title: Delineation of ¹³⁴Cs uptake pathways (seawater and food) in the variegated scallop Mimachlamys varia.
abstract: Among bivalves, scallops have been shown to be good bioindicator species for radionuclide monitoring. The present paper looked at the Cs bioaccumulation capacities of the variegated scallop Mimachlamys varia exposed separately via seawater and food under laboratory conditions. Results were compared with data previously obtained for the king scallop Pecten maximus, the only Pectinid species for which Cs accumulation has been studied in laboratory. Results indicated that M. varia has higher uptake capacity (CF: 1.86 ± 0.08) but lower absorption efficiency (A0l: 33 ± 5%) than P. maximus when exposed to waterborne Cs (CF of P. maximus: 0.94 ± 0.05 and A0l: 45 ± 3%). When scallops were fed radiolabeled phytoplankton, the assimilation efficiency of Cs was similar for the two species (AE: 24 ± 3% for M. varia and 28 ± 4% for P. maximus). Interspecific differences in terms of accumulation and retention, can be explained by physiological factors (including size of individuals) and/or difference in storage mechanisms. Indeed, organotropism differed between the two scallop species, suggesting the occurrence of specific redistribution mechanisms towards the tissues involved in Cs storage, excretion and detoxification. Finally, the present study examined the relative contribution of the different exposure pathways (seawater and food) to global (134)Cs bioaccumulation for M. varia. Results showed that food constitutes the main accumulation pathway, contributing for 77% of the global (134)Cs bioaccumulation.
authors.affiliation: International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000 Principality of Monaco, Monaco; Littoral Environnement et Sociétés (LIENSs), UMR 7266, CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, F-17000 La Rochelle, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Pouil
authors.affiliation: Littoral Environnement et Sociétés (LIENSs), UMR 7266, CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, F-17000 La Rochelle, France.
authors.forename: Paco
authors.initials: P
authors.lastname: Bustamante
authors.affiliation: International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000 Principality of Monaco, Monaco.
authors.forename: Michel
authors.initials: M
authors.lastname: Warnau
authors.affiliation: International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000 Principality of Monaco, Monaco.
authors.forename: François
authors.initials: F
authors.lastname: Oberhänsli
authors.affiliation: International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000 Principality of Monaco, Monaco.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Teyssié
authors.affiliation: International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000 Principality of Monaco, Monaco. Electronic address: m.metian@iaea.org.
authors.forename: Marc
authors.initials: M
authors.lastname: Metian
mesh_terms: D000818:Animals; D002588:Cesium Radioisotopes / Q000378:metabolism*; D020387:Food Chain; D005602:France; D049897:Pectinidae / Q000378:metabolism*; D010839:Phytoplankton; D012623:Seawater / Q000032:analysis; D014875:Water Pollutants, Radioactive / Q000378:metabolism*
chemical_list: D002588:Cesium Radioisotopes; D014875:Water Pollutants, Radioactive
keywords: Bivalve; Cesium; Depuration; Kinetics; Scallop