Effects of Environmental Variables on Some Aquatic Biota of Jabi Lake, Federal Capital Territory, Abuja

Abstract

The presence of environmental variables above regulatory permissible limit especially, high levels of toxic substances and heavy metals in freshwater bodies represents a global public health issue. Aquatic ecosystems are critical components of the global environment and essential contributors to biodiversity and ecological productivity. The effects of environmental variables on some aquatic biota of Jabi Lake was studied from January, 2022 to December, 2023 using a combination of insitu and laboratory analyses. Seven stations were selected; the tributaries (3 stations), the confluent station and 3 stations within the Lake, to determine the physico-chemical, nutrients and biological characteristics based on the activities in and around the various stations. Physico-Chemical parameters measured were: Atmospheric temperature, Water temperature, pH, Dissolved Oxygen (DO), Turbidity, Water Electrical Conductivity (WEC), Water current, Biological Oxygen Demand (BOD), Total Dissolved Solid (TDS), Alkalinity, Chemical Oxygen Demand (COD) and Nitrite. Nutrients: Phosphate and Nitrate. Metals: Copper (Cu), Iron (Fe), Lead (Pb), Zinc, Chromium and Cadmium. Some of the parameters were within the regulatory permissible limit while few above the standard. There were significant differences (P<0.05) between these parameters, within the months, stations and seasons. The result of biotic fauna recorded shows composition and abundance of 4 phyla, 9 classes, 25 families and 45 species. Temperature has the most pronounced effect on the distribution and abundance of aquatic fauna, followed by DO in the CCA analysis. The Shannon Weiner species diversity index is 1.14. Pearson correlation ®between fauna family and hydro-chemical parameters shows that phosphate was significant at P< 0.05 followed by COD, EC and BOD.