Although low‐frequency, pulsed‐DC electrofishing is considered the most effective method for sampling Blue Catfish Ictalurus furcatus in reservoirs, efforts to improve sampling efficiency have not been fully explored. Optimizing sampling duration can reduce cost and effort if shorter sample times still produce precision similar to that of longer samples. We compared several catch rate and size structure metrics from the first and second 5‐min intervals of 10‐min low‐frequency electrofishing samples for Blue Catfish in three Oklahoma reservoirs (N  = 40 sites total). The total Blue Catfish CPUE (CPUE_Total ), CPUE of preferred‐length fish (>760 mm; CPUE₇₆₀), mean TL, proportional size distribution (PSD), and PSD of preferred‐length fish did not significantly differ between sampling intervals. One reservoir had a higher proportion of 200–299‐mm fish in the second 5‐min interval; however, no other differences in length frequency or other size metrics were detected between the first and second 5‐min intervals in any reservoir. Sampling precision met the target level (relative standard error = 20) for CPUE_Total but not CPUE₇₆₀ during both the first 5 min and the full 10‐min sample at all reservoirs. Monte Carlo simulation indicated that 10 samples would be needed to achieve the target precision (relative standard error ≤ 20) for CPUE_Total and 38–65 samples would be needed for precise CPUE₇₆₀ metrics regardless of sample duration. In fisheries with moderate catch rates like those we observed (150–500 fish/h), we recommend short‐duration (i.e., 5‐min) sampling because data of the same quality can be collected with reduced cost and effort. For situations in which sampling precision is low (e.g., CPUE₇₆₀), we recommend increasing the number of replicate 5‐min samples. Using shorter sample durations provides a method for managers to obtain quality population data more efficiently, allowing time for other worthwhile management activities that would otherwise not be possible.

中文翻译：

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采样持续时间对低频电鱼捕捞蓝Blue鱼捕获率和大小结构数据的影响

尽管低频脉冲直流电捕鱼被认为是对水库蓝Blue鱼Ictalurus furcatus进行采样的最有效方法，但尚未全面探索提高采样效率的方法。如果较短的采样时间仍能产生与较长样本相似的精度，则优化采样持续时间可以减少成本和工作量。我们比较了三个俄克拉荷马州水库中蓝N鱼的10分钟低频电钓鱼样本的前5分钟间隔和后5分钟间隔的几个捕获率和规模结构指标 。蓝Cat鱼的总CPUE（CPUE _Total ），首选长度鱼的CPUE（> 760 mm; CPUE ₇₆₀），优选长度鱼的平均TL，比例大小分布（PSD）和PSD在采样间隔之间没有显着差异。在第二个5分钟的间隔中，一个水库的200-299-mm鱼的比例更高。但是，在任何储层中，第一个和第二个5分钟间隔之间没有检测到长度频率或其他尺寸指标的其他差异。在所有油藏的前5分钟和全部10分钟采样期间，采样精度均达到了CPUE _Total 的目标水平（相对标准误差= 20），但未达到CPUE ₇₆₀的目标水平。蒙特卡洛模拟表明，要达到CPUE _Total 的目标精度（相对标准误差≤20），需要10个样本，而要获得精确的CPUE _760，则需要38-65个样本指标，与采样持续时间无关。在我们观察到的中等捕获率的渔业中（150-500鱼/小时），我们建议进行短时（即5分钟）采样，因为可以降低成本和工作量来收集相同质量的数据。对于采样精度较低的情况（例如CPUE ₇₆₀），我们建议增加5分钟重复样本的数量。使用较短的采样持续时间为经理提供了一种更有效地获取高质量人口数据的方法，从而为其他有价值的管理活动留出了时间，而这些活动本来是不可能的。