The paper provides a preliminary examination of catches and data holdings for bycatch species in the Ross Sea toothfish fishery. Bycatch species composition varied between management areas; however landings of most species groups were generally highest in SSRUs 88.1H and 88.1I in the S70 management area. As found in other areas of the Convention, macrourids were the most commonly observed bycatch group by both weight and numbers. Macrourids, skates, icefish, eel cods and morid cods comprised almost 99.5% of the total bycatch by weight. A large amount of length, weight, sex, and gonad stage data, as well as material for ageing (i.e., otoliths for finfish, whole individuals or caudal thorns for skates), has been collected for key species since 2014, in particular the starry skate Amblyraja georgiana, violet cod Antimora rostrata, the macrourids Macrourus caml and M. whitsoni, and for the most common eel cod species in the Ross Sea, Muraenolepis evseenkoi.
Based on the findings of this paper, we recommend:
- A revised data collection plan be developed to direct continued collection and support analysis of data for bycatch species. Such a plan should balance data collection with other observer commitments, and be aligned with both a revised fishery-based research plan as well as the broader objectives of the Ross Sea region Marine Protected Area Research and Monitoring Plan.
- Characterisations of inter alia recent trends in catch, effort, catch rates, and biological information should be compiled for commonly observed species so that quantitative risk assessments can be developed assess the risk of fishing on these species.
- To assist with the cataloguing and analyses of biological data:
- i) The "Revision of CCAMLR catch reporting forms" e-group explore ways to indicate whether non-otolith tissue samples where retained on the biological form; and
- ii) The e-group also explore ways to indicate whether individuals recorded in the biological form were tagged.
- That the Secretariat periodically summarise data available for bycatch species from toothfish fisheries in other areas and incorporate this information into fishery reports.