Pesticides are again doing a number on California's amphibian population according to a new study by Don Sparling of Southern Illinois University Carbondale in Mongabay. A poisonous cloud of endosulfan is blowing through the Sierra Mountains and into crucial frog habitats. Which frogs are falling victims and why is the die off so dramatic?A pesticide cloud dropped from the skies is blowing into the mountains deforming and killing off California's Pacific tree frogs and foothill yellow-legged frogs, two species native to meadows in California's Sierra Mountains. The Central Valley is an extensive farming community where crops like grapes, peaches, nuts, and tomatoes are grown. The area is also treated with literally hundreds of thousands of pounds of pesticides, according to Sparling. The problem isn't just the pesticide but the timing and method of application.
Timing and Application of Pesticides Are Problematic
Endosulfan is applied in mass by aircraft. It's not the most targeted application and as a result the cloud of toxic mess blows up into the mountains. "These chemicals volatize after being applied, turning into a gaseous state, which could also be picked up and spread into the mountains by wind," says Sparling. Another huge factor is that the pesticides leak into the water supply at an extremely vulnerable time. They are applied in the late winter and early spring, building up in the ice and snow. When the ice and snow begins to melt into the streams and waterways it conflicts with the hatching of the frog's larvae. This is their most vulnerable state when the pesticide laden water is known to cause deformities.
Endosulfan is Already Banned in Europe
The U.S. Environmental Protection Agency is currently evaluating use of the pesticide in the US but Europe and Australia have already banned use of the chemical as a pesticide. Sparling says that frogs are the canary in the coal mine, warning a population of what's to come and while he doesn't abdicate for banning all pesticides, endosulfan's effects are mind numbing and proven.