title: Effect of Simultaneous Amphibian Exposure to Pesticides and an Emerging Fungal Pathogen, Batrachochytrium dendrobatidis.
abstract: Amphibian declines have been linked to numerous factors, including pesticide use and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Moreover, research has suggested a link between amphibian sensitivity to Bd and pesticide exposure. We simultaneously exposed postmetamorphic American toads (Anaxyrus americanus), western toads (A. boreas), spring peepers (Pseudacris crucifer), Pacific treefrogs (P. regilla), leopard frogs (Lithobates pipiens), and Cascades frogs (Rana cascadae) to a factorial combination of two pathogen treatments (Bd+, Bd-) and four pesticide treatments (control, ethanol vehicle, herbicide mixture, and insecticide mixture) for 14 d to quantify survival and infection load. We found no interactive effects of pesticides and Bd on anuran survival and no effects of pesticides on infection load. Mortality following Bd exposure increased in spring peepers and American toads and was dependent upon snout-vent length in western toads, American toads, and Pacific treefrogs. Previous studies reported effects of early sublethal pesticide exposure on amphibian Bd sensitivity and infection load at later life stages, but we found simultaneous exposure to sublethal pesticide concentrations and Bd had no such effect on postmetamorphic juvenile anurans. Future research investigating complex interactions between pesticides and Bd should employ a variety of pesticide formulations and Bd strains and follow the effects of exposure throughout ontogeny.
authors.affiliation: Department of Biological Sciences, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
authors.forename: Devin K
authors.initials: DK
authors.lastname: Jones
authors.forename: Trang D
authors.initials: TD
authors.lastname: Dang
authors.forename: Jenny
authors.initials: J
authors.lastname: Urbina
authors.affiliation: Department of Biological Sciences, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Bendis
authors.affiliation: Marine Science Institute, University of California Santa Barbara , Santa Barbara, California 93106, United States.
authors.forename: Julia C
authors.initials: JC
authors.lastname: Buck
authors.affiliation: Department of Biological Sciences, Southwestern Oklahoma State University , Weatherford, Oklahoma 73096, United States.
authors.forename: Rickey D
authors.initials: RD
authors.lastname: Cothran
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Blaustein
authors.affiliation: Department of Biological Sciences, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
authors.forename: Rick A
authors.initials: RA
authors.lastname: Relyea
mesh_terms: D000818:Animals; D001001:Anura; D002025:Bufonidae; D008411:Chytridiomycota; D054884:Host-Pathogen Interactions; D010575:Pesticides
chemical_list: D010575:Pesticides