To better understand anthropogenically induced shifts of lake nutrient dynamics and subsequent consequences for fish and their zooplankton food sources, an increased spatial and temporal resolution of zooplankton monitoring data is needed. The Zooscan, an instrument mainly used in marine research, enables digitalization of zooplankton samples, and thereby substantially decreases the effort for zooplankton analysis. We present Zooscan analyses of zooplankton from the water column and in whitefish (Coregonus sp.) stomachs from Lake Starnberg (Germany, Central Europe), a large oligotrophic pre-alpine lake. Digitalized manual and automated analyses of important zooplankton parameters such as abundance, species composition, size development and reproductive measures of different taxa are given. The obtained results from automated and manual Zooscan analyses allow drawing conclusions on population dynamics, size developments and zooplankton food preferences by whitefish. In particular, we highlight the advantages of assessing reproductive cycles based on the documentation of egg-bearing individuals of e.g. cladocerans, which are of less importance in marine environments. While the results of automated analysis of stomach content were generally inaccurate, manual validation of digitized images was efficient for identification. Digitized images offer the possibility of fast access and convenient storage of zooplankton samples.

为了更好地了解人为引起的湖泊养分动态变化以及对鱼类及其浮游动物食物来源的后续影响，需要提高浮游动物监测数据的空间和时间分辨率。Zooscan 是一种主要用于海洋研究的仪器，可实现浮游动物样本的数字化，从而大大减少浮游动物分析的工作量。我们展示了来自水柱和白鲑（Coregonus ）的浮游动物的 Zooscan 分析sp.) 来自施塔恩贝格湖（德国，中欧）的胃，这是一个大的贫营养高山前湖。给出了浮游动物重要参数的数字化手动和自动分析，例如不同类群的丰度、物种组成、大小发育和繁殖措施。从自动和手动 Zooscan 分析中获得的结果可以得出关于白鲑种群动态、大小发展和浮游动物食物偏好的结论。特别是，我们强调了根据卵生动物的记录来评估生殖周期的优势，例如枝角类动物，这在海洋环境中不太重要。虽然胃内容物的自动分析结果通常不准确，但数字化图像的手动验证对于识别是有效的。