Seasonal Variations in Physicochemical Properties of Water, Sediment and Fish of Tiga Dam, Kano-Nigeria

Abstract

The levels of some physicochemical parameters in the dam water were determined in wet and dry seasons while the concentrations of Na, K and heavy metals (Cd, Cr, Fe, Mn, Pb, Zn) were determined in sediment, Tilapia fish (Cichlid sp) and Cat fish (Synod onus sp) during the dry season when fishing activities were high. Variations in levels of pH, conductivity, alkalinity, DO, TDS and hardness in the water samples during the wet and dry seasons were observed but were all within the acceptable limits for drinking stipulated by the World Health Organization (WHO). However, the levels of turbidity (35.7±5.5NTU/wet -16.54±0.96NTU/dry), total suspended solids (2657.9±974.3mg/l/wet – 1496.0±101.4mg/l/dry) and total solids (2694±975.2mg/l/wet -1533.2±103.1 mg/l/dry) were higher than the acceptable limits of 5NTU and 500mg/l. Concentrations of heavy metals ranged from 0.01±0.00mg/l Cd - 0.84±0.17mg/l Fe in water, 0.51±0.02mg/kg Pb - 4.37±3.17mg/kg Fe in sediment and 0.045±0.005mg/kg Mn - 0.23±0.06 mg/kg Zn in fish tissues. Significant differences in heavy metal concentrations were recorded between seasons but variations within season were statistically insignificant. The order of high accumulation of heavy metals was sediments > fish >water which indicates possible long term health implications and environmental problems.