title: Response of macroinvertebrate communities to temporal dynamics of pesticide mixtures: A case study from the Sacramento River watershed, California.
abstract: Pesticide pollution from agricultural field run-off or spray drift has been documented to impact river ecosystems worldwide. However, there is limited data on short- and long-term effects of repeated pulses of pesticide mixtures on biotic assemblages in natural systems. We used reported pesticide application data as input to a hydrological fate and transport model (Soil and Water Assessment Tool) to simulate spatiotemporal dynamics of pesticides mixtures in streams on a daily time-step. We then applied regression models to explore the relationship between macroinvertebrate communities and pesticide dynamics in the Sacramento River watershed of California during 2002-2013. We found that both maximum and average pesticide toxic units were important in determining impacts on macroinvertebrates, and that the compositions of macroinvertebrates trended toward taxa having higher resilience and resistance to pesticide exposure, based on the Species at Risk pesticide (SPEARpesticides) index. Results indicate that risk-assessment efforts can be improved by considering both short- and long-term effects of pesticide mixtures on macroinvertebrate community composition.
authors.affiliation: Department of Environmental Science, Policy & Management, University of California at Berkeley, Berkeley, 94720 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 at Berkeley, Berkeley, 94720 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 at Berkeley, Berkeley, 94720 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; D017753:Ecosystem; D004784:Environmental Monitoring; D007448:Invertebrates / Q000145:classification / Q000187:drug effects*; D010575:Pesticides / Q000009:adverse effects* / Q000032:analysis; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000032:analysis
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Aquatic toxicity; Macroinvertebrate communities; Pesticides; SPEAR index; Streams