Project number: 2016-003
Project Status:
Completed
Budget expenditure: $454,390.00
Principal Investigator: Mike A. Steer
Organisation: SARDI Food Safety and Innovation
Project start/end date: 30 Jun 2016 - 29 Jun 2019
Contact:
FRDC

Need

Additional management action is needed to ensure that the King George Whiting stocks of Spencer Gulf and Gulf St. Vincent/Kangaroo Island regions return to a sustainable status and to manage recreational catches within the allocated catch shares in the Management Plan for the South Australian Marine Scalefish Fishery. Although spawning spatial closures have been identified as a management option for the fishery, the relative benefit of their proposed locations (i.e. Corny Point and Tapley Shoal) in protecting spawning productivity is unknown. Similarly it is not understood how key spawning grounds south of the gulf support the regional stocks. There is, therefore, a fundamental need to characterise these spawning aggregations from an ecological, economic and social perspective to ensure that they are designed and implemented appropriately.

The current ‘transitional-depleting’ status assigned to the gulf stocks is predominantly based on commercial catch and effort data integrated with limited information from the recreational and charter boat sectors. Given the recent changes in the fishing fleet dynamics which includes an increase in the allocation of catch by the recreational sector (by ~ 10%) (see Giri & Hall, 2015) and the increased pressure on spawning fish, there is a need to develop a fishery-independent means of assessing biomass to enhance future assessments of stock status.

Given the multi-sectorial use of the resource and South Australia’s government commitment in maintaining quality recreational fishing opportunities; ensuring the continued supply of commercially harvested premium seafood; and to uphold allocated shares among the sectors, there is a need to develop and foster a representative steering committee that is committed to achieving the objectives, outcomes, adoption and extension of this project.

Objectives

1. To determine key King George Whiting spawning areas through the southern gulf systems of South Australia.
2. To quantify links between larval source and sink populations.
3. To develop a fishery-independent technique that provides the most accurate estimate of spawning biomass (i.e. daily egg production method) for King George Whiting and integrates with the on-going assessment and management of the resource.
4. To evaluate the potential benefits of strategic management options to protect the spawning stock and ensure the sustainable harvest of King George Whiting.

Final report

ISBN: 978-1-876007-28-7
Authors: M.J. Drew T. Rogers M.J. Doubell J. Charles A. Oxley R. McGarvey J. Smart S. Catalano A. Redondo Rodriguez A.J. Fowler D. Matthews M.A. Steer
Final Report • 2020-08-13 • 3.79 MB
2016-003-DLD.pdf

Summary

This study investigated the spawning dynamics of King George Whiting (Sillaginodes punctatus) in South Australia’s southern gulfs and Investigator Strait. King George Whiting is one of the most valuable and iconic coastal finfish species of southern Australia. In South Australia’s Marine Scalefish Fishery, it is considered a ‘primary’ species, attracts the highest finfish price per unit weight for commercial fishers, and is highly sought after by the recreational and charter boat sectors. This study applied a modified daily egg production method (DEPM) to develop a fishery-independent method to estimate King George Whiting biomass to supplement and underpin the future fishery-dependent estimates of stock.  

Related research

Environment
Environment
Blank