Summary
In response to a report of the incidental mortality of three juvenile humpback whales in the Antarctic krill trawl fishery in Subareas 48.1 and 48.2 during the 2021 calendar year, SC-CAMLR reconvened the Working Group on Incidental Mortality Associated with Fishing (WG-IMAF). This was the first time that the incidental mortality of a whale was reported in the krill fishery. With the intent for SC?CAMLR to better understand potential reasons for these bycatch events and to avoid them in the future it approached IWC-SC with a request to provide scientific feedback on these circumstances associated with these incidents and to nominate scientists to attend the WG-IMAF meeting. To facilitate scientific feedback, an IWC-SC intersessional group on whale entanglement/entrapment in the krill fishery was formed, and subsequently developed a report detailing advice on a range of topics, from data collection needs when whale entrapments occur through to several recommendations regarding mitigation, including avoidance of whales by fishing vessels, technologies such as excluder devices, and management measures such as 'move-on' rules. This report was reviewed by WG-IMAF which requested further assistance from IWC-SC, in particular for refining additional data to be collected by observers and crew when whale entrapments occur and, in the longer term, provision of advice for krill trawling operators to minimise whale entrapments (including development of technology to study how whales are interacting with krill trawling nets, move-on rules, etc), and on refining designs of the marine mammal exclusion device, considering a convex shape to the exclusion mesh to deflect whales (and seals) away from the net mouth.