|Sparling, Donald - USGS|
|Cowman, D - USGS|
|Fellers, G - USGS|
Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 11, 2001
Publication Date: N/A
Technical Abstract: Red-legged, foothill yellow-legged and mountain yellow-legged frog, Yosemite toads and western toads are showing alarming population declines in California, even in areas thought to be pristine. One potential cause of these declines is atmospheric transport of pesticide residues in the Central Valley of California and their subsequent dispersal into the Sierra Nevada foothills and mountains. Pacific treefrogs make good sentinel species for these other anurans because their tadpoles occupy similar habitats and they are numerous enough to sample. To document the extent of pesticide exposure, tadpole and adult Pacific treefrogs were collected from four transects running from the coast through the Central Valley into the mountains. These animals were analyzed for cholinesterase activity levels and their bodies, water and sediment were analyzed for insecticides.