Management agencies are often charged with providing fisheries that lead to angler participation. Catch rate is one of the primary drivers of angler participation but can be influenced by a suite of factors, including population structure (e.g., density and size structure). The complexity of understanding how population structure influences angler catch rate is typified in kokanee Oncorhynchus nerka fisheries. Previous research suggests that angler catch rates of kokanee are positively influenced by fish density and total length. However, that research was based on data collected using size‐selective midwater trawls. Due to the potential limitation of previous research, we sought to (1) understand the relative bias of midwater trawls and gill nets for describing the size structure of kokanee available to anglers and (2) re‐evaluate the influence of fish density and fish length on angler catch rates in kokanee fisheries. Midwater trawl, gill‐net, and creel data were collected on five prominent kokanee fisheries throughout Idaho in 2016 and 2017. Catch composition and percent overlap of midwater trawls, gill nets, and angler‐caught fish were compared to understand the efficacy of midwater trawls and gill nets for representing the size structure of kokanee available to anglers. In addition, the influence of kokanee density and length on angler catch rates was evaluated. Midwater trawls primarily sampled small kokanee (<330 mm) and exhibited little overlap with angler‐caught fish, whereas gill nets sampled more large fish (>330 mm) and exhibited higher overlap with angler‐caught fish when compared to midwater trawls. Fish length was not positively associated with angler catch rates. However, fish density exhibited a positive relationship with angler catch rates. Our results highlight the importance of gear choice for understanding how kokanee populations function and elucidate the tradeoffs associated with population density, fish length, and resulting kokanee fisheries.

中文翻译：

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人口密度和长度结构对科卡尼渔业中垂钓者捕获率的影响

管理机构通常负责提供导致钓鱼者参与的渔业。渔获率是钓鱼者参与的主要驱动力之一，但受一系列因素影响，包括种群结构（例如密度和大小结构）。在kokanee Oncorhynchus nerka中，典型的理解种群结构如何影响垂钓者捕获率的复杂性渔业。先前的研究表明，科卡尼的垂钓者捕获率受鱼类密度和总长度的积极影响。但是，该研究基于使用尺寸选择性中水拖网收集的数据。由于先前研究的潜在局限性，我们试图（1）了解中水拖网和刺网的相对偏差，以描述垂钓者可利用的kokanee的大小结构，以及（2）重新评估鱼密度和鱼长的影响钓鱼在科卡尼渔业中的捕获率 在2016年和2017年，在爱达荷州的五个著名的科卡尼渔业中收集了中水拖网，刺网和鱼架数据。中水拖网，g网的捕获量和重叠百分比 比较了垂钓者和垂钓者捕获的鱼类，以了解中水拖网和刺网对垂钓者可用的kokanee大小结构的功效。此外，评估了kokanee密度和长度对垂钓者捕获率的影响。与中水拖网相比，中水拖网主要采样小柯卡尼（<330 mm），与垂钓者捕获的鱼几乎没有重叠，而g网对大鱼（> 330 mm）采样较多，与垂钓者捕获的鱼具有更高的重叠。鱼的长度与垂钓者的捕获率没有正相关。但是，鱼的密度与垂钓者的捕获率呈正相关。我们的结果凸显了选择齿轮的重要性，因为这对于了解柯卡尼种群的功能以及阐明种群密度，鱼类长度，