The time series of relative abundance and age structure from the Ross Sea shelf survey provides information about year class strength, variability, and autocorrelation, and hence is an important input into the Ross Sea region toothfish stock assessment. This was the thirteenth survey in the time series and for the first time, the 2024 survey was not completed as planned. Only 12 stations in the core survey area (10 in stratum A, and 2 in stratum B) and McMurdo Sound (the biennially surveyed stratum N), could be completed because freeze-up occurred following an anomalously lengthened commercial season, which led to logistical challenges for the vessel. We recommend that future surveys plan to survey the core strata first, to ensure that the age and abundance data can continue to be used in the Ross Sea region stock assessment. Should lengthened commercial seasons continue, then a more fundamental solution may be required for future surveys, and this will be considered when a new multi-year research plan is submitted next year.
A VME trigger occurred on 3 of the 5 line segments at the first station sampled in McMurdo Sound. The vessel notified the CCAMLR Secretariat that it had encountered a VME (initially under CM 22-07 and triggering an automatic closure to future fishing) and ceased research fishing in that location, as specified in CM 22-06 paragraph 9. Relatively little coral or sponge were caught as bycatch on the longline, and little is known about the attraction of Astrotoma agassizii to baited longlines. We recommend that this area and the extent of the VME should be considered for further investigation, such as with underwater cameras, when a new multi-year research plan is submitted next year and encourage study of attraction and movement towards food sources for this species. We further request that Members that may have underwater video or camera footage of the benthic habitat in this area please contact New Zealand.