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Bioturbation effects on cadmium and zinc transfers from a contaminated sediment and on metal bioavailability to benthic bivalves
Author(s) -
Ciutat Aurélie,
Boudou Alain
Publication year - 2003
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620220721
Subject(s) - bioturbation , cadmium , water column , microcosm , sediment , benthic zone , environmental chemistry , zinc , bioavailability , corbicula fluminea , chemistry , environmental science , ecology , biology , paleontology , bioinformatics , organic chemistry
Abstract The two main objectives of this study were to compare cadmium and zinc fluxes from a contaminated sediment to the water column in bioturbated and unbioturbated systems and jointly to analyze accumulation kinetics of these released metals by benthic filter‐feeder bivalves. The experimental approach was based on indoor microcosms containing a two‐compartment biotope: natural contaminated sediment (45 ± 5 μg Cd/g, dry wt, and 1,938 ± 56 μg Zn/g, dry wt) and water column. Four experimental conditions were studied: no organism added to the sediment‐water biotope, presence of bivalves Corbicula fluminea , presence of Hexagenia rigida nymphs (bioturbation source), and presence of C. fluminea and H. rigida simultaneously. Results reveal that bioturbation produces a significant metal release into the water column via the resuspended sediment particles. The use of C. fluminea as an indicator of transferred metals in the water column shows that the metal bioavailability is very limited, quantities of cadmium and zinc bioaccumulated in the soft bodies being less than those measured in unbioturbated systems. This experimental study demonstrates that only the dissolved fraction resulting from diffusive metal fluxes across the sediment‐water interface is bioavailable for this bivalve species.