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.

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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]