Abstract Hypoxic conditions in both freshwater and marine habitats have a significant effect on the distribution of fish in the water column, resulting in some fishes aggregating near the edges of the hypoxic zone. These aggregations may increase fish susceptibility to fishing gears, with attendant effects on stock assessment inferences. We investigated how hypoxic conditions influenced catch rates of yellow perch (Perca flavescens) in both fishery-independent bottom trawls and stationary commercial trap nets. Specifically, we examined how the presence of hypoxia affected trap net catch rates and how hypoxia interacted with hypolimnion thickness to modify trawl catch rates. Bottom trawl catch rates were significantly higher in hypoxic conditions than in normoxic conditions, and in each of these scenarios catch rates declined as hypolimnion thickness increased. By comparison, trap net catch rates had a dome-shaped response to the duration of hypoxia with the highest catch rates occurring at intermediate levels. Increased catch rates in hypoxic conditions potentially causes yellow perch population models, which rely on both trap net and trawl indices, to overestimate abundance and could result in overfishing.

中文翻译：

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缺氧会增加水体分层对鱼类分布的边缘效应

摘要 淡水和海洋栖息地的缺氧条件对鱼类在水体中的分布有显着影响，导致一些鱼类聚集在缺氧区边缘附近。这些聚集可能会增加鱼类对渔具的敏感性，从而对种群评估推断产生影响。我们调查了缺氧条件如何影响独立于渔业的底拖网和固定商业诱捕网中黄鲈（Perca flavescens）的捕获率。具体来说，我们研究了缺氧的存在如何影响陷阱网捕获率，以及缺氧如何与水下层厚度相互作用以改变拖网捕获率。低氧条件下的底拖网捕获率显着高于常氧条件，并且在这些情景中的每一种情况下，捕获率都随着水下层厚度增加而下降。相比之下，捕集网捕获率对缺氧持续时间呈圆顶形响应，最高捕获率发生在中等水平。在缺氧条件下增加的捕获率可能会导致黄鲈种群模型（依赖于诱捕网和拖网指数）高估丰度并可能导致过度捕捞。