Comparison of physico-chemical parameters with macroinvertebrate and vertebrate fauna of Lake Ogelube and Lake Ojii, Opi-Agu, south-eastern Nigeria

Abstract

The physico-chemical parameters of water provide crucial information on the condition of a waterbody at a point in time. Physico-chemical parameters determine the primary and secondary productivity of an aquatic ecosystem. Data on water temperature, pH, turbidity, water depth, total dissolved solids, total hardness, biochemical oxygen demand, dissolved oxygen, chloride, nitrate and phosphate, together with information on the aquatic macroinvertebrate and vertebrate species composition and abundance were collected for two Nigerian lakes, Lake Ogelube and Lake Ojii at Opi-Agu. The physico-chemical parameters were analysed using standard methods. Macroinvertebrate and vertebrate (Actinopterigii and Amphibia) species composition and abundance in the lakes were correlated with the physico-chemical parameters. Temperature, depth, biochemical oxygen demand and phosphate were significantly higher in Lake Ojii than in Lake Ogelube, while pH, turbidity and nitrate were significantly higher in Lake Ogelube (p < 0.05). In total, 1 442 animals were collected from the lakes of which 1 101 were macroinvertebrates and 341 vertebrates. The family Libellulidae (Order: Odonata) and the species Coptodon zillii (synonym: Tilapia zillii) (Gervais, 1848) (Perciformes: Cichlidae) were the most abundant macroinvertebrate and vertebrate taxa, respectively. Libellulidae were negatively associated with biochemical oxygen demand, temperature, turbidity, phosphate and chloride and Coptodon zillii was positively associated with dissolved oxygen.