Scientific Trials and Investigations
The Healthy Coorong, Healthy Basin Scientific Trials and Investigations (T&I) project ran from July 2020 – June 2022 and was designed to identify and address remaining scientific knowledge gaps to inform the development of targeted and effective management actions for the Coorong.
About the project
Through two decades of monitoring and research conducted under The Living Murray Program (since 2002) and Coorong, Lower Lakes and Murray Mouth Recovery project (2011-2016), we have built a good understanding of the Coorong and its role in supporting a unique diversity of fish, plants and waterbirds.
However, some elements of the Coorong ecosystem have now undergone a number of long-term changes and a number of new threats to the ecosystem present new management challenges for which we need to find solutions.
Through the T&I project, $10.9M was invested in new science in the fields of nutrient dynamics, aquatic plants and algae, food webs, waterbirds, climate adaptation, and science integration. The project's priorities and goals were developed in partnership with the Goyder Institute for Water Research, including scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the Department for Environment and Water, Flinders University, The University of Adelaide, University of South Australia and the South Australian Research and Development Institute (SARDI). The First Nations knowledge project was led by the Ngarrindjeri Aboriginal Corporation.
This unprecedented investment generated critical knowledge and capability for the management of the Coorong through a collaborative, transdisciplinary team from 13 organisations, including more than 70 researchers and 20 government scientists, with a strong focus on early career researchers to build capacity in South Australia.
Key Publications
For a full list of trials and investigations reports and fact sheets please visit the publications page.
Video: Introduction to Scientific Trials and Investigations
Key findings report
Science delivered across seven project components addressed critical knowledge gaps and tested assumptions to determine how to transform the Coorong from its current vulnerable state to a healthier and more resilient ecosystem.
State of the Coorong discussion paper
The discussion paper seeks to build a shared high-level understanding of the existing and emerging knowledge of the Coorong to guide current and future restoration and adaptive management, with a focus on the southern Coorong.
State of the Coorong discussion paper - Healthy Coorong, Healthy Basin Sep 2024
Areas of investigation included in T&I
The problem
The Southern Coorong is currently in a high nutrient state due to reduced flushing of salt and nutrients from the system, which has impacted on the quality of water and sediment habitats for macroinvertebrates, plants, fish and waterbirds.
Priority research questions
- What are the sources and amounts of nutrients coming into the Coorong and where do they reside?
- What forms of nutrients are present and how are these influencing ecological processes and function?
- What are the pathways for restoring healthy nutrient cycling and nutrient export?
Nutrient dynamics key findings
Publications
Technical reports
- Coorong water quality synthesis with a focus on the drivers of eutrophication
- Sources and transport of nutrients in the Coorong
- Coorong nutrient cycling and fluxes
- A scientific evaluation to inform nutrient removal options for the Coorong
Technical notes
Fact sheets
- Nutrient cycling in the Southern Coorong
- The role of sediments in the eutrophication of the Southern Coorong
- Monosulfidic black oozes are anoxic and alter nutrient cycles
- Pathways to reversing the hypereutrophic nutrient state of the Coorong
Video
The problem
Aquatic plants are a key component of the Coorong ecosystem, providing habitat for fish, food for waterbirds, and improving water quality. Since the Millennium Drought, the health and extent of aquatic plant communities have decreased in the Coorong, mainly due to inadequate water flows, water levels, poor water and sediment quality, and the resulting impacts of blooms of algae and other microbiota.
Priority research questions - aquatic plants
- What is the current composition and extent of the aquatic plant community in the southern Coorong?
- What are the effects of salinity, temperature and nutrients on aquatic plant growth that inform our ability to optimise habitat that favours longer lived, higher biomass aquatic plants over algae?
- What are the critical elements required to provide long term, large scale, successful restoration of Ruppia communities in the southern Coorong?
Aquatic plants key findings
Priority research questions - algae
- What are the thresholds of survival for the southern Coorong filamentous algal community?
- Does reducing the algae levels improve Ruppia Community abundance and distribution in the Coorong?
- How can we manage algae to support recovery of aquatic plants?
- Can conditions in the Coorong be managed to return to an aquatic plant dominated system rather than algal dominated, without intervention?
Algae key findings
Publications
Technical reports
- The growth of aquatic macrophytes (Ruppia tuberosa spp. and Althenia cylindrocarpa) and the filamentous algal community in the southern Coorong
- Experimental testing of Coorong filamentous algal growth with increasing temperature and salinity
- Investigation of the application of remote sensing to estimate coverage of surface exposed (floating) filamentous algae in the Coorong, South Australia
- Distribution and seasonality of the Ruppia dominated aquatic macrophyte community and filamentous algae in the southern Coorong
- A restoration strategy for the Ruppia Community of the southern Coorong
- Microbial community composition of the southern Coorong including evaluating seasonal variation and sediment, water column, aquatic macrophytes and filamentous algae as substrates for microbial growth
Fact sheets
- The aquatic plants of the Southern Coorong
- Why aquatic plants are important
- Aquatic plant lifecycles in the Southern Coorong
- Algae affects recovery of aquatic plants
Video
The problem
Healthy fish and waterbird populations in the Coorong need to be supported by a healthy food web in which food items exist in sufficient quantities and qualities (that is, high energy) and are accessible. Changes in water levels and water quality in the Coorong over time have altered the composition and availability of food resources for important species such as fish and waterbirds.
Priority research questions
- What are the primary food sources for key fish and waterbird species in the Coorong South Lagoon and their relative importance?
- How does the availability of zooplankton, macroinvertebrate and fish food vary with key environmental drivers?
- How energy rich and nutritious are the major food items for key fish and waterbird species?
- Can we quantify food web links and develop an integrated food web model for the Coorong ecosystem?
Coorong food webs key findings
Publications
Technical reports
- A synthesis of current knowledge of the food web and food resources for waterbird and fish populations in the Coorong
- The current state of food resources supporting waterbird and fish populations in the Coorong
- Primary food resources for key waterbirds and benthic fish in the Coorong
- Food resource availability, energy content and nutritional value of major food sources for key fish and waterbird species under varying environmental conditions in the Coorong
- Ecosystem models to inform the development of strategies to restore a functioning South Lagoon food web in the Coorong
Video
The problem
The Coorong is a critical wetland for waterbirds and has regularly provided important breeding, feeding and refuge habitats for more than 100,000 birds each summer. Some waterbird populations are currently experiencing declines at an international or national level, however there is growing evidence that many species are declining at faster rates in the Coorong in response to poor habitat condition and low food availability.
Priority research questions
- How do key waterbirds species use the Coorong and regional wetlands?
- How do we effectively measure habitat quality for key waterbird species?
- What are the critical habitat features that support key waterbird species in the Coorong and regional wetlands?
Waterbirds key findings
Publications
Technical reports
- Review of the ecology, status and modelling of waterbird populations of the Coorong South Lagoon
- Assessment of Tolderol Game Reserve in autumn 2019 to support key species of Coorong waterbirds
- An initial assessment of the potential for wetlands in the South East and Lower Lakes regions of South Australia to support key species of Coorong waterbirds
- Response models for key waterbird species of the Coorong
- Recommended habitat quality measures for key waterbird species in the Coorong
- Response models for waterbird species of the south-east of South Australia
- Spatial and temporal habitat use by key waterbird species in the Coorong
Fact sheet
Video
The Kurangk (Coorong) is of enormous cultural significance to the Ngarrindjeri people. The Ngarrindjeri people have a deep understanding of the ecological functioning of the Coorong and their knowledge of the environment has been passed down through generations.
The Ngarrindjeri knowledge project, led by the Ngarrindjeri Aboriginal Corporation, will document an understanding of the methods, knowledge and cultural values of the Ngarrindjeri people and consider this knowledge for management of the Coorong, now and in the future.
The project will establish a culturally appropriate knowledge database, owned by the Ngarrindjeri people that can be used to inform the management of the Coorong. The research will focus on Ngarrindjeri knowledge of fresh water soaks and wells along the Coorong, No:ri (pelican) breeding islands and the importance of the South Lagoon/Salt Creek to the breeding cycles of Ngarrindjeri Ngartjis (totems) – in particular, species such as the jumping mullet.
Ngarrindjeri Yarluwar Ruwe methodology (a research/assessment methodology based on traditional principles) will also be refined through the project.
Ngarrindjeri knowledge project
The problem
The Coorong is vulnerable to climate change due to the potential impacts of reduced inflow, sea level rise and increased temperatures, which are known to be important drivers of the system. Adapting the management of the Coorong will be complex as the climate continues to change; requiring dynamic adaptation on ecological, social and institutional levels, over many decades
Priority research questions
- Which of the multiple values held by people for the CLLMM could persist as the system transforms in response to climate change?
- What future changes in management might be required to maintain values in the long term?
- What institutional changes could help guide adaptation decision-making?
- What near-term actions could help communities understand on-going change, maintain valued connections to the system as it changes, and enable new options for future policy and management?
Climate adaptation key findings
Publications
Technical reports
- Trajectories of ecological change in the Coorong and Lower Lakes, in response to climate change
- Preliminary climate change vulnerability assessment for the Coorong, Lower Lakes and Murray Mouth
- Preliminary adaptation pathways for the Coorong, Lower Lakes and Murray Mouth
Video
Science Integration is a process that brings together, develops and applies the knowledge and tools that have been generated across the Trials and Investigations project.
Science integration activities
- Development and improvement of hydrodynamic, biogeochemical and ecological response models
- Validation of models against observed data and application of models through development of detailed scenarios to assess management options for the Coorong
- Development of methodologies and frameworks to summarise, evaluate and communicate potential outcomes of scenarios for management options
- Interpreted and synthesised, up-to-date science that guided feasibility assessments and provided the evidence base for decision-making and prioritised Program directions
Science integration summary
Next steps
The science is clear that the southern Coorong has suffered long-term decline and is currently in a degraded state. Read more about the next steps towards a healthier Coorong, as outlined in the Coorong Restoration Roadmap.
