The distribution of organochlorine pesticides in marine samples along the Indian Ocean coast of Kenya

The concentrations of organochlorine residues of lindane, aldrin, proportional to-endosulfan, dieldrin, endrin, p,p'-DDE, p,p'-DDD and p,p'-DDT in samples of seawater, sediment, fish and seaweed from different locations along the coast of Kenya an discussed,of of two years. All in relatiort to the geographical location of the sampling sites and potential sources of residue, sediment samples were found to contain very low levels of organic carbon except those sampled River that had high (4.7%) organic carbon due to greater primary activity. Most of the pesticides residues (112 samples analysed in 1997 and 258 analysed in 1998/99) were detected in fish, water, sediments and seaweed. The concentration of some residues was higher during the wet season than the dry season in 1997, but no marked seasonal variation was observed in 1998/99. Lindane, aldrin, p,p'-DDT and p,p'-DDE were the most frequently observed residues in all samples while proportional to-endosulfan, dieldrin, p,p'-DDD and endrin were either present in low concentrations or absent in most samples. Water samples had the lowest concentrations of residues (range 0.503 - 9.025 ng g(-1)). Sediments had the second highest levels of pesticides residues with a range of 0.584 - 59.00 ng g(-1) while fish lipid content had the highest levels of residues in 1989/99 with p,p'-DDT concentration of 1011 ng g(-1) and 418 ng g(-1) p,p'-DDD in Siganus rivulatus.