Threats to Biodiversity and Ecosystem Function 33 Metalloids, Organo-metallic and Metallic Contamination 37 Nutrients and Turbidity 39 Neo Biota: Non Indigenous and Novel Species in Sydney Harbour 42 Habitat Modification 44 Fishing and Aquaculture 47 Climate Change 50 Stressor Interactions 51 Science and Management 52 Conclusion 55 References 62 Sydney Harbour Database 78 Sydney Harbour Questionnaire A systematic review of the science | 5 Executive Summary The Sydney Harbour estuary is renowned for its biological diversity. Despite the importance of the estuary for the social, economic and environmental health of the city of Sydney, and the nation more generally, there has been no comprehensive compilation or synthesis of the biophysical scientific research conducted within the waterway. This report collates the currently available information within the world’s peer-reviewed, scientific literature. It systematically examines scientific databases and canvasses local, national and international scholars. The result is a comprehensive list of published biophysical information sources. Our report synthesizes this information into a succinct document accessible to stakeholders, policymakers, and the general public. This is produced as a guide to the current state of knowledge of the harbour and readers are directed to the references for further information. Geological History and Geomorphology The Sydney Harbour estuary is a drowned river valley, characterized by steep sided banks carved into Sydney sandstone between 25 and 29 million years ago. Approximately 17 000 years ago, the sea level rose, flooding the river valley and forming a flood tide delta. © Marian Kyte While there are several articles discussing the geology and geological history of the estuary, there has been a greater focus on sedimentology. This Tides in the harbour are semi diurnal and reverse includes examinations of land reclamation in the every six hours. Towards the harbour entrance, estuary, the effects of sediment characteristics on tidal velocities can be as high as 0.25 m.s-1. burrowing crabs, and the effects of coastal cities on Modeled of velocities in the upper branches of the surficial sediments. estuary, however, are only one tenth of those near the entrance. Hydrology and Circulation We have little knowledge of how the EAC and The East Australian Current (EAC) delivers nutrient continental shelf circulation interacts with the Sydney depleted waters just off Sydney’s coast at between Harbour estuary. Previous studies of circulation do 16 oC to 20 oC during the summer months and not take into account the circulation or hydrology 12 oC to 20 oC for the rest of the year. The colder, seaward of the heads. This is important, as up-welled, water during summer may be a potential predicted changes to the EAC due to global source of nutrients into the Sydney Harbour estuary. climate change may have implications for water flows on the continental shelf and tidal exchange Salinity in the harbour is generally the same as in Sydney Harbour. the ocean (35 psu). After rainfall, waters in the Parramatta River can be near fresh for a short time. Subtidal Rocky Reef Salinity at the harbour mouth can be reduced to about 30 psu in the top water layers (upper 4m) after Most studies in this category focus on the habitat- very heavy rain. forming algal species that dominate subtidal reefs in Sydney Harbour. Particular attention has been The most frequent wind patterns are from the given to the effects of artificial structures on natural northeast and are observed 22 % of the time. The reef, and fragmentation of these habitats. Species strongest winds are from the south and are only richness and composition are generally altered by observed 17 % of the time.