Impact of aquaculture development on water quality of fish ponds in gatundu North and south sub-counties, Kenya

Abstract

Aquaculture development in Kenya has increased in the recent past due to Government support, however, information on its influence on water quality is scanty. This study looked at the influence of fish culture on water quality in fish ponds. Water samples were collected from pond inlets and fish ponds and physico-chemical parameters analyzed. Means of measured parameters at the pond inlets were; Temp(21.27±3.31 °C), DO(4.45±0.73mg/l), EC(27.38±17.21µS/cm), TDS(368.61±135.21mg/l), pH(7.31±0.45), N-NO3(2.06±2.38mg/l) and PO4-P(0.29±0.41mg/l) while mean values inside the ponds were; Temp (23.58±3.85 °C), DO(4.89±1.09mg/L), EC(34.63±19.50µScm-1) TDS(493.13±136.67mg/l), pH(7.68±0.50), NO3(2.76±2.35mg/L) and PO4-P (1.71±1.50mg/L). Values of measured parameters were within acceptable limits for aquaculture as per WHO standards. All parameters significantly increased in pond water as compared to inlet water showing that aquaculture was contributing to deterioration of the water quality in fishponds. This calls for effluent treatment, regular monitoring and sensitization of farmers on good aquaculture practices.