Diel vertical migration of zooplankton in a hypertrophic shallow temperate lake, Germany

Abstract

Zooplankton as important links in the food web of aquatic ecosystems have been studied extensively. In current literature their diel vertical migration (DVM) is a highly discussed issue. In this investigation DVM by zooplankton is studied in a hypertrophic shallow lake in Germany. The objectives of the study were to see if DVM by zooplankton occurs in shallow lakes such as Lake Dagowsee, the possible overlap in DVM of Leptodora kindtii, an invertebrate predator, and zoopankton, and the effect of wind action on DVM. It was found out that DVM of zooplankton occurs in Lake Dagowsee despite the limited range of depth for migration, wind action can influence DVM and L. kindtii poses a complex situation in relation to DVM behaviour of zooplankton in Lake Dagowsee. Finally, further studies are suggested with regard to DVM variation between different species, size and hybrid groups of Daphnids, and identification of the light sensitive range that can cue DVM of zooplankton and L. kindtii in temperate and tropical waters.

Key words/phrases: Daphnia spp., Diaphanosoma brachyurum, Eudiaptomus gracilis, Lake Dagowsee, zooplankton

SINET: Ethiop. J. Sci. Vol.27(1) 2004: 33-44