Pesticides in amphibian habitats of Central and Northern California, USA

USDA
By: , and 

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Abstract

Previous studies have indicated that toxicity from pesticide exposure may be contributing to amphibian declines in California and that atmospheric deposition could be a primary pathway for pesticides to enter amphibian habitats. We report on a survey of California wetlands sampled along transects associated with Lassen Volcanic National Park, Lake Tahoe, Yosemite National Park, and Sequoia National Park. Each transect ran from the Pacific coast to the Cascades or Sierra Nevada mountains. Pacific chorus frogs (Pseudacris regilla), water, and sediment were collected from wetlands in 2001 and 2002. Twenty-three pesticides were found in frog, water, or sediment samples. Six contaminants including trifluralin, α-endosulfan, chlordanes, and trans-nonachlor were found in adult P. regilla. Seventeen contaminants were found in sediments, including endosulfan sulfate, chlordanes, 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene (4,4′-DDE), and chlorpyrifos. The mean number of chemicals detected per pond in sediments was 2.4 (2.5, standard deviation). In water, 17 chemicals were detected, with β-endosulfan being present in almost all samples. Trifluralin, chlordanes, and chlorpyrifos were the next most common. The mean number of chemicals in water per pond was 7.8 (2.9). With the possible exception of chlorpyrifos oxon in sediments and total endosulfans, none of the contaminants exceeded known lethal or sublethal concentrations in P. regilla tissue. Endosulfans, chlorpyrifos, and trifluralin were associated with historic and present day population status of amphibians. Cholinesterase, an essential neurological enzyme that can be depressed by certain pesticides, was reduced in tadpoles from areas with the greatest population declines.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Pesticides in amphibian habitats of Central and Northern California, USA
DOI 10.1021/bk-2013-1149
Volume 1149
Year Published 2013
Language English
Publisher ACS Publications
Contributing office(s) Western Ecological Research Center
Description 28 p.
Larger Work Title Occurrence, fate and impact of atmospheric pollutants on environmental and human health
First page 123
Last page 150
Online Only (Y/N) N
Additional Online Files (Y/N) N