Project number: 2016-044
Project Status:
Budget expenditure: $328,743.00
Principal Investigator: Campbell Davies
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 2 Oct 2016 - 29 Apr 2018


Annual estimates of SBT spawning stock abundance are required to assess the status and productivity of the stock. Prior to the original CKMR study, there was no direct index of abundance of the spawning population The majority of the difference in the estimates of spawning stock status between the 2011 and 2014 stock assessments was due to the influence of the CKMR data, in combination with the 1990’s conventional tagging data. This reduced the overall uncertainty in spawning biomass and natural mortality and, therefore, identified a number of unproductive (pessimistic) parameter combinations as implausible. These were removed from the reference set of OMs (Anon 2014)

The schedule of implementation of the CCSBT MP includes a full stock assessment is scheduled for 2017. As a result of decisions by CCSBT to discontinue the Aerial Survey and move to gene-tagging, the CCSBT will initiate development of a new MP in 2017. Candidate MPs will be tested (in 2018) and a final MP selected using the OMs reconditioned in 2017 as part of the full stock assessment. The aim of this FRDC project is to provide a time-series of absolute abundance estimates of spawning potential from 2002 to 2013 for direct use in the CCSBT OMs. This abundance trajectory of the spawning potential of the stock will be independent of CPUE and catch data from the main fisheries, and will be an important input to domestic and international consideration of the stock status and performance of the rebuilding plan.

If the CKMR information is not available for the 2017 assessment, it is highly unlikely to be incorporated for testing of Candidate MPs. This would mean the CCSBT MP used to recommend future global TACs would not be “calibrated” with the most recent information on the status and recent trend in the spawning stock.


1. Process archived tissue samples, extract DNA and genotype (~16,000 individuals, 2006-2014)
2. Combine genotypes from 1 with those from related CCSBT project (2015-2016)
3. Estimate time series of total adult abundance, spawning potential and total mortality on the spawning population
4. Report outcomes to SBTMAC, AFMA and CCSBT Scientific Committee for incorporation into 2017 update of the CCSBT Operating Model.

Final report

ISBN: 978-1-925994-04-9
Author: Campbell Davies
Final Report • 2020-06-16 • 3.04 MB


This report presents the results of the first application of Close-Kin Mark-Recapture (CKMR) using both Parent-Offspring Pairs (POP) and Half-sibling Pairs (HSP). This application to Southern Bluefin Tuna (SBT) has been successful, providing a decadal time series of absolute abundance, total mortality and selectivity of adults. The method and the results have been reviewed and accepted by the Scientific Committee of the Commission for the Conservation of
Final Report • 2020-06-16


This research has provided the world’s first scientifically tested management procedure for Southern Blue Fin Tuna (SBT) using DNA sequencing and genetic tagging to manage stock levels and deliver significant economic benefits.
Final Report • 2020-06-16 • 82.79 KB
papers 2016-044.pdf


The following working papers from this project were submitted to the CCSBT

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