Éditeur(s) : Elsevier
Résumé : The uptake and loss kinetics of Cd were determined in two species of scallops from the European coasts, the variegated scallop Chlamys varia and the king scallop Pecten maximus, following exposures via seawater, phytoplankton and sediment using highly sensitive radiotracer techniques (Cd-109). Results indicate that, for seawater and dietary pathways, C. varia displays higher bioaccumulation capacities in terms of uptake rate from water and fraction absorbed from ingested food (assimilation efficiency) than Pecten maximus. Regarding sediment exposure, P. maximus displayed low steady-state Cd transfer factor (TFSS < 1); however, once incorporated, a very large part of Cd transferred from sediment (92%) was strongly retained within R maximus tissues. Both species showed a high retention capacity for Cd (biological half-life, T-b1/2 > 4 months), suggesting efficient mechanisms of detoxification and storage in both species. The digestive gland was found to be the main storage organ of Cd in the two scallops regardless of the exposure pathway. However, Cd was stored differently within this organ according to the species considered: 40% of the total Cd was found in the soluble cellular fraction in C. varia whereas this soluble fraction reached 80% for P. maximus. This suggests that the two species displayed different Cd detoxification/storage mechanisms. Finally, the present study has determined the relative contribution of the different exposure pathways to global Cd bioaccumulation for the two scallop species. Results clearly show that for both species, food constitutes the major accumulation pathway, contributing for >99% and 84% of the global Cd bioaccumulation in C. varia and R maximus, respectively. This work confirms the previous assumption, derived from a bibliographic overview, that dietary pathway plays a prevalent role in metal bioaccumulation in Pectinidae. (C) 2007 Elsevier B.V. All rights reserved.
Journal of Experimental Marine Biology and Ecology (0022-0981) (Elsevier), 2007-12 , Vol. 353 , N. 1 , P. 58-67

Droits : 2007 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-3581.pdf
DOI:10.1016/j.jembe.2007.09.001
http://archimer.ifremer.fr/doc/00000/3581/

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : The present work aimed at better understanding metal and metalloid bioaccumulation in the edible Pacific blue shrimp Litopenaeus stylirostris, using both laboratory and field approaches. In the laboratory, the bioaccumulation kinetics of Ag, Cd, Co, Cr, and Zn have been investigated in shrimp exposed via seawater and food, using the corresponding gamma-emitting radiotracers (Ag-110m, Cd-109, Co-57, Cr-51, and Zn-65) and highly sensitive nuclear detection techniques. Results showed that hepatopancreas and intestine concentrated the metals to the highest extent among the blue shrimp organs and tissues. Moulting was found to play a non negligible detoxification role for Co, Cr and, to a lesser extent, Zn. Metal retention by L stylirostris widely varied (from a few days to several months), according to the element and exposure pathway considered (a given metal was usually less strongly retained when ingested with food than when it was taken up from the dissolved phase). In the field study, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, and Zn were analysed in shrimp collected from a New Caledonian aquaculture pond. Metal concentrations in the shrimp muscles were generally relatively low and results confirmed the role played by the digestive organs and tissues in the bioaccumulation/storage/detoxification of metals in the Pacific blue shrimp. Preliminary risk considerations indicate that consumption of the shrimp farmed in New Caledonia is not of particular concern for human health. (C) 2010 Elsevier Ltd. All rights reserved.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2010 , Vol. 61 , N. 7-12 , P. 576-584

Droits : 2010 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00014/12528/9869.pdf
DOI:10.1016/j.marpolbul.2010.06.035
http://archimer.ifremer.fr/doc/00014/12528/

Éditeur(s) : Elsevier
Résumé : Uptake of waterborne Cd, Co, Mn and Zn was determined in laboratory experiments using radiotracer techniques (Cd-109, Co-57, Mn-54 and Zn-65). Labelled Zn was mainly accumulated in the digestive gland (65%) and Co in kidneys (81%); Cd and Mn were similarly distributed in digestive gland and gills. In a complementary field study, Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, and Zn were analysed in scallops collected at two stations showing different contamination levels. Digestive gland and kidneys displayed the highest concentrations. Ag, As, Cd, and Fe differed in soft tissues from the two stations, suggesting that Comptopallium radula could be a valuable local biomonitor species for these elements. Low Mn and Zn concentrations found in kidneys suggest that their content in calcium-phosphate concretions differs from the other pectinids. Preliminary risk considerations suggest that As would be the only element potentially leading to exposure of concern for seafood consumers. (c) 2007 Elsevier Ltd. All rights reserved.
Environmental Pollution (0269-7491) (Elsevier), 2008-04 , Vol. 152 , N. 3 , P. 543-552

Droits : 2007 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-6953.pdf
DOI:10.1016/j.envpol.2007.07.009
http://archimer.ifremer.fr/doc/00000/6953/