During WG-IMAF-2022 the results of the net monitoring cable (NMC) trials undertaken during the 2020/21 and 2021/22 seasons were presented in papers WG-IMAF-2022/10 and WG-IMAF-2022/11 respectively. The Working Group subsequently recommended that the three vessels that had undergone the trial be granted a derogation from CM 25-03 provided they maintain a coverage level of at least 5% of active fishing time (SC-CAMLR-41, Annex 8, Para. 5.41). It went on to recommend that these vessels should provide a report on the development and use of any mitigation measures to WG-IMAF-2023 and, following the mortality of four whales, report on the development of mitigation measures to reduce the risk of entanglement and by-catch of marine mammals (SC-CAMLR-41, Annex 8, Para. 4.41). This report summarises the results of the NMC observations from the three vessels under the derogation over the 2022/23 season and gives an update on any modifications to the mitigation measures used for both the NMC and the cetacean exclusion devices.
The observations followed the procedures agreed for the trial during season three and consisted of both on deck and video observations while at sea. During the monitoring period of 188 days, this led to 961 hours of coverage over 8,926 hours of trawling, a total observation effort of 10.8%. During this time 89 strikes were observed with no mortalities. Of these, 54 were observed on the NMC, the majority of which were aerial strikes and the bird was seen to fly away, apparently unharmed. Fifty of these strikes occurred on a single vessel with just over half (27) occurring over a five-day period between 29/04/2023 and 03/05/2023. No further whale interactions with the net .where observed.