||Experimental Ponds for Evaluating Bioassay Predictions.
deNoyelles, F. ;
Kettle, W. D. ;
||Kansas Univ., Lawrence.;Corvallis Environmental Research Lab., OR.
Chlorine organic compounds ;
Nitrogen heterocyclic compounds ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
Experimental pond studies were used to demonstrate a means of assessing the accuracy of laboratory and in situ bioassays predicting the effects of chemical stress on phytoplankton. A short-term batch bioassay using changing carbon uptake in photosynthesis predicted an immediate (first 24h) effect of the herbicide atrazine on the phytoplankton communities in experimental ponds. After addition of atrazine to the ponds, the same decreases in carbon uptake were observed, but the appearance of resistant species that soon occurred could not be predicted with the short-term exposure used in such a bioassay. From another experimental pond study a longer-term continuous flow bioassay using changing species composition predicted an effect of increased nutrient and altered pH conditions over a 20-day exposure.