Amphipoda

Ecology

Neuroscience

Gammarus pulex

Biology

Pesticide

Toxicant

Computer science

Multiple exposure

Computer network

Organic chemistry

Ecotoxicology

Toxicity

STREAMS

Toxicology

Environmental chemistry

Contamination

Environmental science

Ecotoxicity

Pesticide residue

Chemistry

Crustacean

Stressor

Computer vision

The Science of The Total Environment

Frequent pesticide-related impacts on ecosystems at concentrations considered environmentally safe indicate that the current risk assessment framework for registration of pesticides is not protective enough. Causes may include difficulties in assessing the effects of sequential pesticide pulses and their interaction with environmental stressors. By contrast to such realistic scenarios, risk assessment for registration of pesticides is typically based on tests of a single exposure period under benign laboratory conditions. Here, we investigated the toxicological sensitivity of Gammarus pulex, an ecologically relevant crustacean, from uncontaminated control streams and pesticide-contaminated agricultural streams by exposing them to pesticide contamination in the laboratory. Individuals from contaminated streams were 2.7-fold more sensitive to pesticide exposure than individuals from the reference streams. We revealed that this increase in sensitivity was the result of a synergistic interaction of sequential pesticide exposure and temperature stress. Such multiple stressor scenarios are typical for agricultural streams. We conclude that the interactive effects of sequential toxicant exposure and additional environmental stressors need to be considered in a realistic risk assessment framework.

Sequential exposure to low levels of pesticides and temperature stress increase toxicological sensitivity of crustaceans