IMAS scientists are helping to provide a better understanding of one of the world’s most remote fisheries.
As part of an FRDC-funded project, a large team of researchers are helping to reveal how the Patagonian toothfish (Dissostichus eleginoides) population is distributed across the Australian and French Territories on the sub-Antarctic Kerguelen Plateau. (Right, Patagonian Toothfish. Credit: Marius Kapp)
Now in its third year, the research is a collaboration with researchers from the Institute for Marine and Antarctic Studies (IMAS), the Australian Antarctic Division (AAD), France’s Museum National d’Histoire Naturelle, and Australian Long Line and Austral Fisheries, and will ensure the sustainable harvest of Patagonian toothfish in Australia’s sub-Antarctic waters.
Due to be completed in early 2018, the project is developing tools to assess spatially-structured and multi-jurisdictional toothfish fisheries and undertake ageing of toothfish.
IMAS researcher Dr Bryn Farmer (Photographed below, viewing the sectioned otolith of a Patagonian toothfish) said that study would provide important information to assist with the management of the fishery.
“All fishing vessels have observers on board who collect toothfish biological information, release and recapture tagged fish and extract otoliths (ear bones),” Dr Farmer said.
“The otoliths are sectioned and the number of growth rings are counted under a microscope to estimate fish age.
“The age data is an important data source in stock assessment models as it permits researchers to track year classes (cohorts).
“The data collected from tagged toothfish is used to estimate toothfish movement.
“This is challenging because our data only provides the location of release and recapture of tagged fish and these observations depend on the spatial locations of fishing. The estimates will inform our understanding of the structure and connectivity of the toothfish population on the Kerguelen Plateau.
“We then evaluate how fish movement and fishing patterns effect the population estimates from our current assessment models and develop methods to account for potential biases.
“This work will enhance the harvesting of Patagonian toothfish while ensuring that the fishery in Australia’s sub-Antarctic waters is sustainable” Dr Farmer said.
More information on Australia’s management of Southern Ocean fisheries can be found here: http://www.antarctica.gov.au/science/conservation-and-management-research/southern-ocean-fisheries/fish-and-fisheries