Spatial and Temporal Distribution Patterns and Their Underlying Causes

Temporal developments of dissolved nutrients, phytoplankton and zooplankton in the water column were investigated on different time scales from 1994 to 1996. Measurements of single tidal cycles allowed to assess the fate of some species in the Wadden Sea. Dissolved nutrients showed some regularly recurring patterns, which could be explained by the tidal mixing of water bodies with different nutrient concentrations. Seasonal cycles of the nutrients, phytoplankton and zooplankton showed a large interannual variability. Timing and extension of algal blooms influenced the occurrence of many meroplanktonic larvae. Most of the algal species in the backbarrier system of Spiekeroog were part of the phytobenthos and the phytoplankton.