Sciences marines : recherche et développement

Abstrait

Effects of Cadmium Exposure on Reproduction and Survival of the Planktonic Copepod Centropages ponticus

Ensibi Cherif, Olivier Pringault, Wifek Hannaoui and Mohamed Nejib Daly Yahia

Heavy metal pollution is a growing environmental problem in marine coastal waters; for this reason the monitoring of water pollution needs the availability of test-species able to furnish reliable and cheap results. From this point of view, copepods are important test organisms owing to their wide distribution and for their key-position within the food web. As Centropages ponticus seems to be a promising target-species in ecotoxicology. The present study assesses the toxic effects of cadmium (Cd) on survival and reproductive performance of C. ponticus. A microcosm experiment was carried out for this study. Copepods were exposed to cadmium that ranged in concentration from 0.1 to 200 µg Cd.L-1 and effects were examined after 24 hours. The results show that treatments with cadmium significantly affect survival in copepods at concentration equal or above 0.2 μg.L−1. In order to assess sublethal effects of cadmium on reproduction; the test organisms were exposed to four nominal Cd concentrations 0, 0.2, 0.4, 1 µg.L-1. The results indicated that egg production decreased with the increase of metal concentration. An increase of the Cd concentration reduced the number of hatched nauplii. Thus, survival and reproduction in C. ponticus as a model test species could be effective physiological markers to monitor marine metal pollution.