Abstract In the U.S. West Coast groundfish bottom trawl fishery, Pacific halibut (Hippoglossus stenolepis) bycatch can impact some fishers’ ability to fully utilize their quota shares of groundfishes. In this study, we compared the catch efficiency for Pacific halibut and four commercially important groundfish species between an illuminated and non-illuminated trawl. The illuminated trawl caught significantly fewer Pacific halibut and sablefish than the non-illuminated trawl. For Dover sole (Microstomus pacificus), petrale sole (Eopsetta jordani), and lingcod (Ophiodon elongatus), the illuminated trawl caught fewer individuals than the non-illuminated trawl. However, this catch difference was not statistically significant. Physiological data collected on Pacific halibut caught in illuminated and non-illuminated trawls show blood levels of cortisol, a stress hormone, were significantly higher in fish caught in the illuminated trawl than in the non-illuminated trawl in the absence of differences in condition factor or fat content. While our results have obvious implications for the West Coast groundfish bottom trawl fishery, our findings could also have potential applications in Alaska and British Columbia, Canada trawl fisheries where Pacific halibut bycatch occurs.

中文翻译：

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使用人工照明减少美国西海岸底层鱼底拖网中的太平洋大比目鱼兼捕

摘要 在美国西海岸底层鱼底拖网渔业中，太平洋大比目鱼（Hippoglossus stenolepis）兼捕会影响一些渔民充分利用其底层鱼类配额份额的能力。在这项研究中，我们在照明和非照明拖网之间比较了太平洋大比目鱼和四种具有商业重要性的底层鱼类的捕获效率。与非照明拖网相比，照明拖网捕获的太平洋大比目鱼和黑鲈鱼明显减少。对于 Dover 鳎 (Microstomus pacificus)、petrale鲇 (Eopsetta jordani) 和 lingcod (Ophiodon elongatus)，照明拖网捕获的个体少于非照明拖网。然而，这种捕获差异在统计上并不显着。在照明和非照明拖网中捕获的太平洋大比目鱼的生理数据显示血液中的皮质醇水平，在条件因素或脂肪含量没有差异的情况下，在光照拖网中捕获的鱼中的应激激素显着高于非光照拖网。虽然我们的结果对西海岸底层鱼底拖网渔业有明显的影响，但我们的发现也可能在阿拉斯加和加拿大不列颠哥伦比亚省的拖网渔业中具有潜在的应用，这些地方发生太平洋大比目鱼兼捕。