Abstract For many decades pelagic longline fisheries have been responsible for the deaths of large numbers of seabirds worldwide. Baited hooks deployed onto the sea surface attract seabirds to fishing vessels leading to attacks on baits, capture and death by drowning. An alternative is to deploy baits underwater where they are less detectable, more difficult to reach and less likely to be taken by seabirds. In 2010 and 2012 proof-of-concept experiments were conducted in the Uruguayan pelagic longline fishery with a newly developed device designed to set baits underwater. The experiments examined the differences between setting baits at the sea surface and setting baits underwater with regard to the abundances of seabirds following the vessel, incidences of attacks on baits and mortality. Underwater setting led to marked reductions in the numbers of seabirds following the fishing vessel and attacks on baits, the behavioural precursors to mortality. Mortality rates of seabirds on baits set to the relatively shallow depth of 4 m were 87% lower than on baits set at the surface. No seabirds were caught on baits released 10 m underwater, a reduction of 100% compared to the surface setting mortality of 11.6 birds/1000 hooks. No differences were detected between the two setting methods in the catch rates of target and non-target fish species. The evidence from the experiments, combined with the known dive depths of the white-chinned petrel (Procellaria aequinoctialis), a deep diving, difficult-to-deter species, suggests that baits released 10 m underwater could reduce the incidental mortality of albatrosses and petrels to negligible levels.

中文翻译：

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通过隐身（水下）设置诱饵钩可以防止远洋延绳钓渔业中信天翁和海燕的意外死亡

摘要 几十年来，远洋延绳钓渔业一直是全球大量海鸟死亡的罪魁祸首。部署在海面上的诱饵钩将海鸟吸引到渔船上，导致对诱饵的攻击、捕获和溺水死亡。另一种选择是在水下部署诱饵，在那里它们不易被发现，更难以触及，也不太可能被海鸟捕获。2010 年和 2012 年，在乌拉圭远洋延绳钓渔业中进行了概念验证实验，使用了一种新开发的装置，旨在在水下设置诱饵。实验检查了在海面设置诱饵和在水下设置诱饵之间在跟随船只的海鸟数量、攻击诱饵的发生率和死亡率方面的差异。水下环境导致跟随渔船和诱饵攻击的海鸟数量显着减少，这是导致死亡的行为先兆。使用设置在 4 m 相对较浅深度的诱饵的海鸟死亡率比设置在水面的诱饵低 87%。在水下 10 m 处释放的诱饵没有捕获海鸟，与 11.6 只鸟/1000 个鱼钩的水面沉降死亡率相比降低了 100%。在目标和非目标鱼类的捕获率方面，两种设置方法之间没有检测到差异。来自实验的证据，结合已知的白颏海燕（Procellaria aequinoctialis）的潜水深度，这是一种深潜的、难以阻止的物种，