In October 2024, the POKER (“POissons de KERguelen”) V survey was carried out around the Kerguelen Islands in CCAMLR Division 58.5.1, with the completion of 129 valid trawl stations. The sampling design was modified compared to previous POKER surveys (2006, 2010, 2013 and 2017) to focus on Patagonian toothfish recruitment. The demersal trawl survey was conducted on the FV Atlas Cove with gear comparable to previous surveys and covered only the shelf area (up to 550 m) and Skiff bank.
A total of 25+ fish species were recorded. Length measurements were taken for 22 663 fish and a large number of samples were collected for laboratory analyses (diet, histology, taxonomy).
The total catch of the survey was 33.8 tonnes including 3.9 tonnes of Patagonian toothfish (Dissostichus eleginoides), 4.6 tonnes of unicorn icefish (Channichthys rhinoceratus) and 20 tonnes of marbled rockcod (Notothenia rossi). The catch of mackerel icefish (Champsocephalus gunnari) was low (309 kg) compared to previous surveys which can be explained by the changes in sampling design.
While the overall composition of the benthic fish community remained consistent with previous surveys, notable temporal fluctuations in species distribution and biomass were observed. Eleven species dominated the catches, including three skate species, which showed the most significant biomass increases in 2024.
Patagonian toothfish biomass remained under the long-term average but rose compared to the 2017 low. Toothfish abundance increase was stronger than the biomass increase, reflecting a demographic shift toward younger individuals and successful recruitment in recent years (2021 and 2022), especially in the northern shelf. In contrast, larger individuals remained concentrated in the southern shelf, influencing biomass estimates. The spatial and demographic heterogeneity in the shelf biomass estimates need to be accounted for when deriving recruitment index. Ongoing work aimed at estimating biomass by age class using spatially explicit models.