Admiraal, W. W. University of Amsterdam/ARISE, admiraal@bio.uva.nl
Barranguet, C. W. University of Amsterdam/ARISE, barranguet@bio.uva.nl
Ivorra, N. N. University of Amsterdam/ARISE, castella@bio.uva.nl
Plans, M. M. University of Barcelona,

 
INTERACTIONS OF MICRO-BENTHIC COMMUNITIES WITH DISSOLVED METALS IN RIVER WATER
 
Biofilm communities in rivers are greatly stimulated by microalgal growth on solid substrates and shallow sediments. Mucus production and daily pH and oxygen regimes caused by algal activity are supposed to be vital to a variety of processes such as the binding of particulate matter, the stimulation of bacterial activity, and the precipitation of metals. These interactions were analysed using metal concentrations in water and biofilm measured concurrently with microphyte density, production, and bacterial activity. A comparative study on ca. 15 European rivers showed that partitioning of metals between water and biofilm shows a large variability among river sites. In agreement, experiments with hard substrate periphytic communities in the R. Meuse showed that Zn and Cd are rapidly precipitated in well developed metal tolerant algal communities. In contrast, Cu partitioning followed an equilibrium model in experiments. The inhibition of photosynthetic activity of biofilm algae (recorded with Pulse Amplitude Modulation, PAM) and bacteria (recorded by 3H thymidine incorporation and esterase activity) to external metal concentrations is compared to the sorption behaviour of metals. Transport and binding in the biofilm is discussed in relation to purification of the water and detoxification in the biofilm.
 
Day: Monday, Feb. 1
Time: 04:00 - 04:15pm
Location: Hilton of Santa Fe
 
Code: SS06MO0400H