A UCSB researcher co-authored a new study indicating that a sexually reproducing deadly fungus is probably responsible for the sudden decline of Yellow-Legged Frogs throughout the Sierra Nevadas. The study-co-written by Roland Knapp, an ecologist at UCSB’s Sierra Nevada Aquatic Research Lab-indicates that this fungus, rather than non-native predatory fish or pesticides, is responsible for the yellow legged frogs disappearing from 95 percent of their historic range over a 30-year period.
This, in turn, has triggered an ecological chain reaction among species that rely on the frog, such as the garter snake. The frog-killing fungus sexually produces spores that remain in the environment long after the last frog has been killed off. Biologists attempting to re-introduce frogs into streams contaminated with these spores have discovered that the new populations are quickly wiped out as well. Scientists think the fungus kills the frogs by damaging their skins ability to absorb water. Individual frogs can be successfully treated with the application of fungicides, but even treated frogs will die when re-introduced into contaminated bodies of water.