A deadly fungus, chytrid, is attacking frogs’ skin and wiping out hundreds of species worldwide. A chytrid infection prevents the normal movement of water and nutrients through the amphibians’s skin. 

In the San Francisco Bay Area, Mountain yellow-legged frogs, found only in California’s alpine lakes, have been in steep decline due to the fungus (as well as predation by non-native trout). More than 90 percent of the population has disappeared.  

Now in a last-ditch effort, scientists are trying something new: build defenses against the fungus through a kind of fungus “vaccine.”

Read more about the effort to battle chytrid fungus here. And watch the video by PBS Digital Studios’ Deep Look here.

Video Credit: Josh Cassidy/KQED