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Ecological consequences of neonicotinoid mixtures in streams

April 13, 2022
Neonicotinoid mixtures are common in streams worldwide, but corresponding ecological responses are poorly understood. We combined experimental and observational studies to narrow this knowledge gap. The mesocosm experiment determined that concentrations of the neonicotinoids imidacloprid and clothianidin (range of exposures, 0 to 11.9 μg/liter) above the hazard concentration for 5% of species (0.017 and 0.010 μg/liter, respectively) caused a loss in taxa abundance and richness, disrupted adult emergence, and altered trophodynamics, while mixtures of the two neonicotinoids caused dose-dependent synergistic effects. In 85 Coastal California streams, neonicotinoids were commonly detected [59% of samples (n = 340), 72% of streams], frequently occurred as mixtures (56% of streams), and potential toxicity was dominated by imidacloprid (maximum = 1.92 μg/liter) and clothianidin (maximum = 2.51 μg/liter). Ecological responses in the field were consistent with the synergistic effects observed in the mesocosm experiment, indicating that neonicotinoid mixtures pose greater than expected risks to stream health.

Citation Information

Publication Year 2022
Title Ecological consequences of neonicotinoid mixtures in streams
DOI 10.1126/sciadv.abj8182
Authors Travis S. Schmidt, Janet L. Miller, Barbara Mahler, Peter C. Van Metre, Lisa H. Nowell, Mark W. Sandstrom, Daren Carlisle, Patrick W. Moran, Paul Bradley
Publication Type Article
Publication Subtype Journal Article
Series Title Science Advances
Index ID 70230500
Record Source USGS Publications Warehouse
USGS Organization WY-MT Water Science Center