Response of meiofauna to petroleum hydrocarbon of three fuel oils

Oil spills are recurrent problem in marine system. Effects of oil pollution are many. The present paper evaluates the effect of Petroleum Hydrocarbon of three fuel oils on metazoan meiofauna. The results suggest significant variations in the toxic effect of three oils used. The meiofauna responded differently to crude oil, diesel and kerosene. The fauna reduced significantly (p<0.05) in all concentrations after two weeks. The reduction in crude oil was more than 50% in 25g/l, 65% in 50 g/l and 69% in 100g/l. In other cases the reduction was higher. In lower concentrations (25g/l) the more sensitive taxa such as harpacticoids, turbellaria and ostracods were more affected. The meiofauna exposed to PHC showed recovery in the last week, particularly the nematodes showing increase in number indicating their resilient nature. Other groups particularly crustacea appeared more sensitive because they reappeared and recovered much slowly. The abundance of most meiofaunal groups remained low at the end of four weeks exposure to PHC. The effect of oil on the fauna was dose dependent. The toxicity was in the order of kerosene > diesel > crude oil.