title: Rare earth element distributions and fractionation in plankton from the northwestern Mediterranean Sea.
abstract: Rare earth element (REE) concentrations were measured for the first time in plankton from the northwestern Mediterranean Sea. The REE concentrations in phytoplankton (60-200 μm) were 5-15 times higher than those in four size fractions of zooplankton: 200-500 μm, 500-1000 μm, 1000-2000 μm and >2000 μm. The concentrations within these zooplankton fractions exhibited the same ranges with some variation attributed to differences in zooplankton taxonomy. The REE concentrations in plankton were poorly related to the reported REE concentrations of seawater, but they correlated well with the calculated REE(3+), concentrations especially with regard to middle REE (MREEs) and heavy REEs (HREEs). Plankton and seawater revealed different PAAS-normalised REE distributions, with the greatest differences observed in the light REEs. Interestingly, a comparison of PAAS-normalized sediment particles from the study of Fowler et al. (1992) showed concentrations of the same order of magnitude and a similar REE distribution without MREE enrichment. Based on this comparison, we propose a conceptual model that emphasizes the importance of biological scavenging of REEs (especially LREEs) in surface waters.
authors: Seoul National University, School of Earth and Environmental Sciences/RIO, Seoul National University, Seoul 151-747, Republic of Korea; Laboratoire d'étude des Transferts en Hydrologie et Environnement LTHE-IRD, UMR 5564, Domaine Universitaire, 38041 Grenoble Cedex 09, France. Electronic address: emilie.strady@ujf-grenoble.fr.
authors: Emilie
authors: E
authors: Strady
authors: Seoul National University, School of Earth and Environmental Sciences/RIO, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Intae
authors: I
authors: Kim
authors: Aix Marseille University, CNRS, CEREGE UMR 7330, F-13545 Aix En Provence, France.
authors: Olivier
authors: O
authors: Radakovitch
authors: Seoul National University, School of Earth and Environmental Sciences/RIO, Seoul National University, Seoul 151-747, Republic of Korea.
authors: Guebuem
authors: G
authors: Kim
mesh_terms: D000818:Animals; D005591:Chemical Fractionation; D033361:Cladocera / Q000737:chemistry; D033342:Copepoda / Q000737:chemistry; D004784:Environmental Monitoring; D049851:Gastropoda / Q000737:chemistry; D008522:Mediterranean Sea; D008674:Metals, Rare Earth / Q000032:analysis*; D010839:Phytoplankton / Q000737:chemistry*; D012623:Seawater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015048:Zooplankton / Q000737:chemistry*
chemical_list: D008674:Metals, Rare Earth; D014874:Water Pollutants, Chemical
keywords: Fractionation; Mediterranean Sea; Phytoplankton; Rare earth elements; Zooplankton