Chicago ? Predicting a mass extinction of the world’s frogs, toads, newts and salamanders, 50 international amphibian experts are sending out an unprecedented SOS calling for an urgent global mission to avert a cataclysm.

The plea, published in today’s edition of the journal Science, is meant to be a wake-up call for a broader range of scientists and policy-makers about threats to the Earth’s amphibians, considered canaries in the coal mine for all of nature.

Amphibians are more susceptible to changes in the environment than other animals because they have permeable skin that absorbs water and oxygen, and their lives depend on clean, fresh water.

The amphibian experts are calling for a five-year, $400 million project to pluck certain susceptible species out of harm’s way and put them in safe regional breeding and research centers, as well as zoos and universities around the world.