ABSTRACT
The studies on zooplankton communities and physico-chemical characteristics of Obazuwa Lake, Ovia North East, Edo State was carried out from March to August, 2019; in order to investigate species composition, abundance and diversity of zooplankton and the changing physico-chemical environment of the lake. Three sampling stations were chosen; the physico-chemical and biological characteristics were determined using standard methods, procedures and instruments. Some physical and chemical parameters were studied. Among these are: Air temperature, Water temperature, Depth, pH, Turbidity, Conductivity, Total Dissolved Solids, Total Suspended Solids, Total Solids, Nitrate-nitrogen, Phosphate-phosphorus, Ammonium, Sulphate, Water Hardness, Dissolved Oxygen, Biological Oxygen Demand, Sodium, Calcium, Potassium, Magnesium and Iron which varied with months and seasons. Analysis of variance indicated no significant difference between stations (p>0.05) except for iron which was significantly different (p <0.05) across the three stations. A total of fifteen (15) zooplankton species were encountered in the lake amongst these were 3 rotifers, 3 cladocerans, 8 copepods and 1 diptera. The general diversity using Shannon Wiener and Margalef’s indices for zooplankton showed higher diversity in decreasing order of stations 1>2>3 and 1> 3 >2 respectively. Water quality of the lake is influenced by runoffs and athropogenic activities such as tree felling, hunting and farming. The water of the lake is unsuitable for drinking purposes in terms of most of the physico-chemical characteristics analysed. Hence, there is need for an effective anthropogenic inputs control programme in the lake.
