ASSESSMENT OF HEAVY METAL POLLUTION IN WARRI RIVER USING PARASITE INDEX

ABSTRACT

Heavy metals can accumulate in aquatic ecosystems as they are highly persistent and exposure to high levels can compromise the defense system of organisms making them more vulnerable to parasitic infections. In this study parasite abundance in the gills and stomach of Coptodon guineensis from three locations (Agbarho, Enerhen and Udu) along Warri River was determined. Concentration of heavy metals (Cu), Lead (Pb), Zinc (Zn), Iron (Fe) and Cadmium (Cd) in water, sediment and fish muscle were analyzed using Atomic Absorption Spectrophotometer (Model AA 500L). Heavy metals in water, sediment and fish organs were in the order: Fe>Zn>Cr=Cu>Pb>Cd. Enerhen station had the highest metal accumulated. Fishes were infected xix with parasite such as Calliphora Cochliomyia (blow fly) and (Nematode) of which Enerhen had the highest parasite abundance of (21%) compared to Agbarho and Udu stations. Histological examination of the gills and stomach revealed prominent disruption in surface epithelium and visible inflammatory cells. Continuous monitoring of heavy metal concentrations in fish species commonly eaten is recommended, as the possible accumulation of these metals can eventually pose health risk to the populace.