title: Climate-change influences on the response of macroinvertebrate communities to pesticide contamination in the Sacramento River, California watershed.
abstract: Limited studies have addressed how future climate-change scenarios may alter the effects of pesticides on biotic assemblages or the effects of exposures to repeated pulses of pesticide mixtures. We used reported pesticide-use data as input to a hydrological fate and transport model (Soil and Water Assessment Tool) under multiple climate-change scenarios to simulate spatiotemporal dynamics of pesticides mixtures in streams on a daily time-step in the Sacramento River watershed of California. We predicted that there will be increased pesticide application with warming across the watershed, especially in upstream areas. Using a statistical model describing the relationship between macroinvertebrate communities and pesticide dynamics, we found that compared to the baseline period of 1970-1999: (1) most climate-change scenarios predicted increased rainfall and warming across the watershed during 2070-2099; and (2) increasing pesticide contamination and increased impact on macroinvertebrates will likely occur in most areas of the watershed by 2070-2099; and (3) lower increases in effects of pesticides on macroinvertebrates were predicted for the downstream areas with intensive agriculture compared to some upstream areas with less-intensive agriculture. Future efforts on practical adaptation and mitigation strategies can be improved by awareness of altered threats of pesticide mixtures under future climate-change conditions.
authors.affiliation: Department of Environmental Science, Policy & Management, University of California, Berkeley, 94720-3114, CA, USA. Electronic address: mcchiu@berkeley.edu.
authors.forename: Ming-Chih
authors.initials: MC
authors.lastname: Chiu
authors.affiliation: Department of Environmental Science, Policy & Management, University of California, Berkeley, 94720-3114, CA, USA. Electronic address: lisahunt@berkeley.edu.
authors.forename: Lisa
authors.initials: L
authors.lastname: Hunt
authors.affiliation: Department of Environmental Science, Policy & Management, University of California, Berkeley, 94720-3114, CA, USA. Electronic address: resh@berkeley.edu.
authors.forename: Vincent H
authors.initials: VH
authors.lastname: Resh
mesh_terms: D000383:Agriculture; D000818:Animals; D002140:California; D057231:Climate Change; D004784:Environmental Monitoring; D007448:Invertebrates; D010575:Pesticides / Q000032:analysis*; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Aquatic ecotoxicity; Benthic macroinvertebrates; Precipitation; Sediment; Warming