King threadfin stock assessment—Queensland east coast

Chart of 2019 Queensland east coast stock assessment biomass estimates and key management actions for king threadfin

© Queensland Government

Chart of estimated recreational harvest for Queensland east coast king threadfin from 1945 to 2019

© Queensland Government

Chart of estimated commercial harvest for Queensland east coast king threadfin from 1936 to 2019

© Queensland Government

Why did we assess the king threadfin east coast stock?

In 2020, Fisheries Queensland completed a stock assessment using the most current biological data, and commercial and recreational catch data to:

  • determine the sustainability of fish stocks
  • inform management decisions
  • inform the development of a harvest strategy.

This assessment estimated that the number of adult king threadfin (spawning biomass) was between 54% and 69% of unfished levels for each of the East Coast Assessment Regions in 2019. A region in the far north (AR1) was not assessed due to very small harvest.

How was the stock assessment conducted?

The 2019 assessment used a stock assessment model called Stock Synthesis, one of the most widely used and tested stock assessment models in the world and is currently used by CSIRO and other Australian fisheries jurisdictions.

A lack of data available for the 2002 assessment caused biomass models to fail and used commercial harvest to produce a potentially useful management target for the whole east coast. The 2019 stock assessment included up-to-date data on recreational and commercial catch and effort, as well as biological data such as fish length and age, allowing a successful biomass model for 4 assessment regions on the east coast.

Findings from the independent review

As best practice, Fisheries Queensland conducts independent reviews of stock assessments and other scientific reports on a regular basis.

An independent review of the king threadfin stock assessment was conducted by Dr Neil Klaer, a former CSIRO fisheries scientist. The reviewer supported the conclusions of the stock assessment results and agreed that the assessment has been competently constructed and is suitable given the available data. He made some suggestions for improvements, including alternative options for catch rate calculations and handling the way king threadfin catchability (the proportion of the stock taken by an operator per day) may be changing over time. The authors have considered these recommendations and will address them in future assessments.

Next steps for fishery management

An east coast inshore fishery working group has been formed to provide advice on the operational aspects of the management of the east coast inshore fishery. The working group includes representatives from commercial, recreational and charter sectors, seafood processors and wholesalers, Indigenous representatives, the conservation sector and the Great Barrier Reef Marine Park Authority.

Read more information on the working group.

The working group will meet in early 2022 and will discuss the results from this stock assessment. This may include reviewing catch limits in line with the East Coast Inshore Fishery Harvest Strategy.

More information

Access the Stock assessment of king threadfin in Queensland report, review and response to the review.