Effect of Some Environmental Variables on the Community Structure of Zooplankton in Tungan Kawo (Wushishi Dam), Niger State, North Central, Nigeria

Abstract

Water samples and zooplankton were collected monthly for five months in three sites in Wushishi Dam, Niger State. The study was undertaken to look at effect of some environmental variables on zooplankton community in the dam. Dissolved oxygen (DO) was highest in site 1 with mean value of 2.60±0.248 mg/l. There was no significant difference (p>0.05) in DO, BOD and pH recorded among the months and sites. Temperature and transparency showed significant difference (p<0.05). Four orders of zooplankton were recorded namely; Cladocera, Copepoda, Calanoida and Rotifera, consisting of 2467 individuals. The CCA showed poor relationship between some zooplankton species distribution and some measured environmental variables (DO, conductivity, temperature and pH). Some of the organisms like Eucyclops elegance, Leptodiaptomus minutus and Megacyclops viridis in June (site 2 and 3) were associated with pH while Cyclops scutiser was weakly associated with conductivity. Megacylops viridis was closely associated with BOD and more of M. viridis were sampled in site 2 and 3 which have a high BOD value. Abundance of Cyclops scutiser which has been attested to be of medical importance showed the significance of the dam. Detailed research is recommended to further prove this study, especially the use of zooplankton as bioindicators.

Key Words: Water quality parameters, Megacylops viridis, Bioindicator, Cyclops Scutiser, Medical importance, Wushishi Dam, Niger State