Quantitative analysis of the importance of wind-induced circulation for the spatial structuring of planktonic populations

1. Several studies have shown that wind-induced water movements have an important effect on the spatial distribution of crustacean zooplankton. However, few attempts have been made to quantify the effect of physical processes on these broad-scale patterns. Much of our understanding of this spatial structure has been based on the results of isolated surveys, which do not capture the dynamic nature of the pelagic environment. 2. In this study, we have used a combination of high-speed sampling (at a spatial resolution of 240 m) and spatial data analysis to quantify the factors influencing the horizontal spatial structure of the Daphnia galeata population in Windermere. 3. The results show that lake-wide circulation patterns, as indicated by water temperature, account for 29–47% of the basin-scale spatial variance in D. galeata abundance. However, these patterns are highly dynamic and change in response to the prevailing weather. This lack of temporal persistence means that the results of single-survey sampling campaigns must be interpreted with caution.