Experimental studies of impacts of harbour sediments resuspension to marine invertebrates larvae: Bioavailability of Cd, Cu, Pb and Zn and toxicity

The larvae of three marine species (Artemia salina, Crassostrea gigas, Paracentrotus lividus) reared within the suspended particulate phases of contaminated sediments from harbours were used in bioassays firstly to assess their ability to accumulate four metals (Cd, Cu, Pb, Zn) and secondly to show the toxicity of such rearing media by recording delays in growth and possible abnormal larval development. The results show that resuspension processes of dredged harbour sediments may induce both a release of Cd, Cu and Pb which are bioavailable for larvae (levels of bioaccumulation depending on the species) and biological perturbations, i.e. abnormal development in C. gigas and P. lividus larvae for the more contaminated sediments and growth inhibition in all three larvae for slightly contaminated sediments. The concentrations of Pb reached in the C. gigas D-shaped larvae and the P. lividus pluteus were unusually high; in contrast, Zn was not accumulated by the three species. The impact of dumping operations thus appears to depend both on the metal considered and on the larvae used in such tests. In this context, Pb seems a more worrying metal than Zn and C. gigas and P. lividus are better indicator species than A. salina larvae.