Cadmium effects in food chain experiments with marine plankton algae (Dinophyta) and benthic filter feeders (Tunicata)
Kayser, H. (1982). Cadmium effects in food chain experiments with marine plankton algae (Dinophyta) and benthic filter feeders (Tunicata). Neth. J. Sea Res. 16: 444-454
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Abstract |
The dinoflagellate Scrippsiella faeroense was grown in continuous flow- through cultures (10 l turbidostats), the outflow leading into vessels containing tunicates of the species Ciona intestinalis, Ascidiella aspersa, Molgula manhaltensis and Botryllus schlosseri. The culture medium consisted of natural sea water enriched only with N and P components. CdCl2 was added to the system at sublethal concentrations. Algal growth was affected at a Cd++ concentration of 10 ug.l -1;sublethal toxicity thresholds of the tunicates ranged from 5 to 10 ug.l-1. Cad mium accumulation was much higer in the algae than in the tunicates; in spite of the continuous supply of relatively highly Cd contaminated algae, the Cd content of algae-fed tunicates increased insignificantly by comparison with unfed specimens. Only a small percentage of the Cd offered via the food algae was actually assimilated by the ascidians during the first 3 weeks of the experiment. Cd content of the tunicates remained almost constant for the next 2 weeks of the experiment, indicating that ingestion and excretion of the metal was at equilibrium. The concentration factor of Cd decreased through the trophic chain. |
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