This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2023 project "Eastern Grey Nurse Shark population abundance and trend". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Grey nurse sharks are a nationally significant threatened species, with Australia’s eastern population listed as Critically Endangered under the EPBC Act. The Recovery Plan for the Grey Nurse Shark identifies the need for robust estimates of abundance, population trend, age structure, survival and range, particularly where conservation measures such as spatial closures and protection of aggregation sites are in place. This project refined abundance and trend estimates for the eastern Australian grey nurse shark population by combining biopsy sampling, genetic analysis, stereo-video length measurement and statistical modelling. Tissue samples from more than 300 sharks were analysed using close-kin mark-recapture methods to identify family relationships and estimate adult population size. Stereo-video measurements supported improved age estimation using Australian-specific length-at-age models, reducing reliance on overseas growth data. Findings from the project provide a stronger evidence base for Australian and New South Wales government decision-making on grey nurse shark recovery and conservation. Refined estimates of adult abundance and population trend (described in the Final Project Report) enables reduced uncertainty in recovery assessments, and supports evaluation of current management arrangements, including spatial protections for aggregation sites. Outputs • Final project report [written]

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Grey Nurse Shark aggregations". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Grey nurse sharks (Carcharias taurus) are protected in Australian Commonwealth waters. Under the EPBC Act, the eastern Australian population is listed as Critically Endangered, while the western Australian population is listed as Vulnerable. The species aggregates at particular sites along migration routes, but existing definitions and criteria for “key aggregation sites” require refinement to support consistent assessment across eastern and western Australia. This project collated existing information on recognised grey nurse shark aggregation sites and potential new sites where sharks have been observed to gather. It reviewed occupancy patterns, existing survey evidence and western population data to refine the definition of a key aggregation site and develop criteria for assessing whether sites should be listed, delisted or prioritised for further investigation. Field and data activities focused on areas where information was limited or where potential new aggregation sites had been identified. These included surveys in Victorian waters near Corner Inlet using ROV and eDNA methods in partnership with Gunaikurnai Land and Waters Aboriginal Corporation; community engagement with dive, fishing and freediving groups to improve reporting of observations; an initial BRUV survey of a reef system in Commonwealth waters in Hunter Marine Park; expanded acoustic receiver coverage at Barwon Banks in Queensland; and review of potential aggregation sites in Western Australia. The project outputs provided Commonwealth and state management agencies with a clearer, more defensible basis for identifying and assessing grey nurse shark aggregation sites. The resulting information supported consistent evaluation of existing and potential sites, prioritisation of future surveys, and improved conservation planning for both eastern and western grey nurse shark populations. Outputs • Spatial information on key Grey Nurse Shark aggregation sites [dataset] • Final project report [written]