Inhaltszusammenfassung

Episodic pollution events such as runoff or spraydrift can lead to a short-term (few hours) contamination of aquatic ecosystems with pesticides. So far, different short-term exposures with respect to long-term effects have not been studied, In the present study, caddisfly larvae, typical for agricultural streams (Limnephilus lunatus Curtis, 2nd and 3rd instar) were exposed for 1- vs 10-h to three different equivalent doses (mu g h) of fenvalerate. After transfer into an artificial stream micr...Episodic pollution events such as runoff or spraydrift can lead to a short-term (few hours) contamination of aquatic ecosystems with pesticides. So far, different short-term exposures with respect to long-term effects have not been studied, In the present study, caddisfly larvae, typical for agricultural streams (Limnephilus lunatus Curtis, 2nd and 3rd instar) were exposed for 1- vs 10-h to three different equivalent doses (mu g h) of fenvalerate. After transfer into an artificial stream microcosm with pesticide-free water, chronic effects were observed over 240 days. Comparison of 1- and 10-h exposure revealed that l-h contamination leads to stronger effects. The differences were significant for the sublethal endpoints emergence pattern and dry weight of adults (ANOVA, Fisher's PLSD; P < 0.05). In terms of exposure dose, the difference between 1- and 10-h exposure equals a factor of 6 as a mean of all endpoints studied. The following significant effect levels for the l-h exposure were obtained for the different endpoints investigated: reduced emergence success and production at 0.1 mu g l(-1), temporal pattern of emergence at 0.001 mu g l(-1), dry weight of adults at 0.01 mu g l(-1) (C) 2000 Elsevier Science Ltd. All rights reserved. » weiterlesen» einklappen

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