Allometric relationships in the bioconcentration of heavy metals by the edible tropical clam Gafrarium tumidum

• Published in: Science of The Total Environment
• Main Authors: Hedouin, Laetitia, Metian, Marc, Teyssie, Jean-Louis, Fowler, Scott, Fichez, Renaud, Warnau, Michel
• Other Authors: Marine Environment Laboratories Monaco (IAEA-MEL), International Atomic Energy Agency Vienna (IAEA), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), UR 103 Camélia, Institut de Recherche pour le Développement (IRD), Station Marine d'Endoume, Université de la Méditerranée - Aix-Marseille 2
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: MUSSEL MYTILUS-EDULIS; ECHINOID PARACENTROTUS-LIVIDUS; CRASSOSTREA-GIGAS THUNBERG; METALLOTHIONEIN SYNTHESIS; BODY-SIZE; MACOMA-BALTHICA; SEASONAL-VARIATIONS; BIVALVE MOLLUSKS; TRACE-ELEMENTS; PATELLA-ASPERA; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Crassostrea gigas
• Online Access: https://hal.science/hal-01438822; https://doi.org/10.1016/j.scitotenv.2005.10.022

International audience Although metal contamination is a problem of major concern in the lagoon of New Caledonia due to intense mining activities conducted on land, very little is known on the metal ecotoxicology of local marine organisms. The clam Gafrarium tumidum was investigated to assess its usefulness as a bioindicator species of metal contamination in this lagoon. More particularly, allometric relationships between metal accumulation and clam size were determined for five common metals in New Caledonian lagoon waters (Cd, Cr, Co, Zn and Ag) using a highly sensitive radiotracer technique. Experimental results showed that allometric relationships were dependent on the element and on the body compartment considered. As a rule, allometric relationships of metal concentration factor were more pronounced in shell than in soft parts. Significant relationships with clam size for Cd, Cr, Co and Zn followed inverse power functions. In contrast, the degree of Ag bioaccumulation was positively correlated with size. In view of the literature on Ag in bivalves, the latter observation suggests the occurrence of a specific detoxification mechanism (sequestration) that would be more efficient in old individuals. Overall, the experimental results indicate that the use of G. tumidum as a bioindicator in monitoring programmes requires selecting individuals of a specific size range in order to obtain comparable information about ambient metal levels. Since the size effect is greatest among smaller individuals, it is recommended to select clams with a shell width greater than 35 mm.