Obtaining a representative sample is fundamental to the assessment of fish communities. In this study we used data from 99 different surveys of 29 artificial lakes in the Czech Republic to evaluate the precision of fish community indicator estimates based on reduced gillnet scenarios derived from triplet gillnets installed in each particular locality, depth strata and habitat. Forty-four indicators (based particularly on numbers and biomass per unit of effort – NPUE and BPUE, respectively) were compared between the full sampling design (three gillnets at every sampling location) and six reduced scenarios which were combinations removing one or two gillnets from the triplets. The whole community comparison found the accuracy (R²) between the full sampling design and reduced scenarios usually to be above 0.9. Strong accuracy was also found for species richness and mean fish weight. In individual species comparisons, accuracy above 0.75 was found for common species in a given habitat, whereas accuracy for less common species sometimes dropped below 0.5. Setting one gillnet in an appropriate depth strata and lake locality appears to be sufficient for unbiased overall NPUE, BPUE, and species composition estimates, and at the same time, reduces sampling effort and minimizes unwanted fish mortality. Capturing less common species in a given habitat is more or less accidental and additional sampling effort increased the probability of catching these species. On the other hand, methods targeting rare species of interest may be considered instead of increasing gillnet effort above the CEN standard.

获得代表性样品是评估鱼类群落的基础。在这项研究中，我们使用了来自捷克共和国29个人工湖的99个不同调查所得的数据，基于减少的刺网场景（由安装在每个特定地区，深度地层和栖息地的三重刺网衍生而来），来评估鱼类群落指标估计的精度。在完整采样设计（每个采样位置有三个刺网）和六个减少的方案之间进行了比较，将四十四个指标（分别基于单位工作量的数量和生物量，分别为NPUE和BPUE）和六个减少的方案进行了组合，这些方案从中删除了一个或两个刺网三胞胎。整个社区比较发现准确性（R ²），在完整抽样设计和简化方案之间通常要高于0.9。还发现物种丰富度和平均鱼重的准确度很高。在单个物种的比较中，在给定的栖息地中常见物种的准确性高于0.75，而不常见物种的准确性有时降至0.5以下。在适当的深度地层和湖泊位置设置一个刺网似乎足以进行无偏向的总体NPUE，BPUE和物种组成估计，同时减少采样工作并最大程度减少不想要的鱼类死亡率。在给定的栖息地中捕获不太常见的物种或多或少是偶然的，额外的采样工作增加了捕获这些物种的可能性。另一方面，