The Blue Catfish Ictalurus furcatus is a popular sport fish in its native range and a prolific invasive species in its nonnative range. Low‐frequency electrofishing (LFE) is effective for sampling Blue Catfish, and development of standardized LFE protocols for sampling Blue Catfish is critical for monitoring and management of their populations. However, standardized sampling for Blue Catfish can be difficult because their habitat use is variable among seasons and habitats, and LFE is affected by a suite of abiotic factors. To quantify this variation, our objectives were to determine how Blue Catfish LFE catch (1) differs during spring and summer sampling seasons, (2) is affected by environmental variables, and (3) relates to their habitat use. To do so, we conducted a telemetry study and systematic random LFE sampling in Lake Dardanelle, Arkansas, in the spring and summer of 2016. We compared the numbers, capture rates, and size structure (proportional size distribution index of quality‐size fish) of telemetry‐located and LFE‐captured Blue Catfish in distinct habitats and found that habitat use was heterogeneous but capture rates were proportional to habitat use. Blue Catfish catch increased with conductivity and decreased with flow velocity; catch also differed among habitat types, among reservoir zones, and between seasons (spring/summer). Understanding how spatiotemporal differences in habitat use contextualize the effects of LFE catch will improve sampling protocols for Blue Catfish.

中文翻译：

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环境变化和栖息地使用对蓝Cat鱼低频电鱼捕捞率的影响

蓝Cat鱼Ictalurus furcatus是在其本地范围内流行的运动鱼，在其非本地范围内是多产的入侵物种。低频电钓鱼（LFE）对蓝Blue鱼采样有效，而标准化蓝FE鱼采样LFE协议的开发对于其种群的监测和管理至关重要。但是，对蓝habitat鱼进行标准化采样可能很困难，因为它们的栖息地使用情况在季节和栖息地之间会有所不同，并且LFE受一系列非生物因素的影响。为了量化这种变化，我们的目标是确定蓝Cat鱼LFE捕获量（1）在春季和夏季采样季节之间如何不同；（2）受环境变量影响；以及（3）与它们的栖息地使用有关。为此，我们于2016年春季和夏季在阿肯色州达达尼尔湖进行了遥测研究和系统的随机LFE采样。我们比较了遥测定位和LFE捕获的蓝Cat鱼在不同生境中的数量，捕获率和大小结构（质量大小鱼的比例大小分布指数），发现生境使用是异质的，但捕获率与生境使用成比例。蓝Cat鱼的捕获量随电导率增加而随流速降低；栖息地类型，水库区之间以及季节（春季/夏季）之间的捕获量也有所不同。了解栖息地使用的时空差异如何根据LFE捕捞的影响而定，将改善蓝Cat鱼的采样规程。遥测和捕获LFE的蓝Cat鱼在不同生境中的大小和大小结构（质量大小鱼的比例大小分布指数），发现生境使用是异类的，但捕获率与生境使用成比例。蓝Cat鱼的捕获量随电导率增加而随流速降低；栖息地类型，水库区之间以及季节（春季/夏季）之间的捕获量也有所不同。了解栖息地使用的时空差异如何根据LFE捕捞的影响而定，将改善蓝Cat鱼的采样规程。遥测和捕获LFE的蓝Cat鱼在不同生境中的大小和大小结构（质量大小鱼的比例大小分布指数），发现生境使用是异类的，但捕获率与生境使用成比例。蓝Cat鱼的捕获量随电导率增加而随流速降低；栖息地类型，水库区之间以及季节（春季/夏季）之间的捕获量也有所不同。了解栖息地使用的时空差异如何根据LFE捕捞的影响而定，将改善蓝Cat鱼的采样规程。