Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program

Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program Published by: Land & Water Australia Postal address: GPO Box 2182, Canberra ACT 2601 Office location: Level 1, The Phoenix, 86 Northbourne Avenue, Braddon ACT Telephone: 02 6263 6000 Facsimile: 02 6263 6099 Email: Land&[email protected] Internet: www.lwa.gov.au © Land & Water Australia Copyright: Copyright of this publication, and all of the information it contains, vests in the Land and Water Resources Research and Development Corporation, with its brand name being Land & Water Australia. The Corporation grants permission for the general use of any or all of this information provided due acknowledgement is given to its source, apart from the two exceptions noted below. Photos of the Gippsland Lakes (page 3) and Leadbeater’s possum (page 132) are used under restricted licence. Permission to use these images should be directed to the copyright holders listed in caption. Disclaimer: The information contained in this publication is intended for general use, to assist public knowledge and discussion, and to help improve the sustainable management of land, water and vegetation. It includes general statements based on scientific research. Readers are advised and need to be aware that this information may be incomplete or unsuitable for use in specific situations. Before taking any action or decision based on the information in this publication, readers should seek expert professional, scientific and technical advice. To the extent permitted by law, the Commonwealth of Australia, Land & Water Australia (including its employees and consultants), the authors and its partners do not assume liability of any kind whatsoever resulting from any person’s use or reliance upon the contents of this document. Citation: Lovett, S., Price, P. & Edgar, B. (eds) 2007; Salt, Nutrient, Sediment and Interactions: Findings from the National River Contaminants Program, Land & Water Australia, 2007. Editorial assistance: A. Mortlock Print ISBN: 978-1-921253-68-3 Electronic ISBN: 978-1-921253-63-8 Product code: PK071328 Cover photos: Left to right, then top to bottom. Front cover: Lien Sim, Phillip Ford, courtesy Chapter 9, Lien Sim, Paul Boon, courtesy Chapter 9, Lien Sim, Phillip Ford, courtesy Chapter 8, Colin Clay, Phillip Ford, Gunther Schmida, Jenny Davis, Roger Charlton, Phillip Ford. Back cover: Bill Johnson, Lien Sim, courtesy Chapter 8, Jason Dunlop, Ben Kefford, courtesy FRDC, Ben Kefford, Lien Sim, Darryl Holland, Ben Kefford, Mike Wagg, courtesy Chapter 9, Ben Kefford, courtesy Chapter 11, Lien Sim. Inside cover: Lien Sim Design: Angel Ink Print: Paragon Printers Date: August 2007 The National River Contaminants Program is a joint collaboration between Land & Water Australia and the Murray-Darling Basin Commission. Anabaena circinalis. Photo CSIRO. Contents 1 The National River Contaminants Program 1 Brendan Edgar, Richard Davis and Phil Price Salt introduction 7 2 Understanding salinity thresholds in freshwater biodiversity: freshwater to saline transition 9 Ben Kefford, Jason Dunlop, Dayanthi Nugegoda and Satish Choy 3 Understanding thresholds in the transition from saline to hypersaline aquatic ecosystems: 29 south-west Western Australia Lien Sim, Jenny Davis, Jane Chambers and Karin Strehlow Nutrient introduction 41 4 Managing diffuse nitrogen loads: in-stream and riparian zone nitrate removal 43 Christine Fellows, Heather Hunter and Michael Grace 5 Managing algal blooms in Australia 59 Brendan Edgar and Richard Davis 6 Making better fertiliser decisions: grazed pastures 71 Cameron Gourley, Alice Melland, Raquel Waller, Ivor Awty, Andrew Smith, Ken Peverill and Murray Hannah Sediment introduction 83 7 Identifying sources of sediment in river basins to help develop revegetation priorities 85 Scott Wilkinson and Cris Kennedy 8 Budgeting and monitoring for sediment and nutrients at the catchment scale 93 Myriam Bormans, Phillip Ford, Arthur Read, Heather Hunter, Rob Dehayr and Christine Fellows Interactions introduction 107 9 Managing regulated flows and contaminant cycles in floodplain rivers 109 Darren Ryder and Sue Vink 10 Risk-based approaches for managing contaminants in catchments 127 Barry Hart, Carmel Pollino, Andrea White, Michael Grace, Mark Burgman, David Fox, Jan Carey, Yung En Chee, Brent Henderson and Elisabeth Bui 11 The role of modelling in catchment management 141 Lachlan Newman, Susan Cuddy, Christopher Rutherford and Anthony Jakeman SALT, NUTRIENT, SEDIMENT AND INTERACTIONS 1 Chapter 1 — The National River Contaminants Program Brendan Edgar, Richard Davis and Phil Price Land & Water Australia Summary The National Rivers Contaminants Program (NRCP) has had a range of important highlights including: • new knowledge on how salinity affects animals in rivers, and guidance for managers on setting targets and environmental flows, • improved management by the fertiliser industry in advice it provides to the dairy, sheep and beef producers, and • new knowledge for managers on the role of riparian zones in influencing the passage and transformation of nitrogen into streams. 2 FINDINGS FROM THE NATIONAL RIVER CONTAMINANTS PROGRAM Macquarie Marshes, NSW. Photo Bill Johnson. Gorgonian seafans off Whitsunday Island. Photo FRDC. Background To improve our understanding and management of river contamination issues and, ultimately, to help reduce The Australian community is increasingly aware of the associated environmental, social and economic costs, the importance of our water resources and riverine the National River Contaminants Program (NRCP) was environments to the future sustainability of agriculture, established in 2001 by Land & Water Australia (LWA) rural and urban water supply, estuaries and in-shore and the Murray-Darling Basin Commission (MDBC). fisheries, recreation, and conservation of our unique This continued the partnership between LWA and the aquatic biodiversity. Consequently, river restoration has MDBC from the preceding National Eutrophication become a priority for many catchment and resource Management Program, that focused on the causes and managers looking to repair damaged rivers. Contaminants management of algal blooms in waterways, including in rivers are central to this issue because they determine the role of phosphorus as a contaminant. both the quality of irrigation and drinking water, as well The National River Contaminants Program Strategic as the condition of in-stream habitats for river-dependent Plan (ATECH 2000) canvassed the views of catchment plants and animals. and river managers about the most important river River contaminants fall into two broad categories — contaminant issues. Using this data, outlined in Figure 1, firstly, substances that occur naturally, but for which it was agreed to focus the Program on developing significant increases in the amounts present contaminate strategies for better managing salt, nutrients and the environment, and secondly, those that do not occur sediments as priority contaminant issues. naturally, for which even small amounts may contaminate the environment. Examples of the first category are salt, Other nutrients, and sediments — about which we need to Temperature understand the sources of excess loads, their ecological Acidification Salinity effects, and options for improved management. Examples Pesticides of the second category are agricultural chemicals and Heavy metal heavy metals, about which we need to understand their Organic matter ecological effects and the extent to which we need to improve their management. Sediment River contaminants are also a major threat to receiving waters (estuarine, coastal, wetland and Nutrient reservoir). Some of these ecosystems are of enormous national value, e.g. the Great Barrier Reef, Gippsland Figure 1. Indicative national significance of river contaminant Lakes, Macquarie Marshes, and Swan-Canning estuary. issues (regional significance may be different). SALT, NUTRIENT, SEDIMENT AND INTERACTIONS 3 Ninety-mile Beach and Gippsland Lakes, Vic. Photo © Reg Morrison / The Channels, WA. Photo Jenny Davies. AUSCAPE. The first activity of the NRCP was a workshop (June Areas of Program research 2001) to scope the sources, pathways and transformations of each of these contaminants within river systems, Salt as a contaminant and to consider the possible interactions between them. Salinisation of landscapes and rivers has been identified A Program Plan was prepared to guide investments, as one of Australia’s most serious environmental issues, knowledge management and evaluation over the life of particularly for southern regions (MDBC 1999), but the Program (NRCP R&D Plan 2001, LWA). is also a high risk for some warm temperate and dry The objective of the NRCP is to improve our tropics regions (Council of Australian Governments understanding and management of river contamination 2000). In areas already affected, secondary (or dryland) issues, to help reduce the associated costs and to better salinity has severely impacted on ecosystems with large manage the risk of river contamination. To do this we losses of habitat, biodiversity, native vegetation and water need to understand: resource value. • where contaminants are coming from in the Much is now known about the causes of dryland landscape, salinity, and a number of effective strategies

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