The aim of the study was to assess the suitability of a plankton net (diameter of 60 cm, mesh size of 500 µm) and a column sampler (length of 200 cm, diameter of 5 cm) for estimating the density of zooplankton predatory species (Neomysis integer, Leptodora kindtii, Cercopagis pengoi). Nocturnal sampling was performed once a month (May–November 2018) in the Vistula Lagoon (southern Baltic) in the range depth of 1.3–3.6 m. Statistical analysis indicated no significant differences between the N. integer and C. pengoi density estimated by the two sampling gears. In the case of L. kindtii, the mean density obtained by the column sampler was higher when analyzing all samples together and/or deep-water samples only (p < 0.02). However, no such differences were found at shallow stations i.e. up to ca. 2 m in depth. It was assumed that the more suitable sampling equipment for estimating zooplankton abundance in a shallow, well-mixed transitional (brackish) basin is the column sampler. This type of gear, so far used mainly for sampling of micro and mesozooplankton, allows the simultaneous nocturnal collection of the entire zooplankton size spectrum, including representatives of large predatory species. The suitability of light traps for qualitative studies of zooplankton species responding positively to light under the high turbidity of the Vistula Lagoon was also investigated. The traps proved to be most useful for N. integer (100% frequency), and much less for L. kindtii (46.2%) and C. pengoi (27.3%).

这项研究的目的是评估浮游生物网（直径60厘米，网眼尺寸500微米）和柱状采样器（长200厘米，直径5厘米）的适用性，以估算浮游动物捕食性物种的密度（Neomysis integer，Leptodora kindtii，Cercopagis pengoi）。每月（2018年5月至11月）在维斯杜拉泻湖（波罗的海南部）进行一次夜间采样，采样深度为1.3-3.6 m。统计分析表明，由两个采样齿轮估计的N. integer和C. pengoi密度之间没有显着差异。在L. kindtii的情况下，当一起分析所有样品和/或仅分析深水样品时，柱采样器获得的平均密度更高（p <0.02）。然而，在浅水站（即至多约2千米）没有发现这样的差异。深度2 m。假定更浅的采样设备是用于估计浅水，充分混合的过渡（微咸）盆地中浮游动物丰度的采样设备。到目前为止，这种类型的齿轮主要用于对微小浮游生物和中游浮游动物进行采样，它可以同时夜间收集整个浮游动物大小谱图，包括大型掠食性物种的代表。还研究了捕光器是否适合在维斯杜拉泻湖的高浊度下对光做出积极反应的浮游动物种类的定性研究。事实证明，陷阱对于N. integer（频率为100％），而L. kindtii（46.2％）和C. pengoi（27.3％）则要低得多。