Scientific Trials and Investigations
The Healthy Coorong, Healthy Basin Scientific Trials and Investigations (T&I) project was an integration project, designed to unite past and new knowledge gained from the investigations, and then translate it into tools and products to inform and optimise management of the Coorong.
T&I brought together independent experts in multi-disciplinary collaborative teams across the Goyder Institute for Water Research, including staff 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.
The Healthy Coorong, Healthy Basin (HCHB) program recognises that a collaboration between science, Traditional Owners and the community is critical to the continued restoration of this breathtaking landscape. As such, the scientific trials and investigations project is working to fill critical knowledge gaps and provide the scientific evidence-base to inform management actions to improve the long-term health of the Coorong.
More specifically, trials and investigations will inform the development of improved ways to:
- reduce nutrient loads (levels) and algae abundance in the Coorong
- switch the South Lagoon back to an aquatic plant dominated system rather than an algal dominated system
- provide the food resources that are required to support waterbirds and fish populations
- increase the abundance and distribution of waterbird populations at local and regional scales within the Coorong
- incorporate cultural knowledge and values of the First Nations into decision-making
- identify the adaptation pathways that are required to ensure that the ecological values of the Coorong are maintained into the future under a changing climate.
An integration project will unite past and new knowledge gained from the above trials and investigations and translate it into tools and products to inform and optimise management of the Coorong. Results of the trials and investigations, along with community and Traditional knowledge, will provide new information to help make better evidence-based decisions about future long-term management actions such those being delivered through the Coorong Infrastructure Investigations and On Ground Works projects.
Bringing together industry-experts
Trials and investigations brings together independent experts in multi-disciplinary collaborative teams across the Goyder Institute for Water Research, including staff 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).
A First Nations knowledge project is being led by the Ngarrindjeri Aboriginal Corporation. Find out more.
Healthy Coorong, Healthy Basin - Phase One project summary
Publications
For a full list of trials and investigations reports please visit the publications page.
Key findings report
Technical reports
Discussion paper
Video
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.
What we are doing
Knowledge of nutrient cycling processes in the Coorong South Lagoon is critical to the development of short and long-term management actions that will improve water quality and support habitat requirements for plants, waterbirds and fish.
Research is currently being undertaken to improve knowledge of the drivers and sources of undesirable nutrients, which are causing poor water and sediment quality in the Coorong. This involves undertaking sampling to assess the nutrients in the water and the interaction with other drivers of poor water quality to determine how to manage nutrient levels to improve water quality.
Studies are underway to consider nutrient removal options at a system scale. Key findings and strategies are being considered and will provide the basis for potential future management activities.
What we have done so far
Key developments and findings from investigations include:
- The Trials and Investigations team has been surveying sediment and water quality as well as collating and reviewing existing data.
- The Coorong South Lagoon is hypersaline (high salinity) and hypereutrophic (high in nutrients) and reduced flushing has resulted in prolonged periods of this state.
- Poor sediment quality (sulphide rich sediments) is widespread with few benthic (living on the bottom) organisms present. These factors are negatively impacting on benthic flora and fauna communities
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.
What we are doing
Research is currently being undertaken to understand the reasons behind the spread of filamentous green algae in the Coorong and how we can move the Coorong from an algal dominated environment back to an aquatic plant dominated environment. Research will investigate how filamentous green algae and aquatic plants respond to temperature, water quality changes and different sediment types. Scientists have investigated innovative methods to map the extent of aquatic plants and algal blooms, and to control algae and prevent it from interfering with seed production in native aquatic plants.
What we have done so far
Key developments and findings from investigations so far include:
- Development of a new method to detect and map floating algae in the Coorong via satellite imagery, which will be used to monitor changes over time and help us understand the conditions under which algal blooms occur.
- Evidence that filamentous algae is now attaching to aquatic plants throughout much of the Coorong, reducing seed production and germination of new plants.
- Evidence from laboratory experiments that algal growth can be controlled under specific temperature, salinity and nutrient conditions.
- Small-scale trials to remove filamentous algae in the Coorong have been undertaken to assess short-term approaches to reduce the impact of algal blooms.
- Updated models are being developed to improve our ability to predict the impacts of water quality and flow conditions on aquatic plants.
This information will be used to develop a strategy to restore native aquatic plant communities in the Coorong in order to provide key habitat and food for fish and birds. It will also be used in modelling to inform the short and long-term management options currently being investigated to improve the health of the Coorong.
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 foodweb 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.
What we are doing
Research is currently being undertaken to better understand the primary food sources for key fish and waterbird species in the Coorong, the availability and nutritional value of food, and the habitat requirements of those food sources, which include macroinvertebrates, plankton and fish. Scientists have been sampling these along the Coorong to determine the quantity and quality of potential food items.
What we have done so far?
Key developments and findings from investigations so far include:
- Evidence for strong regional variations in the availability of potential food resources to support waterbird and fish populations.
- A confirmed decline in the number of species of macroinvertebrate and fish species from north to south in the Coorong in relation to rising salinity.
- The total abundance of small-bodied fish was well below the long-term average.
- The energy content of potential food items for birds and fish is higher at the Murray Mouth and in the North Lagoon than in the South Lagoon.
The research will be used in modelling to inform the short and long-term management options currently being investigated to improve the health of the Coorong.
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.
What we are doing
Scientists have been investigating options to increase the availability and quality of wetlands to provide greater food resources to support waterbird populations.
An expert multi-disciplinary team of leading ecologists has been established to address this complex issue, including leading Australian ornithologists, limnologists, modellers and statisticians.
The research team will combine new information regarding food resources (from the foodwebs investigations) with measures of habitat quality to develop ‘waterbird response models’.
These models will be used to forecast how waterbirds will respond to changes in habitat conditions and management interventions. The models will be supported by field data collected through a collaboration with BirdLife Australia.
This information will provide targeted evidence to inform short and long-term management interventions currently being investigated for the Coorong and surrounding wetlands to support habitat for waterbirds.
What we have done so far
Key developments and findings from investigations include:
- Management of the constructed Tolderol wetlands provides abundant food resources for the shallow wading habitats that constitute quality feeding habitat for waterbirds, including migratory shorebirds.
- The identification of wetlands in the Lower Lakes and Upper South-East that could be managed in coordination with the Coorong, to provide further habitat for waterbirds and improve waterbird populations within the Coorong.
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.
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.
Research is currently being undertaken to understand how the Coorong can be managed to maintain its ecological character in the face of climate change.
The research involves looking at climate change trajectories to identify which values are most at risk and identifying the management actions and policy decisions that are needed, both now and in the future, to maintain these values. This involves scoping different expectations about how a ‘Healthy Coorong’ might be defined in the face of sustained climate and ecological change.
This work will result in the development of a Climate Adaptation Plan that will describe actions to underpin policy and management of the Coorong that is effective in the face of future change.
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
