In Focus: Research providing knowledge to inform the future management of nutrient levels in the Coorong South Lagoon

Nutrients are known to be a key driver of aquatic ecosystem health. While nutrients are essential for all living organisms, high nutrient levels can lead to problems such as excessive algal growth, or ‘algal blooms’. Ongoing research by the Goyder Institute has identified that this is the case for the Coorong South Lagoon; the knowledge generated through this important research is being used to support decisions for managing nutrient levels and the health of the system.

In our June issue of our eNews, we highlighted that the Goyder Institute-led components of the $77.8 million Healthy Coorong, Healthy Basin (HCHB) program had reached its half-way point. This initiative of the Australian and South Australian governments aims to support the long-term health of the Coorong by providing evidence-based solutions to both immediate threats and future conditions under a changing climate. The Coorong is an area of immense environmental, cultural and social value to South Australia and Australia.

Over the coming months, we will present a series of In Focus snapshots on each of the five research projects being led by the Goyder Institute in collaboration with our partners: the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Department for Environment and Water, Flinders University, the University of Adelaide and the University of South Australia.

This month, we focus on the nutrient dynamics of the Coorong South Lagoon led by Associate Professor Luke Mosley and team at the University of Adelaide and involving other leading researchers from across Australia including the University of South Australia, Flinders University, CSIRO, Griffith University, and Southern Cross University. This rigorous science is providing a knowledge base to be applied to existing and new management interventions to reduce nutrient availability and conditions that promote excessive filamentous algal growth in the Coorong. The data and knowledge generated will improve and validate biogeochemical models that are critical to support evidence-based decisions on flow management and infrastructure options.

The research undertaken by Dr Mosley’s team over the past year has led to some significant insights into the nutrient dynamics of the Coorong system and especially within the Coorong South Lagoon.

Dr Mosley said “Nutrients such as nitrogen and phosphorus have always been a key driver of the ecology of the Coorong. Over the past two decades, we have seen a switch in ecological states of the Coorong South Lagoon from being dominated by aquatic plants such as Ruppia, to being dominated by filamentous algae and phytoplankton. While water levels and salinity levels have played their part in this change, our research over the past year has shown that nutrients are also playing a critical role in the condition of the Coorong South Lagoon.”

Prior to the HCHB Nutrient Dynamics research program, key knowledge gaps existed regarding the influence of flows from the River Murray and from the South East via Salt Creek on importing nutrients into the system, and flushing nutrients out of the South Lagoon.

“What we are finding is that the majority of nutrients are being imported into the Coorong from October to March via the River Murray and Lower Lakes, as well as the Southern Ocean, and then exported from April to September” Dr Mosley said. “This reflects seasonal patterns linked to River Murray inflows (and thus rainfall and climate in the Murray-Darling Basin), and coastal ocean conditions. In comparison, flows from the South East via Salt Creek contribute only a fraction of the nutrients, however, the influence of this localised input is magnified in the South Lagoon.”

It was also previously unknown whether the South Lagoon sediments, particularly in the deeper channels of the lagoon, are acting as nutrient sources or are a repository for nutrients; and what the pathways are for nutrient cycling.

“Our research is showing that the sediment quality and nutrient cycling processes in the South Lagoon are currently in an unhealthy state” said Dr Mosley. “There are approximately 50 times more nutrients in the top 5 cm of sediment compared to the whole water column in the Coorong. This has significant implications for the future management of nutrients to help return the system to an aquatic plant dominated state. Our investigations are showing that improving the flushing of the South Lagoon would help reduce nutrient levels in the water and sediment, and also salinity.”

The current conditions that are impacting the condition and resilience of the aquatic plant Ruppia and even the presence of macroinvertebrate communities in the South Lagoon also has implications for the health of the sediments.

“Anoxic sediments have little or no oxygen in them, and they are present throughout the Coorong South Lagoon. The roots of Ruppia release oxygen into the sediment when they can gather enough light and photosynthesise. This oxygen release supports nutrient cycling and enhances sediment health by reducing the amount of oxygen deprived (anoxic) sediment” said Dr Mosley. “In addition, macroinvertebrates can help introduce oxygen into the sediment when they burrow. Re-establishing more populations of Ruppia and macroinvertebrates in the South Lagoon will assist in reducing sediment and water column nutrient concentrations.”

The next year of research being undertaken by the Goyder Institute team will further investigate the complexities of biogeochemical interactions within and between the sediment and water column, as well as further examining the potential for nutrient removal options to improve the health of the system.

More information on the HCHB nutrient dynamics research can be found here, and the HCHB synthesis report on nutrients in the Coorong can be found here. For further information on the Goyder Institute-led HCHB research, please contact Dr Alec Rolston.

Tags: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Coorong Lower Lakes & Murray Mouth SA Department for Environment and Water (DEW) Flinders University Goyder Institute News Murray River Murray-Darling Basin South Australian Research and Development Institute (SARDI) University of Adelaide University of South Australia Water for the Environment Wetlands

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Chris Wright

Manager Water Science, DEW

Chris Wright holds significant experience in public sector senior leadership, having led policy, scientific and operational business units over the last twelve years in both State and Commonwealth government agencies. Chris has excellent experiences in leading policy and strategy formulation. He is skilled in building and maintaining networks across the public and private sectors to facilitate business delivery; leading and negotiating with others to achieve outcomes; and in bridging the science-policy gap, drawing on earlier roles in geospatial information systems (GIS) consulting. Chris’s formal qualifications include a Bachelor of Social Science, a Masters of Spatial Information Science and graduation from the AICD Company Directors course in 2019.

Dr Ilka Wallis

Senior Lecturer, Flinders University

Dr Ilka Wallis is a hydrogeologist with areas of expertise in quantitative hydrogeology and geochemistry. Ilka focuses on the development of reactive geochemical transport models which integrate fundamental processes that are normally studied in isolation (hydrogeological, mineralogical, geochemical and biochemical).

Ilka is also an Adjunct Professor, Department of Civil Engineering, University of Manitoba, Canada since 2017.

Peter Goonan

Environmental Science Branch, EPA

Peter Goonan is the Principal Aquatic Biologist in the Environmental Science Branch of the EPA. He has over 30 years’ experience monitoring the condition of aquatic ecosystems in SA and assessing the environmental effects caused by discharges, deposits and contaminants entering inland and coastal waters. He specialises in aquatic invertebrate identification and their responses to contaminants and water quality stressors. He also provides expert professional advice relating to water quality risks, regulation, policy, and strategic directions, and represents the EPA as an expert witness in court.

Dr Paul Monis

Manager, Research Stakeholders and Planning, SA Water

Dr Paul Monis is a technical expert within SA Water’s Business Services group, which provides scientific expertise to support the delivery of water and wastewater services to SA Water’s customers. He has specialist expertise in the areas of biotechnology and microbiology, with almost 20 years’ experience applying DNA-based and other technologies to address water quality challenges posed by microorganisms, especially enteric pathogens. Dr Monis also holds title of Adjunct Associate Professor at Flinders University, the University of Adelaide and UniSA.

Jennie Fluin

Principal Advisor Research Partnerships, DEW

Jennie’s role in the Department for Environment and Water (DEW) allows her to foster and strengthen opportunities for researchers to better connect with government to enable evidence-based decision making. Jennie has extensive experience working in both universities and government, allowing her to bridge the divide between the two sectors. She is focused on connecting natural resource researchers with natural resource decision makers, and facilitating fit for purpose partnerships.

Dr Tanya Doody

Principal Research Scientist, CSIRO

Dr Tanya Doody is a Principal Research Scientist working on high impact spatial eco-hydrological projects within CSIRO’s Land and Water Business Unit. Dr Doody leads the Managing Water Ecosystems Group, based in Adelaide, Albury and Canberra and has significant experience in quantifying the water requirements of vegetation and at times, their impact on water resources. This involves ecophysiological field-based research to underpin remote sensing tools to scale regionally to improve our understanding of the effect of flood regimes on the health of water-dependent ecosystems on the Murray-Darling Basin floodplains. Additional research includes investigating the ecological response of vegetation to water availability and environmental water to inform integrated basin water planning and management.

Professor Lin Crase

Dean of Programs (Accounting & Finance), UniSA

Professor Lin Crase is Professor of Economics and Dean of Programs (Accounting & Finance) at UniSA. He joined UniSA in February 2016 as Head of School of Commerce. Prior to commencing at UniSA, Lin was Professor and Director of the Centre for Water Policy and Management at La Trobe University.

Lin’s research has focused on applied economics in the context of water. He has analysed water markets and the property rights that attend them, water pricing and numerous applications of water policy. Whilst his expertise includes the Murray-Darling Basin in Australia, he has also worked on projects in south Asia, Japan and Europe. Lin has published over 100 journal articles, numerous book chapters, four books and a range of other papers and opinion pieces.

Professor Justin Brookes

Director, Water Research Centre, University of Adelaide

Justin has broad research interests in limnology and water treatment with a primary focus on coupling between hydrodynamics, biology and water quality contaminants such as cyanobacteria and pathogens. He is a founding member of the management committee of the IWA Specialist Group on Lake and Reservoir Management and member of the Steering Committee for the Global Lakes Ecological Observatory Network.

Justin has a PhD and a Bachelor of Science degree with Honours from the University of Adelaide.

Daniel Flaherty

Accountant

Daniel Flaherty is the Accountant for the Goyder Institute for Water Research.

Daniel has extensive experience in higher education having worked in senior financial management roles at the University of South Australia, Flinders University and the University of Adelaide over the past 26 years. Daniel has also been a Board Director on a number of university related entities. Prior to that, Daniel has worked in a range of agencies in the Commonwealth and State Governments.

Daniel is a Fellow of CPA Australia and has a Bachelor of Economics from the University of Adelaide.

Dr Alec Rolston

Interim Director

Alec Rolston joined the Institute in 2021 as Research Program Manager of the Goyder Institute’s research projects in the Healthy Coorong, Healthy Basin program. He has extensive experience in integrated water resource management, integrated catchment management, drinking water source protection and wetland ecology, conservation and management across Europe and Australia.

Alec holds a PhD from the National University of Ireland Maynooth and has worked with An Fóram Uisce|The Water Forum and the Dundalk Institute of Technology in Ireland as well as the MANTEL Innovative Training Network across Europe.

Alec spent his early career in Adelaide working with Flinders University through the Coorong, Lower Lakes and Murray Mouth (CLLAMM) Ecology Research Cluster and within the Department for Environment and Water.

Daniel Pierce

Research and Development Officer

Daniel Pierce has managed research projects at the Goyder Institute for Water Research since November 2017 under both the second and third terms of the Institute.

Daniel brings experience in project management and knowledge transfer and application from 4 years working as a Senior Hydrogeologist in the Department for Environment and Water (DEW) in South Australia and from 13 years of private sector work in environmental management, science and engineering in Australia and the South Pacific. His work with DEW has included providing technical advice to the development and revision of Water Allocation Plans around South Australia in collaboration with researchers and policy makers, and managing a team of groundwater modellers and hydrogeologists involved in an assortment of water resource management issues.

Daniel has a Bachelor of Engineering (Hons, Environmental) and a Bachelor of Science (Geography) from the University of Western Australia.

Professor Enzo Lombi

Dean of Research, UniSA STEM

Professor Lombi’s main contributions to environmental research cover various aspects of contaminant risk assessment, biogeochemistry, ecotoxicology and waste management. Furthermore, the methodological development he has pursued in his research has provided the basis for collaborative efforts in a variety of research areas ranging from soil fertility and plant physiology to human health issues related to contaminant uptake via occupational exposure and diet. In the last few years he has been increasingly focusing on the transformation and toxicity of manufactured nanomaterials in the environment.

Dr Carmel Pollino

Research Director Land and Water, CSIRO

Dr Carmel Pollino is a Research Director for Land and Water at CSIRO. She has 20 years of experience working on water issues in Australia and throughout Asia. Carmel has degrees in science and environmental law and works across the science and policy interface. Significant areas of research in Environmental Flows, Hydrology, Ecology and Integrated River Basin Planning. Carmel is the lead and also a contributor to global working groups on water and has published widely in this domain.

Professor Bronwyn Gillanders

Head of School of Biological Sciences, The University of Adelaide

Professor Bronwyn Gillanders is interim Head of School of Biological Sciences at the University of Adelaide. Prof Gillanders completed her BSc at the University of Canterbury, MSc at the University of Otago and her PhD at the University of Sydney. She has a research background in environmental science focused predominantly on freshwater and marine ecology.

Her research interests include integrated marine management; coastal carbon opportunities; multiple use activities and cumulative impact assessment; biology, ecology and fisheries of cephalopods; stocking and provenance of fish; plastics in the marine environment including in seafood; use of fish bones (and other calcified structures) for assessing ecological and environmental change. She has trained and mentored ~70 Honours and Higher Degree Research students and shaped the future of 1000s of students through her undergraduate teaching. She is passionate about encouraging capable women to enter and remain in science careers.

Dan Jordan

Director, Water Security, Policy and Planning, Department for Environment and Water (DEW)

Dan Jordan is the Director, Water Security, Policy and Planning, Department for Environment and Water (DEW). Dan is also the Basin Officials Committee Alternate Member for South Australia.

Professor Okke Batelaan

Dean, School of the Environment, Flinders University

Professor Okke Batelaan is a graduate of the Free University of Amsterdam, Netherlands (MSc – Hydrogeology) and of the Free University Brussels, Belgium (PhD – Engineering). He worked for more than 20 years at the Free University Brussels and also led the hydrogeology group at the KU Leuven, Belgium since 2006. He was chairman of the Interuniversity Programme in Water Resources Engineering.

Since 2012 Okke Batelaan is Strategic Professor in Hydrogeology and currently Dean of the School of the Environment, Flinders University. Okke has broad experience in teaching groundwater hydrology, groundwater modelling, GIS and remote sensing for hydrological applications. He was supervisor of more than 140 MSc and 25 PhD students. He has extensive research experience and a publication record in shallow groundwater hydrology and modeling, recharge-discharge estimation and modeling, urban hydrology and distributed modelling, ecohydrology and impacts of land use and climate change on groundwater systems. He coordinated and participated in a large number of projects in Europe, Africa, South America, Asia and Australia. He is editor-in-chief of Journal of Hydrology: Regional Studies and of MDPI-Hydrology.