GEOC 12 |
| François L.L. Muller, Department of Chemistry, University of Bergen, Allegaten 41, 5007 Bergen, Norway and Aud Larsen, Department of Microbiology, University of Bergen, Jahnebakken 5, 5020 Bergen, Norway. |
| Trace metal speciation in surface coastal waters depends to a large extent on the effects of biologically mediated processes operating on a time scale of hours to days. A mesocosm experiment conducted in a fjordic environment in August 2002 revealed a tight interdependence between electrochemically labile manganese and heterotrophic bacterial abundance. The degree of lability of copper was controlled through active release of high-affinity organic ligands (log K1'=15.6; log K2'=13.2) by the marine cyanobacterium Synechococcus, while zinc-binding ligands (log K'=8.6) appeared to be derived from the break-up, bacterial decomposition or viral lysis of algal cells. Together, these processes imparted characteristic and reproducible variations on the concentrations of labile manganese, copper and zinc over the 21-day duration of the experiment. The extent to which such variations may, in turn, influence algal/bacterial community structure will be discussed. |
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Chemistry of Metals in Terrestrial and Aquatic Systems
1:25 PM-5:05 PM, Sunday, March 28, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |