Frogs from the country and mountain's of California were found to be contaminated with pesticides from the valley.
Pesticides like triazines, endosulfan and organophosphates are used in the valley area, which produces more than eight percent of U.S. "agricultural output value," a Wiley press release reported. California also comes in as number one for most pesticide use in the country.
"Our results show that current-use pesticides, particularly fungicides, are accumulating in the bodies of Pacific chorus frogs in the Sierra Nevada," Kelly Smalling a research hydrologist from the U.S. Geological Survey, said. "This is the first time we've detected many of these compounds, including fungicides, in these remote locations."
Researchers took samples from seven sites in Yosemite Park, Lake Tahoe, Giant Sequoia National Monument, and others. They tested water and sediment around the areas, as well as some resident frogs, for over 90 types of pesticides, a U.S. geological survey press release reported.
The team found the fungicides pyraclostrobin and tebuconazol in the frog's tissue most frequently, along with one herbicide, simazine. This was the first time these chemicals had ever been detected in wild frog tissue.
"One notable finding was that among sites where pesticides were detected in frog tissue, none of those compounds were detected in the water samples and only a few were detected in the sediment samples," Kelly Smalling, a research hydrologist with the geological survey, said. "This suggests that frogs might be a more reliable indicator of environmental accumulation for these types of pesticides, than either water or soil."
The pesticides found in the frog's tissue could also help scientists understand the cause of the rapid decline in amphibian populations.
"Documenting the presence of environmental contaminants in amphibians found in our protected federal lands is an important first step in finding out whether the frogs are experiencing health consequences from such exposure," Patrick Kleeman, a USGS amphibian ecologist who collected the frog samples, said "Unfortunately, these animals are often exposed to a cocktail of multiple contaminants, making it difficult to parse out the effects of individual contaminants."
