Biomonitoring of estrogenic exposure and identification of responsible compounds in bream from Dutch surface waters.

The exposure to and effects of estrogenic compounds in male breams from Dutch freshwater locations were investigated. Ovotestis was observed infrequently (maximum frequency 16%). However, plasma vitellogenin (VTG) concentration was elevated highly at some locations.

Effects of copper and temperature on aquatic bacterial communities.

The present study aimed to characterise effects of copper and temperature on bacterial communities in photosynthetic biofilms using a suit of supplementary methods: pollution-induced community tolerance (PICT), DNA profiles with denaturing gradient gel electrophoresis (DGGE) and physiological profiles with community-level physiological profiling (CLPP). Biofilms of algae and bacteria were grown in a ditch of a Dutch polder and exposed in the laboratory to copper (3 microM and a reference) at three different temperatures (10, 14 and 20 degrees C). Bacterial communities sampled from the field showed heterogeneity in their physiological profiles, however the heterogeneity decreased during laboratory incubation.

Copper-induced modifications of the trophic relations in riverine algal-bacterial biofilms.

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 investigated using plant pigments, community-level physiological profiles (CLPP), and pulse-amplitude-modulated (PAM) fluorescence. Copper caused a significant reduction of microalgal biomass and induced a shift in the population from diatoms to cyanobacteria.