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(70-14) Integrated laboratory and field assessments of heavy metals accumulation in edible periwinkle, Tympanotonus fuscatus var radula (l.). Otitoloju, Adebayo*,1, Don-Pedro, Kio1, 1 University Of Lagos, Akoka, Lagos ABSTRACT- A combination of laboratory and field bioaccumulation experiments was employed in assessing the impact of metal-laden effluent discharges on the tissue concentrations of the heavy metals in an edible periwinkle, Tympanotonus fuscatus of Lagos lagoon. In the field experiments, Zn and Pb ions accumulated in Tympanotonus fuscatus collected from impacted stations were found to be about 10 times higher than the concentrations detected in control animals. A similar observation was also recorded in the laboratory experiment whereby the concentrations of the metals accumulated in whole body tissues of exposed animals were about 3 to 4 times higher than the concentrations detected in control animals. With respect to accumulation of Cu ions, the concentrations of the metal accumulated in Tympanotonus fuscatus was found to fluctuate continuously throughout the duration of the experiment, both under the field and laboratory experiment. The termination of metal-laden effluent discharges into the experimental creek, after 150 days of contamination, resulted in a rapid and significant decline in the concentrations of the metals detected in sediment concentration, however, the concentrations of metals accumulated in tissues of the periwinkles remained high. The significance of the observations in heavy metal pollution management in aquatic ecosystems was discussed. Key words: bioaccumulation, integrated assessment, effluent, biomonitoring |
