Fisheries Research Group, The Safina Center, Honolulu, USA.
Key Traceability, Portsmouth, UK.
Sci Rep. 2023 Feb 14;13(1):2621. doi: 10.1038/s41598-023-29616-7.
Marine megafauna exposed to fisheries bycatch belong to some of the most threatened taxonomic groups and include apex and mesopredators that contribute to ecosystem regulation. Fisheries bycatch is a major threat to the conservation of albatrosses, large petrels and other pelagic seabirds. Using data sourced from a fisheries electronic monitoring system, we assessed the effects of the time-of-day and relative depth of fishing on seabird and target species catch rates for a Pacific Ocean pelagic longline fishery that targets albacore tuna with an apparently high albatross bycatch rate. Using a Bayesian inference workflow with a spatially-explicit generalized additive mixed model for albacore tuna and generalized linear mixed regression models both for combined albatrosses and combined seabirds, we found that time-of-day and fishing depth did not significantly affect the target species catch rate while night-time deep setting had > 99% lower albatross and total seabird catch rates compared to both deep and shallow partial day-time sets. This provides the first evidence that night-time setting in combination with fishing deep reduces seabird catch risk and may be commercially viable in this and similar albacore tuna longline fisheries. Findings support evidence-informed interventions to reduce the mortality of threatened seabird bycatch species in pelagic longline fisheries.
海洋大型动物因渔业副渔获物而暴露于捕捞活动中，它们属于受威胁程度最高的分类群之一，包括对生态系统调节起重要作用的顶级掠食者和中型掠食者。渔业副渔获物是信天翁、大海燕和其他远洋海鸟保护的主要威胁。本研究利用渔业电子监测系统获取的数据，评估了捕捞时间和相对水深对一种以箭鱼为目标、兼捕大量信天翁和其他海鸟的太平洋远洋延绳钓渔业中，海鸟和目标物种渔获率的影响。本研究采用贝叶斯推断工作流程，建立箭鱼的空间显式广义加性混合模型，以及信天翁和海鸟组合的广义线性混合回归模型，结果表明，捕捞时间和水深并未显著影响目标物种的渔获率，而夜间深海设置与深、浅部分日间设置相比，信天翁和总海鸟的渔获率分别降低了>99%。这首次证明夜间深海设置可降低海鸟的捕捞风险，在这种箭鱼延绳钓渔业或类似的渔业中可能具有商业可行性。本研究结果支持了采取循证干预措施减少远洋延绳钓渔业中受威胁海鸟副渔获物死亡的措施。
