Preliminary report of the trial on net monitoring cable/warp seabird-strike mitigation measures conducted by the Chinese F/V FU XING HAI during the 2023/24 fishing season

The Chinese krill fishing vessel F/V FU XING HAI conducted her first trial of net monitoring cable seabird-strike mitigation measure during the 2023/24 fishing season in accordance with CM 25-03(2023). A set of mitigation devices were deployed to minimize seabird strike from various cables, including net monitoring cables, trawl warps and additional gear securing ropes/wires. The net monitoring cable (NMC) was deployed from the stern of the vessel, and a snatch block was used to keep the NMC close to the hull thus reducing its aerial extent. Trawl warp was deployed using derrick at midship on each side of the vessel. ‘Netting sock’ and colored streamer lines were used to minimize seabird strike from the warp. Colored pennants were attached to those additional ropes or wires used for securing the pumping hoses, trawl warps and derricks. Fishing operation was conducted in Subarea 48.2, 48.1 and 48.3 from 4 February to 20 August 2024. During the trial, a total of 356.7 hours on-vessel seabird strike observation were conducted, amounting to 12.1% of the 2945.9 hours total active fishing time. From May to June, a total of 127.8 hours on-vessel observation were conducted, amounting to 17.5% of the 730.7 hours total active fishing time. A total of 47 seabird strikes, including 27 heavy ones, were encountered, but no mortality was observed. Most strikes occurred on trawl warp, and none was on net monitoring cable. The result suggests that the snatch block was highly effective for mitigating seabird strike on net monitoring cable, and other mitigation devices were also effective while improvement is possible. Bird abundance observation showed that, in most occasions, there was none or only a few birds were present during nighttime. Interactive analysis showed that the occurrence of seabird strikes was significantly influenced by seabird abundance around the vessel and the natural light conditions, and the wind direction relative to the vessel may also be relevant: bird strikes was more likely to encounter when the vessel was trawling with lateral-wind with abundant seabirds around during twilight period. On-shore observation with video footage will be made, and a detailed report will be submitted to the WG-IMAF or any other meeting as specified by the SC-CAMLR-43 in 2025. It is suggested that the severity definition or classification of bird strike be reviewed to reflect the underlying cause of the seabird contact with the water.