This record provides an overview of the NESP Marine and Coastal Hub project "Mapping critical Australian sea lion habitat to assess ecological value and risks to population recovery". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Australian sea lion populations have declined by more than 60% over the past four decades. Abundance and trends vary markedly across the species range, suggesting that localised risk profiles from threats - such as bycatch, marine pollution, and habitat degradation - vary at small spatial scales. Fine scale variation in habitat use is thought to underpin these differences, yet knowledge about Australian sea lion's dependency on key habitats and their vulnerability to human impacts is limited. This project deployed compact animal-borne cameras with GPS and motion sensors on eight adult female sea lions at two key colonies: Seal Bay (Southern Kangaroo Island Marine Park) and Olive Island (Western Eyre Marine Park). The devices recorded nearly 80 hours of footage over 560 km of seabed, identifying six distinct benthic habitat types, including previously unmapped rocky reefs and kelp forests. The footage was used to develop fine-scale habitat maps using machine learning models, providing a valuable baseline for assessing ecological value, foraging intensity, and the effectiveness of protected areas. This innovative approach complements traditional seafloor mapping and offers a scalable, cost-effective method for locating and monitoring critical habitats for endangered marine species. The results directly inform recovery planning, fisheries management, marine park design, and the identification of Biologically Important Areas. Ongoing camera deployments at Seal Bay and new sites along the western Eyre Peninsula will improve understanding of sea lion colony-specific behaviours and contribute to long-term monitoring of habitat change, diet, and emerging threats. Outputs • Tracking data from sea lion-deployed tags: location, depth, time, temperature, light, acceleration [dataset] • Timestamped video footage from sea lion-deployed cameras [dataset] • Final project report [written]

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Enhancing monitoring approaches to evaluate the abundance, life history and critical habitats of the endangered Australian sea lion". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The Australian sea lion (Neophoca cinerea) is Australia’s only endemic pinniped and is listed as Endangered under the EPBC Act. Populations have declined by more than 60% over the past 40 years and are vulnerable to threats including fisheries bycatch, disease, pollution, marine debris entanglement and climate change. Improving knowledge of abundance, demography and critical habitat use is essential for evaluating threats and guiding recovery actions, but is difficult due to the species’ breeding biology, longevity, seafloor foraging behaviour and use of remote breeding sites. This project developed and applied cost-effective methods to improve monitoring of Australian sea lion populations, particularly in under-surveyed regions exposed to anthropogenic pressures. It included four linked components: (1) helicopter and remote-camera surveys of breeding sites in the Recherche Archipelago; (2) drone surveys of selected breeding and haul-out sites in Western Australia and South Australia; (3) processing and analysis of long-term demographic data from the microchipped Seal Bay population; and (4) continued deployment of underwater cameras to identify habitat use, foraging behaviour and potential risks. The project was co-designed with Indigenous partners, including Yalata Anangu Aboriginal Corporation, Far West Coast Aboriginal Corporation and Esperance Tjaltjraak Native Title Aboriginal Corporation. Indigenous partners contributed to delivery of project components, including drone-based monitoring and field activities, supporting Indigenous leadership in the use of new technologies for sea lion monitoring and Healthy Country management. Outputs included updated abundance and breeding-site information, validated drone survey methods, improved workflows for demographic analysis, and additional animal-borne camera data on critical habitats. These data and methods support implementation of the Australian Sea Lion Recovery Plan, long-term state government monitoring, assessment of cumulative impacts and recovery actions, and conservation planning linked to Sea Country values. Outputs • Qualitative and qualitative spatial assessments of breeding sites from helicopter surveys in Recherche Archipelago [dataset] • Drone-collected photogrammetry, FLIR, thermal imaging and LiDAR data [dataset] • Demographic results from analysis of Seal Bay microchipping program [dataset] • Tracking data from sea lion-deployed tags: location, depth, time, temperature, light, acceleration [dataset] • Timestamped video footage from sea lion-deployed cameras [dataset] • Short non-technical summaries to distil the key findings and take-home messages [written] • Final project report [written]