Survey of Zooplanktons and Macro-Invertebrates of Gbedikere Lake, Bassa Local Government Area, Kogi State Nigeria

Abstract

Zooplankton and macro-invertebrates samples were collected weekly from three sampling stations at the Gbedikere Lake, Bassa Local Government Area, Kogi state, Nigeria from July to September 2008. Prior to sampling, Temperature of surface water, Secchi disc transparency, pH and dissolved oxygen concentration were evaluated. Zooplanktons were sampled using plankton net, while macro-invertebrates were sampled using a scoop net and hand picks. The result revealed that zooplankton was made up of Protozoa (43.30%), Rotifera (37.40%), Copepoda (17.0%) and Cladocera (2.30%), while macro-invertebrates were represented by ten groups that include Coleoptera (2.44%), Diptera (48.85%), Ephemeroptera (2.59%), Hemiptera (9.59%), Odonata (29.07%), Trichoptera (0.91%), Plecoptera (0.30%), Arachnida (2.13%), Annelida (2.89%) and Nematoda (1.22%). The lake could be classed as eutrophic as indicated by the diversity of zooplankton and macro-invertebrates. Keywords: Zooplankton, macro-invertebrates, micro-crustaceans, Gbedikere Lake, Nigeri