Sub-Antarctic Extensive Research
The Atlas Cove conducts an annual Random Stratified Trawl Survey (RSTS) to assess the juvenile stocks of Patagonian toothfish and Mackerel icefish in the HIMI Fishery. This survey takes around 20 days to complete and is done so on company time, targeting a number of different bottom or strata types around Heard Island and the Kerguelen Plateau, which allows scientists from the Australian Antarctic Division (AAD) to analyse species composition in numerous locations. The information collected on the population structure and abundance of Patagonian toothfish and Mackerel icefish during these surveys is a critical input to stock assessments of these species.
Both the Austral Leader II and the Southern Champion have actively participated in benthic camera projects for the AAD. These projects are designed to assess if our fishing operations are negatively impacting the seabed. These cameras can be mounted on trawl nets, longlines and pots, so we can be confident that our fishing operations are not adversely impacting the benthic ecosystem, or if they are, to improve our operations to ensure the protection and sustainability of the numerous benthic ecosystems in our fisheries. Results from this work found that 98.5% of biodiversity on the seafloor in the HIMI fishery remains undisturbed from fishing.
All vessels actively participate in a toothfish tag and release program. Toothfish are a very resilient fish as they have no swim bladder. This evolutionary adaption means they can be brought up to the surface from over 2,000m deep, be tagged, released, and are then able to travel back down to the depths of the Southern Ocean unaffected. This program requires us to tag 1 toothfish for every 1,000kg caught, meaning we tag and release around 4,000 toothfish per year! We have currently tagged and released over 30,000 toothfish over the years. Once a tagged toothfish is retrieved on board, the tag is removed by the observer and taken back for analysis by the AAD. Information gathered in these tags includes growth rates and the spatial movement of the particular fish.
Austral’s Rhys Arangio was awarded a Nuffield Scholarship for 2012, sponsored by Woolworths and the Fisheries Research & Development Corporation. This scholarship allowed Rhys to travel internationally to liase with experts in his aim to find appropriate mitigation measures against marine mammal depredation of toothfish off longlines.