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This study examined the effects of different tail-section towing configurations on tori line aerial-extent performance using at-sea trials on Chinese tuna-fishing vessels. Three tori line configurations were evaluated at representative operational vessel speeds of 4.5, 6.0, and 8.2 kt. These included the baseline streamer configuration, a plastic-cone configuration (20 m long drag section with four 45 cm plastic cones installed at intervals of 2 m), and a drogue configuration (20 m long drag section with 50 cm drogue at terminal end, followed by 10 m of resin rope and a 200 mm float). A sensitivity analysis was also conducted using low-, moderate-, and high-drag scenarios, and the drag force generated by each configuration was estimated. The results showed that tail-section towing configuration clearly affected the aerial deployment of the tori line. The drogue configuration achieved the best aerial-extent performance at all tested vessel speeds, and met or exceeded the 100 m benchmark under all test conditions. The baseline streamer configuration ranked second. These findings indicate that both the magnitude and stability of the drag generated by the tail-section towing configuration are important factors influencing tori line aerial-extent performance.

A cumulative impact analysis framework integrating species habitat suitability and fishing effort data, stratified by gear type, was used to assess bycatch risk for threatened and protected species in China's seas and adjacent waters. Across all taxonomic groups examined, including seabirds, sea turtles, marine mammals, elasmobranchs, bony fishes, and benthic invertebrates, the highest bycatch risk was concentrated between 23°N and 25°N. For marine mammals and sea turtles, elevated risk was concentrated along China's southeastern coast, extending through inshore waters from the Yangtze River Estuary south to 20°N, with trawls and gillnets contributing most significantly to risk. Seabird bycatch hotspots were primarily located around islands, bays, and estuaries north of 20°N, where gillnets posed the greatest threat. Elasmobranchs experienced high bycatch risk from the Taiwan Strait to the Yangtze River Estuary and around Jeju Island, and were the most vulnerable taxa group overall. Bycatch risk for benthic invertebrates was largely restricted to narrow nearshore areas and was associated primarily with dredging activities. The study also found that marine protected areas generally exhibited lower bycatch risk than surrounding waters.

This study quantified spatial overlap between seabirds and industrial and small-scale coastal longline fisheries in the eastern Pacific Ocean, as well as overlap between seabird utilization distributions and areas where seabird bycatch mitigation is mandated by the Inter-American Tropical Tuna Commission (IATTC). Species with the highest overlap with fisheries, a proxy for bycatch risk, included non-breeding adult black (Procellaria parkinsoni) and white-chinned petrels (P. aequinoctialis), Chatham (Thalassarche eremita), Buller’s (T. bulleri), Antipodean (Diomedea antipodensis antipodensis), and Salvin’s (T. salvini) albatrosses, and breeding waved albatrosses (Phoebastria irrorata). The IATTC mitigation area appeared to encompass most core habitat in the eastern Pacific for the seabird species considered, with the notable exception of foraging black petrels, which largely occurred outside this area.