This record provides an overview of the scope and research output of the NESP Marine Biodiversity Hub project "Estimation of population abundance and mixing of southern right whales in the Australian and New Zealand regions". For specific data outputs from this project, please see child records associated with this metadata. -------------------- A comprehensive understanding of the population abundance and degree of spatial connectivity of southern right whales in Australian waters is currently lacking. This limits assessments of the species recovery and understanding of the nature and degree of difference between the south-eastern and south-western Australian populations. This project will provide, for the first time, an abundance estimate of the total Australian population of southern right whales. It will also investigate the connectedness of whales that utilise breeding areas on the eastern, southern and western coasts of Australia. Information provided by this project will allow the Australian government to better evaluate progress made against the Conservation Management Plan for southern right whales and ensure conservation efforts for the species are effectively coordinated at the regional level. Planned Outputs • Data summaries for populating models used to estimate abundance and connectivity • An estimate of population abundance at the national scale and associated uncertainty • An evaluation of movement and spatial mixing across southern Australia

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]