Heavy Metal Content of Some Selected Shellfish from Oil Producing Communities in Bayelsa State, Nigeria

Abstract

The level of heavy metals in marine ecosystem has been intensively studied during recent years as these hazardous substances could be accumulated in the biota. Generally, the presence of contaminants in shellfish is as a result of human activities such as industrial, agricultural wastes, crude oil exploration and spillage and this has pose a significant threat to humans’ health and other animals feeding on them over the years. In this study, some heavy metals levels in shellfishes sourced from the rivers of Otuoke community in Ogbia local Government Area, Oporoma community in Ekeremor Local Government Area and Sangana community in Brass Local Government Area, all in Bayelsa state, were investigated and the samples were prepared according to Food and Agricultural Organization of United Nation FAO (1994) standard test methods. The total mean of cadmium, Lead, and mercury ranges between 0.00mg/g to 0.002mg/g in periwinkle, prawn and oyster gotten from the three communities and was compared with the WHO acceptable limit of 0.5mg/kg – 1.0mg/kg. This could have been due to increased rainfall during the period of this study which in turn increase water levels and hence reduced or dilute the heavy metal concentration and thus less risk of bioaccumulation or possibly that the oil producing communities from where the shellfish where obtained might have possibly be link to lack of cases of oil spillage over a recent past before the commencement of the study. This study therefore advocates that periwinkle, prawn and oyster which are shellfishes used for this study from the rivers in these communities are safe for human consumption with respect to heavy metals load especially within the raining season when this study was conducted.