Availability of copper from phytoplankton and water for the bivalveMacoma balthica. II. Uptake and elimination from64Cu-labelled diatoms and water

Abstract

Abstract. The amount of copper taken up via algae and water by Macoma balthica from the Oosterschelde sea arm, S.W. Netherlands, was established using the radioisotope 64Cu. As far as we know, this isotope has never been used before in marine food chain studies. As a model food source the marine diatom Phaeodactylum tricornutum was allowed to accumulate 64Cu for 1 d.These labelled algae were fed to the clams in the presence of the complexing agent EDTA (0.27 raM). EDTA was added to prevent uptake of dissolved 64Cu that could be leaking from the labelled diatoms. In control experiments, unlabelled diatoms were fed to M. balthica in the presence of dissolved 64Cu (with and without EDTA) in order to assure a similar filtration activity. In repeated experiments with varying particulate/dissolved copper ratios, uptake through food always turned out to be at least as efficient as uptake from the water. It was concluded that Cu, associated with food, is well available for uptake by M. balthica.

Concentrations of Selected Heavy Metals in Benthic Diatoms and Sediment in the Westerschelde Estuary

“…On the other hand, for deposit feeding bivalves like Macoma balthica, food might contribute to a large extent to the overall metal uptake (Absil et al 1994). This is likely, because filtration rates are much lower; deposit feeders select from a concentrated source, whereas suspension feeders have to concentrate a very dilute source (Gilbert 1977) and are therefore likely to accumulate more metals through the dissolved phase.…”

Assimilation of trace elements and carbon by the mussel Mytilus edulis: Effects of food composition

“…Metal AEs should be tested rigorously in this bioindicator species and bioaccumulation models should be validated by comparing model predictions of metal concentrations in animals with metal concentrations in field-collected animals. Relatively few studies have measured metal assimilation in bivalves (Decho and Luoma 199 1;Absil et al 1994;Wang et al 1995), and the factors that control it are not well known. We used radiotracer techniques to determine the influence of food quality on metal assimilation by marine mussels (M. edulis).…”

Monitoring of the aquatic environment by species accumulator of pollutants: a review

“…Absil et al (1994a;1994b) carried out accurate experiments to evaluate the percentage of copper incorporated by the bivalve Macoma balthica from its food, consisting of the diatom Phaeodactylum tricornutum labelled with 64 Cu. Because the biological availability of metal complexed by chelators is very small, EDTA was added to the water to minimise the uptake by the mollusc of dissolved 64 Cu leaked from the labelled diatoms.…”