Common insecticide disrupts aquatic communities: A mesocosm-to-field ecological risk assessment of fipronil and its degradates in U.S. streams

Janet L. Miller; Travis S. Schmidt; Peter C. Van Metre; Barbara Mahler; Mark W. Sandstrom; Lisa H. Nowell; Daren M. Carlisle; Patrick W. Moran

doi:10.1126/sciadv.abc1299

USGS · 70241571

Common insecticide disrupts aquatic communities: A mesocosm-to-field ecological risk assessment of fipronil and its degradates in U.S. streams

Janet L. Miller·Travis S. Schmidt·Peter C. Van Metre·Barbara Mahler·Mark W. Sandstrom·Lisa H. Nowell·Daren M. Carlisle·Patrick W. Moran

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Abstract

Insecticides in streams are increasingly a global concern, yet information on safe concentrations for aquatic ecosystems is sparse. In a 30-day mesocosm experiment exposing native benthic aquatic invertebrates to the common insecticide fipronil and four degradates, fipronil compounds caused altered emergence and trophic cascades. Effect concentrations eliciting a 50% response (EC 50 ) were developed for fipronil and its sulfide, sulfone, and desulfinyl degradates; taxa were insensitive to fipronil amide. Hazard concentrations for 5% of affected species derived from up to 15 mesocosm EC 50 values were used to convert fipronil compound concentrations in field samples to the sum of toxic units (∑TU Fipronils ). Mean ∑TU Fipronils exceeded 1 (indicating toxicity) in 16% of streams sampled from five regional studies. The Species at Risk invertebrate metric was negatively associated with ∑TU Fipronils in four of five regions sampled. This ecological risk assessment indicates that low concentrations of fipronil compounds degrade stream communities in multiple regions of the United States.

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Janet L. Miller, Travis S. Schmidt, Peter C. Van Metre, Barbara Mahler, Mark W. Sandstrom, Lisa H. Nowell, Daren M. Carlisle, Patrick W. Moran. 2020. Common insecticide disrupts aquatic communities: A mesocosm-to-field ecological risk assessment of fipronil and its degradates in U.S. streams. https://doi.org/10.1126/sciadv.abc1299

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