水産養殖研究開発ジャーナル

概要

Seasonal Variations of Trace Metal Concentrations in the Soft Tissue of Lithophaga Lithophaga Collected from the Bizerte Bay (Northern Tunisia, Mediterranean Sea)

Ferdaous Jaafar Kefi, Anwar Mleiki, Jihen Maâtoug Béjaoui and Najoua Trigui El Menif

The concentration of four trace metals (Zn, Cu, Pb and Cd) was determined in the soft tissue of the date mussel Lithophaga lithophaga that is specifically and strictly protected by international law. Samples were collected from the Bizerte bay in the northern coast of Tunisia. Comparisons were made on the basis of season and sex. Trace metal concentration decreased in the order Zn > Cu > Pb > Cd. The average concentration was 54.15 ± 23.037, 3.429 ± 1.453 and 1.809 ± 2.252 μg g^-1 dry weight, for Zn, Cu and Pb respectively. Cd was not detected in all samples. Significant temporal variation was observed for Zn, Cu and Pb (P < 0.05). There is no significant difference between females and males except for Zn in spring and Pb in winter. Analyses of the condition index (CI) revealed the presence of a single reproductive cycle per year affecting metal bioaccumulation of L. lithophaga. The main objective of metal analysis was to provide useful information about trace metal pollution in the Tunisian date mussel L. lithophaga which will enable to evaluate the potential effect of the Bizerte Marina Project on this species.