This record provides an overview of the NESP Marine and Coastal Hub project "Updating knowledge of Australian white sharks". For specific data outputs from this project, please see child records associated with this metadata.
The white shark is listed as vulnerable and migratory under Australia’s Environment Protection and Biodiversity Conservation Act 1999. The national White Shark Recovery Plan 2013 sets out research and management actions necessary to support the recovery of the white shark in Australian waters.
Previous research funded by the National Environmental Science Program (NESP) provided updated estimates of white shark breeding population size and trend. However, the results were based on modest data sets and were limited by some critical knowledge gaps in relation to pupping and juvenile nursery areas, and uncertainty about how populations are connected between eastern and south-western Australia.
Recent unpublished work has raised the prospect of a single Australian population. The White Shark Recovery Plan 2013 has identified a critical need for a quantitative assessment of population trends and evidence of any recovery of the white shark in Australian waters. This project will provide an update and reduce uncertainty regarding the status, trends, and population structure of white sharks in Australian waters. Specifically, it will focus efforts to identify critical habitats and biologically important areas for white sharks and improve the understanding of population status through advancing close-kin mark recapture research.
Three project sub-components will involve:
• Investigating the feasibility of filling knowledge gaps about juvenile and pupping areas and adult movements;
• Investigating population structure to resolve mixing/connectivity questions; and
• Updating population estimates based on significant new data.
The project approach will comprise of:
(1) A pilot study to assess the effectiveness of tagging adult females (>4.5 metres) and juveniles (>2 m) throughout the southern-western white shark range. Genetic samples will be gathered from around Australia and sought from South Africa and New Zealand to conduct a comprehensive update of white shark stock structure.
(2) Using an expanded tissue sample set from New South Wales (~1000 samples) to update and refine estimates of adult population size and population trend for the eastern white shark population. Juvenile numbers will be estimated using data from the New South Wales shark management program. Additional samples from South Australia and Western Australia will be combined with previous samples in the southern-western population to refine estimates of population size.
(3) Population estimates undertaken using close-kin mark-recapture, a technique that combines advanced genetics and statistical modelling to infer population demographics by identifying close-kin-pairs (parent-offspring or half-siblings) among a collection of sampled animals.
Outputs
• New genetic samples and sequencing data for white sharks [dataset]
• Tracking data derived from 12 PAT tags [dataset]
• Final technical report (including recommendations for systematic future research to assist in identifying additional critical habitat for the south-western white shark population) [written]
