title: Chemical cocktails in aquatic systems: pesticide effects on the response and recovery of >20 animal taxa.
abstract: Natural systems are often exposed to individual insecticides or combinations of multiple insecticides. Using an additive and substitutive design, we examined how populations and communities containing >20 animal taxa are affected by four insecticides applied individually and as a mixture for 18 wks in aquatic mesocosms. The four insecticides had distinct lethal effects on the response and recovery of cladocerans, copepods, amphipods, isopods, and amphibians but not snails. The lethal effect on cladocerans and copepods induced trophic cascades that facilitated algal blooms and abiotic changes (higher pH and dissolved oxygen, but lower light transmission). Exposure to endosulfan resulted in a lag effect reducing cladocerans and spring-breeding amphibian abundance. The reduction in spring-breeding amphibian abundance led to cascading indirect effects on summer-breeding amphibians. Finally, the mixture treatment had lethal effects throughout the community that led to long-term effects on amphibian mass and unique indirect consequences on phytoplankton and abiotic variables.
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, 101 Clapp Hall, Pittsburgh, PA 15260, USA. Electronic address: jhua13@gmail.com.
authors.forename: Jessica
authors.initials: J
authors.lastname: Hua
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, 101 Clapp Hall, Pittsburgh, PA 15260, USA.
authors.forename: Rick
authors.initials: R
authors.lastname: Relyea
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects*; D017753:Ecosystem; D020387:Food Chain; D010575:Pesticides / Q000633:toxicity; D012098:Reproduction / Q000187:drug effects; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Aquatic community; Insecticide mixtures; Organochlorine; Organophosphate