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 (ASL; Neophoca cinerea) is Australia’s only endemic pinniped. Populations have declined by more than 60% over the last 40 years to extremely low levels, leading to its endangered status. Known threats to the species include fisheries bycatch, disease, pollution, entanglement in marine debris, and climate change. Improving our understanding of the species’ abundance, life history and critical habitats is essential for evaluating these threats and guiding recovery actions but is challenging due to the species’ unique life-history and breeding biology, longevity, demersal foraging behaviour and occupancy of remote breeding habitat. This project aims to improve the monitoring and inform the management of Australian sea lions by developing cost-effective methods for acquiring abundance data from under-surveyed regions impacted by anthropogenic pressures. To do so, it will: • Apply drones to enhance monitoring at suitable breeding and haul-out sites • Develop efficient techniques to process and analyse demographic data so that survival and reproductive success estimates from a microchipped population at Seal Bay can be routinely updated; and • Continue to deploy underwater cameras on sea lions to identify and understand critical habitats and risks. Findings from these activities will underpin the National Recovery Team conservation efforts, in line with the Australian Government's Threatened Species Action Plan and Healthy Country plans. 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]