The annual random stratified trawl survey (RSTS) of 2018 around Heard Island and McDonald Island (HIMI) in Division 58.5.2 took place from the end of March to the end of April, with the completion of 163 stations plus eight extra fine mesh hauls. The survey was conducted on the FV Atlas Cove. Sampling protocols such as the design and the duration of the hauls were similar to recent surveys, but with a new set of randomly selected station points.
The catch of Dissostichus eleginoides (Patagonian toothfish) was twice that of 2017 while the catch of Champsocephalus gunnari (mackerel icefish) was two thirds of the 2017 survey catches. The catches of the other managed bycatch species, Channichthys rhinoceratus (unicorn icefish), Lepidonotothen squamifrons (grey rockcod) and Macrourus spp. (macrourids combined) were also two to three times greater than those of last year. Catches of skates were similar to those of 2017. Invertebrate catch (including jellyfish) in the 2018 survey was 1.5 times the low value of 2017.
The calculated biomass for 2018 of the target species D. eleginoides and C. gunnari in the survey area were close to the highest estimates for the past 10 years. For the managed by-catch species C. rhinoceratus and Macrourus spp. the biomass estimate was similarly high. Conversely, the estimate for L. squamifrons has been low for the past 4 years. The 2018 biomass estimates for each of the three Bathyraja spp. (skates) were the highest in the last 10 years.
Length measurements and sex were taken for nearly 22 000 fish and for more than half of those biological measurements were also recorded. Otoliths were collected from 656 D. eleginoides and 609 individuals were tagged and released.