The toxicity of several agricultural chemicals to aquatic invertebrates has been shown to be temperature-dependent, but the role of daily temperature variation has rarely been examined. The authors simulated a natural daily temperature pattern (a fluctuating cycle of 21 °C to 31 °C over a 24-h period) based on field-collected data from Southern High Plains wetlands (TX, USA) and conducted a series of experiments comparing responses from this exposure scenario to a constant exposure at 24 ± 1 °C. Results indicate alterations in pesticide toxicity under the fluctuating temperature regime compared with that of the constant temperature exposure. There was a significant interaction of temperature regime and bifenthrin on Chironomus dilutus survival, and C. dilutus ash-free dry mass was lower in the fluctuating temperature treatment. The 10-d median lethal concentration (LC50) for Hyalella azteca exposed to chlorothalonil was lower under the fluctuating temperature regime compared with the constant temperature regime. For Daphnia magna exposed to malathion, the main effects of temperature regime and malathion were observed on cholinesterase activity. The present study demonstrates how environmentally relevant daily temperature variation influences contaminant effects on aquatic invertebrates. Environ Toxicol Chem 2013;32:2738–2745. © 2013 SETAC
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.