Threadfin Salmon under the microscope
Scientists will use DNA, ear-bones and parasites to help unravel information about movement patterns of two important inshore fish species across northern Australia in a new three year project.
The information from the project will help fisheries managers determine the appropriate way to sustainably manage threadfin salmon across northern Australia and ultimately benefit all fishers.
King and blue threadfin salmon are favoured table fish caught by commercial, recreational and indigenous fishers across tropical and sub-tropical Australia. Scientists suspect that there may be several different populations of each of these two species throughout Queensland, the Northern Territory and Western Australia.
“Surprisingly little research has been carried out on these important species and so there are information gaps even on their basic biology” says principal investigator Mr David Welch, a Queensland Department of Primary Industries & Fisheries biologist based at James Cook University.
“Understanding the population structure and movements of these two species is critical to ensure they are managed sustainably.”
Three complementary techniques will be used to determine the extent that fish of each species interact with those from other areas.
Professor Bob Lester of the University of Queensland will look at tiny parasites carried by each fish in their stomachs and gills to detect if there are differences in fish from different regions.
Dr Stephen Newman of the WA Department of Fisheries will use the ear-bones, or ‘otoliths’, to examine for trace elements.
“The trace elements in the otoliths can tell us about the movements of each fish and where they have been living over their lifetimes” says Dr Newman.
These elements will also be compared among fish from different regions to identify population structure using an independent technique to the parasites.
In the third method, Dr Lynne van Herwerden of James Cook University will examine the DNA and genetic markers to identify differences among populations of blue and king threadfins.
This will help determine whether there are separate genetic populations of each species across northern Australia. This is important to identify possible sources of past (and therefore potential future) replenishment of populations.
This new multi-agency research project is a collaboration between the QDPI&F, the Northern Territory Department of Primary Industry, Fisheries & Mines, James Cook University, the University of Queensland, and the Department of Fisheries, Western Australia.
It will be co-ordinated by the Fishing & Fisheries Research Centre at James Cook University and supported by funding from the Australian Government’s Fisheries Research and Development Corporation.
Contact: David Welch 07 4781 5114 Email: david.welch@jcu.edu.au
Stephen Newman Ph: 08 9203 0192 Email: Stephen.Newman@fish.wa.gov.au
JCU Media Liaison, Jim O’Brien 07 4781 4822 or 0418 892449
