Reports

This project investigates the presence and habitat use of the Rakali (Hydromys chrysogaster), an under‑studied semi‑aquatic mammal, across freshwater habitats in Goolwa, South Australia. Using baited camera trap surveys, the study explores how Rakali respond to urbanisation and environmental conditions, contributing the first local population assessment and supporting improved understanding of species responses to human disturbance in freshwater ecosystems.

Historical foredune and beach profile data for the Victor Harbor to Kingston region collected by the Department of Environment and Water, together with LiDAR datasets from 2008 and 2018, were analysed to assess the magnitude of topographic change and to investigate potential shoreline responses to sea level rise. The analysis shows that beach–dune systems in the region exhibit high spatial and temporal variability, with profiles indicating accretion, erosion, or relative stability depending on location. While a small number of sites, such as Victor Harbor and Cape Jaffa, show persistent erosional behaviour and very few (e.g. Goolwa) display accretion, no consistent long-term erosion trend attributable to sea level rise is evident over more than 40 years of observations. Instead, short- to medium-term fluctuations driven by storm-induced erosion and subsequent accretion during calmer wave conditions appear to dominate the record, masking any potential sea level rise signal.

The Coorong, Lower Lakes and Murray Mouth (CLLMM) Research Centre: Communications & Engagement Plan 2023 – 26. DRAFT

The Coorong, Lower Lakes, and Murray Mouth (CLLMM) Research Centre: First Nations Engagement Plan 2023 – 26. DRAFT

Identification of waterbird research priorities for the Coorong, Lower Lakes and Murray Mouth

This Honours thesis examines methane, a highly potent greenhouse gas with significant short‑term warming impacts, investigating the drivers of methane production and fluxes to inform climate change understanding and mitigation.

Freshwater ecosystems are increasingly threatened by urbanisation and human resource use, placing disproportionate pressure on freshwater and semi‑aquatic species. Many semi‑aquatic mammals, including the Rakali (Hydromys chrysogaster), remain under‑studied despite their ecological and cultural importance. This project investigates Rakali presence across an urban‑to‑reserve gradient in freshwater habitats using baited camera trap surveys conducted in 2025. Results show Rakali presence was largely consistent across sites, with detection influenced primarily by lower minimum daily temperatures and baiting periods. This study provides the first population assessment of Rakali in Goolwa, South Australia, and improves understanding of species responses to urbanisation and human disturbance.

The Coorong is a unique lagoon ecosystem in South Australia, where biodiversity is shaped by variations in hydrology and salinity. These environmental factors influence aquatic species composition and, in turn, affect adjacent terrestrial ecosystems. A key species in this system is Ruppia seagrass, which plays an essential role in sediment stabilisation, maintaining water quality, and supporting biodiversity. Climate change and reduced freshwater inflows have disrupted ecological balance in the Coorong, leading to declines in Ruppia abundance and distribution. This project investigates the eukaryotic communities associated with Ruppia to better understand plant–environment interactions and how these communities respond to changing conditions, using statistical analysis of environmental data to identify key drivers of ecological variation.

Pasteurella multocida is the aetiological agent of Fowl Cholera which affects a wide variety of domestic and wildlife avian species worldwide. This paper aims to document the Fowl Cholera outbreak which was first detected among waterfowl in the Coorong RAMSAR wetland, South Australia in January 2024.

Movement Ecology of Chestnut Teal in the Coorong, Lower Lakes, and Murray Mouth, South Australia

Freshwater mussels are integral to freshwater biodiversity and provide critical ecosystem services. As filter feeders, they are ideal indicators of water quality and ecosystems health. Globally, human modification of aquatic ecosystems threatens freshwater mussel populations. The Coorong, Lower Lakes and Murray Mouth (CLLMM) region is home to the floodplain mussel (Velesunio ambiguus). Freshwater mussels are of cultural importance to First Nations in Australia, including Ngarrindjeri people of the CLLMM region who know freshwater mussel as Lokeri (Loker-engk for two mussels; Lokerar for three or more mussels). Forgotten caches of Lokeri dated to over 8000 years old have been found on Ngarrindjeri Country thereby demonstrating its use as a food source. A greater understanding of Lokeri on Ngarrindjeri Country will provide essential knowledge to address cultural considerations and the ecological management of the species. The citizen science ‘muscles in the mud’ project was sparked by community interest in the contemporary status of Lokeri in the Lower Lakes, where it was very abundant up until the early 2000s but disappeared by 2009 during the Millennium Drought. The first aim of the project was to connect with community to discuss project objectives, identify potential survey sites and increase awareness of Lokeri. The second aim was to conduct a widespread survey of Lake Alexandrina and Lake Albert to identify if and where Lokeri may be present. The third aim of the project was to examine shells of Lokeri collected from the Lower Lakes to compare three approaches to determining age and growth (counting growth increments from the umbo section and from the full cross-section, and counting external growth interruption lines). In November 2024, more than 50 members of the Ngarrindjeri community attended two yarning circles held in Raukkan and at Point Sturt. The lead researcher presented the idea for a Lokeri project that included a survey where community members could be employed to participate in field and laboratory work. The events provided a successful way to inform community of the intention to conduct a survey on Ngarrindjeri Country and the opportunity for people to participate. After the yarns, Community members entered the water, searched for Lokerar and shared knowledge across generations. This work supported both the collection of information and the continuation of cultural practice. Many not having been in the water for years and feeling connected to the water again after being disconnected for so long. Many reporting how their mi:wi (spirit) felt happy again. In December 2024, 34 sites were surveyed in the Lower Lakes in lake-edge habitats known to be preferred by Lokeri. Lokeri presence and abundance at each site was measured using three adjacent 10 ×10 m quadrats in a randomly chosen location that were accompanied by a wider general search up to 50 m from shore and approximately 50 m either side of the quadrats. Numbers of live Lokeri and empty shells were recorded and each live Lokeri was measured for a range of morphometric parameters including length, height and width. A total of 76 live floodplain mussels and two river mussels (Alathyria jacksoni) were recorded from 9 and 1 of the 30 sites in Lake Alexandrina, respectively, but neither species was detected in Lake Albert. The quantitative surveying revealed low abundances across all sites, with temporal comparison from surveys conducted 45 years prior at Point Sturt, Lake Alexandrina, indicating the current population is

The Coorong is a Ramsar‑listed wetland of international importance, where diverse phytoplankton communities play a critical role in maintaining ecological balance and water quality. Climate change, reduced freshwater inflows, rising salinity, and extreme weather events are driving changes in phytoplankton abundance and composition, with implications for aquatic food webs and ecosystem health. This project uses machine‑learning approaches, including Random Forest models, to analyse environmental data and assess how climate stressors influence phytoplankton communities, supporting adaptive management and long‑term resilience of the Coorong wetlands.

Wetlands play a vital role in regulating the hydrological cycle, supporting flood control, and filtering pollutants. Scientists and First Nations Peoples have long recognised the ecological, cultural, and economic value of these ecosystems. However, it was not until the mid to late twentieth century that this understanding was formally reflected at an international level. In response to accelerating wetland loss and degradation, the Convention on Wetlands of International Importance, especially as Waterfowl Habitat—commonly known as the Ramsar Convention—was adopted in Ramsar, Iran, in 1971. The Convention entered into force in 1975, with Australia among its earliest signatories. Through the establishment of the Convention, signatory states formally acknowledged the close interdependence between humans and the environment, and the fundamental ecological functions of wetlands as regulators of water regimes and as habitats supporting diverse flora and fauna. The Ramsar Convention reflects a shared recognition that wetlands are resources of immense economic, cultural, scientific, and recreational value, and that their loss would be irreversible. As such, their protection was—and remains—imperative, particularly in the face of growing pressures such as climate change.

Honours thesis submitted in partial fulfilment of the requirements for the degree of Bachelor of Science (Honours), Discipline of Ecology and Evolutionary Biology, School of Biological Sciences. The University of Adelaide.