Project number: 2019-103
Project Status:
Completed
Budget expenditure: $11,328.74
Principal Investigator: John Stewart
Organisation: NSW Department of Primary Industries
Project start/end date: 14 Jan 2020 - 31 Jul 2020
Contact:
FRDC

Need

Yellowtail Kingfish is a high priority species for recreational fishers and the basis of an important commercial fishery in NSW. The biological stock structure is reasonably well understood, with genetic analyses showing that the population in Western Australia is genetically distinct from the population along the eastern and southern Australian coasts (Commonwealth, Queensland, New South Wales, Victorian, Tasmanian and South Australian waters) and New Zealand. Tagging studies have confirmed movements between Australia and New Zealand and South Australia to NSW. Therefore Yellowtail Kingfish are assessed through the Status of Australian Fish Stocks (SAFS) initiative at the biological stock level, being two stocks - Eastern Australia and Western Australia.

The most recent (2018) SAFS assessment for the Eastern Australian biological stock of Yellowtail Kingfish was ‘Undefined’, due mainly to knowledge gaps around the degree of mixing throughout this stock which spans more than 3,000 km of coastline. Reasonable data for assessment exists only within NSW, and uncertainty around whether an assessment of that component of the stock reflected the entire stock resulted in an ‘Undefined’ status, with a recommendation that this uncertainty be resolved.

Yellowtail Kingfish within NSW has been assessed as ‘Growth Overfished’ (2003/04 to 2013/14), and current evidence indicates a Depleted stock. There are ongoing discussions within NSW about appropriate management changes that may assist recovery; however these are hampered by the ‘Undefined’ status in SAFS.

The FRDC National Priority 1 aims to reduce the percentage of ‘Undefined’ stocks within SAFS, which also has an objective of providing a roadmap to recovery for ‘Depleted’ stocks. To address both of these and to promote better and more collaborative monitoring, assessment and management across all relevant jurisdictions, there is a clear need to review existing knowledge across the entire stock and to identify areas of uncertainty that require addressing.

Objectives

1. Review the available data and management regimes for the south-eastern Australian stock of Yellowtail Kingfish from each relevant jurisdiction
2. Review the reasons for the ‘Undefined’ status in SAFS
3. Discuss appropriate spatial scales for assessment and management across the south-eastern Australian biological stock
4. Identify knowledge gaps required to be filled in order to produce a defined stock status for SAFS
5. Discuss cross-jurisdictional assessment and management options for Yellowtail Kingfish

Final report

ISBN: 978-1-76058-450-4
Authors: John Stewart Julian Hughes Holly Gunton
Final Report • 2021-06-30 • 895.32 KB
2019-103-DLD.pdf

Summary

The project facilitated cross-jurisdictional and cross-sectoral discussions on aspects of the Eastern Australia biological stock of Yellowtail Kingfish.  Several knowledge gaps relating to biological and life-history parameters, as well as reliable data on the recreational fishery across all jurisdictions, were found to be inhibiting assessment, and therefore management, of this stock.  Knowledge gaps common across jurisdictions included understanding patterns of movement and connectivity throughout the stock, and reproductive patterns such as main spawning areas and times.  It was noted that this lack of information was one reason for differing management arrangements (minimum legal lengths and bag limits) between jurisdictions.  A survey of long-term, highly experienced commercial, recreational and charter fishers in NSW was done to provide feedback on data to be used in assessing stock status.  Comments from these knowledgeable fishers resulted in several reconstructed catch history scenarios being used in the assessment, in addition to gathering observations on long-term changes to the fishery.  As a result significant progress was made on the Status of Australian Fish Stocks (SAFS) assessment for 2020.  The Eastern Australian stock of Yellowtail Kingfish for 2020 was classified as a ‘Sustainable’ stock, noting that until knowledge around population dynamics, in particular the distribution and movements of the spawning stock and the source of juveniles, is improved that the assessment will remain highly uncertain.

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