SS4.03 Factors Controlling the Bioavailability and Bioaccumulation of Inorganic and Organic Chemicals into Aquatic Food Chains
Date: Friday, June 14, 2002
Time: 11:15:00 AM
Location: Carson B
BarranguetC, University of Amsterdam, Amsterdam, Netherlands,
van den Ende, F, , University of Amsterdam, Amsterdam, Netherlands,
Rutgers, M, , RIVM, Bilthoven, Netherlands,
Breure, A, , RIVM, Bilthoven, Netherlands,
Greijdanus, M, , RIZA, Lelystad, Netherlands,
Sinke, J, J, NIOO-Cemo, Yerseke, Netherlands,
Admiraal, W, , University of Amsterdam, Amsterdam, Netherlands,
Modifications in the trophic relations of auto-heterotrophic biofilms exposed to Cu.
The effects of copper (Cu) on photosynthetic riverine biofilms were studied in artificial stream channels. Direct effects on the composition and functioning of the biofilms were examined using plant pigments, CLPP and PAM-fluorescence. Cu affected directly the autotrophic and heterotrophic microbial biofilm communities, as well as their grazers. Grazing by snails, which appeared to be an important factor structuring biofilms without any Cu addition, had a minor effect on Cu exposed biofilms. Although grazing changed the bacterial composition, its effects were not detected either on the algal community or on the biofilm tolerance to Cu. Cu caused a significant reduction of microalgal biomass and induced a shift from diatoms to cyanobacteria. However, the replacement of species was not totally effective to overcome the toxic effects of Cu. A direct effect of Cu could also be shown in the bacterial community and changes in the CLPP could be related to the Cu treatment. The change of the biofilm microbial composition points to the indirect Cu effects on biofilms, due to the close interdependence of biofilm autotrophic and heterotrophic compartments.