Improving Aquaculture and Fisheries Productivity by Reducing Impacts of Pesticides Contamination in Ahero Fishponds, Kisumu County

Abstract

Pesticides contamination in water, sediments, soil and Tilapia zili from fishponds in Ahero were investigated to assess the extent of pollution and likely health hazards from fishpond environment. The use of pesticides in agriculture for improving farm productivity has resulted in increased residues in sediments, soil and water. Sediments and water have become a major concern as they are the feeding and breeding points for aquatic organisms. Some of the pesticide residues are toxic to the environment and as a result threaten fish productivity and have great potential risk to human health. Various studies have been carried out previously around River Nyando basin and Winum Gulf of Lake Victoria on physico-chemical parameters, heavy metals and organochlorine pesticides. However, the focus of these studies has been based on OCPs and other inorganic pollutants in lake and river waters around the Lake Victoria basin. Little attention has been given to farmed fish in Ahero irrigation scheme despite the fact that it is located along the Nyando basin and has the potential of being exposed to residues of various pollutants deposited from the highlands which come as a result of flood during rainy season. The main objective of this study was to improve aquaculture productivity in the country and contribute to sustainable food security by reducing the impact of pesticides contamination in fisheries production. Fish, water, sediments and soil samples were obtained from the localities of fishponds, extracted and analysed for physical-chemical parameters, heavy metals, nutrients and Organochlorine pesticides (OCPs). Both short rain (dry) and long rain (wet) seasons were covered during sampling stage. The 17 OCPs were analysed using gas chromatograph, while atomic absorption spectrophotometer was used to analyse the heavy metals. Some of the Physical-chemical parameters analysed included electrical conductivity, TDS, TSS, pH and temperature. Nitrites, nitrates and phosphates levels were analysed with the use of UV-vis