SEASONAL VARIATION IN THE PHYSICO-CHEMICAL PARAMETERS OF OWALLA RESERVOIR, OSUN STATE, NIGERIA

Abstract

Fishes are threatened due to unwanted changes in the physical, chemical and biological properties of water. The
need for efficient monitoring of the Physico-chemical parameters in Owalla reservoir is becoming pertinent with
reports of a decline in fish production due to unsustainable exploitation. The water quality of the reservoir was
monitored to reveal the extent of its contamination, and suitability for fishes and other aquatic organisms. The
Physico-chemical characteristics; temperature, pH, dissolved oxygen, alkalinity, total hardness, turbidity, and
conductivity of water samples from selected points in the reservoir were analysed using standard methods for
twenty-four (24) months. From the Data obtained the mean values for; temperaturewas25.16 ± 0.34 oC, pH 7.44
± 0.26, dissolved oxygen 7.31 ± 0.36 mg/L, alkalinity 64.11 ± 0.46mg/L, total hardness 41.72 ± 0.78 mg/L,
turbidity 34.95 ± 5.67 NTU and Conductivity 61.87 ±7.01µSc. The values obtained indicated that the reservoir is
not under heavy stress as the mean values of the determined parameters were found to be within the permissible
limits.