Dynamics of benthic invertebrates in a tropical man-made lake (Volta Lake 1964—1968) Standing crop and bathymetric distribution
Archiv für Hydrobiologie Volume 73 Number 2 (1974), p. 245 - 265
published: Apr 9, 1974
ArtNo. ESP141007302007, Price: 29.00 €
During the first five years of filling of Volta Lake (in Ghana, West Africa) two major groups of invertebrates dominated the benthic fauna: ephemeropterans, especially the nymphs of Povilla adusta NAVAS, and chironomids, especially the larvae of Nilodorum brevibucca FREEMAN and Chironomus spp. Their later decline in numbers resulted in a decrease in the biomass of the benthic invertebrates in the lake. The quantitative and qualitative changes in the benthic fauna in this lake seem to be determined to a large extent by changes in the substratum due to shoreline erosion. The lowering of the oxygen discontinuity and the prolongation of periods of high dissolved oxygen content in deep water helped the bottom fauna to occupy greater depths, but did not seem to prevent the decrease in the total standing crop of benthic invertebrates in the lacustrine sector during the process of lake ageing. The major inflows may be held responsible for maintaining a high biomass of the bottom fauna in areas under their direct influence.