Hédouin Laetitia auteur aut IRD Pringault Olivier auteur aut IRD Metian M. auteur aut IRD Bustamante P. auteur aut IRD Warnau M. auteur aut IRD text journalArticle eng text/pdf born digital access The New Caledonian lagoon is submitted to intense heavy metal input from land-based Ni mining. Therefore, the use of sentinel species is strongly recommended in order to develop and implement coastal zone management programmes of the metal contamination. The tropical oysters Isognomon isognomon and Malleus regula and the clam Gafrarium tumidum were previously proposed as such possible sentinel organisms and were thus investigated in this context. The three species were exposed to Ni via seawater or food using radiotracer techniques. Results indicate that uptake and retention efficiencies of Ni are independent of the dissolved Ni concentrations in the surrounding seawater. Hence, for the three species, body concentrations of Ni taken up from the dissolved phase are directly proportional to the ambient dissolved concentrations. Biokinetic patterns indicated that the major part of Ni was rapidly lost from bivalves during the first days of depuration, whereas 7 to 47% of Ni-63 were retained in tissues with a biological half-life not significantly different from infinity. Finally, feeding experiments showed that Ni ingested with food (phytoplankton) was assimilated more efficiently in clams (assimilation efficiency, AE = 61%) than in oysters (AE = 17%), and was strongly retained (T-b1/2 >= 35 d) in the tissues of both bivalves. It is concluded that the investigated species examined are efficient bioaccumulators of Ni from both the surrounding seawater and the food, and that they would be useful bioindicators for monitoring the status of Ni contamination in tropical coastal waters. specialized metal molluscs mining activities bioindicator radiotracer 082 66 8 1449-1457 2007 0045-6535 https://www.documentation.ird.fr/hor/fdi:010037826 10.1016/j.chemosphere.2006.09.015 0045-6535 [F B010037826] https://www.documentation.ird.fr/hor/fdi:010037826 https://www.documentation.ird.fr/intranet/publi/2007/03/010037826.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2007-03-30 2017-08-23 fdi:010037826 fre