The UK coastal trap fisheries target two key species, European lobster Homarus gammarus (L.) and brown crab Cancer pagurus L. Their stock status is assessed periodically using size‐based, yield‐per‐recruit analysis. Fishery trends are described using landings and, where available, effort data to estimate catch per unit of effort (CPUE), nominally proportional to abundance. Despite being caught together, assessments assume that concurrent capture of these species does not distort their individual CPUE estimates. Here, an in situ experiment tested impacts of inter‐specific and intra‐specific interactions by pre‐loading baited traps with different species and observing subsequent catches. Pre‐loaded European lobster significantly reduced brown crab catches, whereas, other species produced no such effects. The findings highlight the likely inconsistency of using CPUE as an index of abundance if landings data originate from a mixed‐species fishery in which species interactions and targeting behaviour of fishers are unknown or un‐quantified.

中文翻译：

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种间和种内相互作用影响甲壳类捕捞渔业—对管理的意义

英国沿海捕捞渔业的目标是两个主要种类，欧洲龙虾Homarus gammarus（L.）和棕蟹巨蟹座pagurusL.定期使用基于规模的按产量计算的分析来评估其库存状态。使用着陆量和可能的工作量数据来描述渔业趋势，以估计每单位工作量（CPUE）的捕捞量，名义上与丰度成正比。尽管被聚在一起，评估仍假定同时捕获这些物种不会扭曲其单独的CPUE估计值。在这里，一个原位实验通过将不同种类的诱饵诱捕器预先装满并观察随后的捕获物，从而测试了种间和种内相互作用的影响。预装的欧洲龙虾可大大减少褐蟹的捕获量，而其他物种则没有这种作用。