SEASONAL VARIATION OF SOME PHYSICO-CHEMICAL CHARACTERISTICS OF SHIRORO LAKE, NIGER STATE, NIGERIA

Abstract

The main purpose of this study was to assess seasonal variation of some physicochemical parameters of Shiroro lake water. Physicochemical parameters influence the abundance of species composition, diversity, stability, production and physiological condition of indigenous population, hence its usefulness in accessing water quality. Water samples were taken monthly for twenty-four (24) months from five (5) stations in the lake, stations selected based on the entry points of effluent. There were variations in the mean values of physico-chemical parameters observed, (air temperature, water temperature, biological oxygen demand, alkalinity, electrical conductivity,pH and carbon (iv) oxide) were not significantly different (P>0.05) between the stations while significant difference (P<0.05) were noticed between stations for dissolved oxygen, hardness, transparency,phosphate and nitrate Seasonal variations in mean values of all the physico-chemical parameters were significantly different except that of water temperature. Dry season mean values of air temperature, water temperature, dissolved oxygen, biological oxygen demand, electrical conductivity, hardness, transparency and phosphate were higher than rainy season mean values while nitrate, pH, alkalinity and carbon (iv) oxide had their mean values higher in the rainy season. There were no difference (P>0.05) between some physico-chemical parameters mean values recorded in year 1 and year 2 of the study for phosphate, air temperature, transparency and nitrate, while significant difference (P<0.05) was observed between year 1 and year 2 for electrical conductivity, alkalinity, hardness chloride, dissolved oxygen, biological oxygen demand water temperature and carbon(iv)oxide. All the physico-chemical parameters studied were within World Health Organization (WHO) range set standard for optimal fish production and survival except for electrical conductivity and carbon (iv) oxide that were slightly below the set limits. The water is productive and not heavily polluted yet. The implication is that water from Shiroro Lake can support the survival, growth and rnational Journal of Applied Biological Research 2021 development of various fish species. However, it is recommended that the Lake resource should be monitored and effective management strategies put in place by responsible authorities to ensure sustainable development