Spatial and temporal changes in copepod zooplankton communities of Lake Tanganyika

Abstract

Pelagic Copepoda zooplankton in Lake Tanganyika were sampled over two years at three localities. When the data from both years were pooled, post-naupliar cyclopoids formed 76% of the pelagic post-naupliar Copepoda off Bujumbura, 83% off Kigoma and 62% off Mpulungu. During both sampling years, dry weight biomass of post-naupliar copepod stages decreased at sampling sites in the order Bujumbura > Kigoma > Mpulungu. Cyclopoids off Kigoma showed a clear seasonal pattern with one abundance peak in October/November and another at the end of the wet season in April/May. At other locations, neither cyclopoids nor calanoids showed clear seasonal pattern. Correlation of seasonal biomass was low between the first and second dry seasons, and between the first and second wet seasons in all the sampling localities and in all the zooplankton groups. The yearly mean post-naupliar copepod dry weight biomass was estimated as 3.1 g dw m-2 off Bujumbura, 2.1 g dw m-2 off Kigoma and 1.5 g dw m-2 off Mpulungu.