IMAS Metadata Catalogue
Close-Kin Mark-Recapture
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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]