Every day, find the green thread, the meeting environment of Release. Today is the rule of three: three questions to decipher environmental issues.
Amphibians are not at the party. Threatened by habitat destruction, pesticides or climate change, frogs, toads, newts and other salamanders are also victims of an infectious disease, chytridiomycosis, caused by an aquatic fungus, originally scientists of the disappearance of dozens of species around the world, especially in the Americas and Australia. This deadly epidemic, facilitated by the globalization of trade, was the subject of a series of articles in the journal Science last week. Canadian biologist Dan A. Greenberg, a PhD student at Simon Fraser University in British Columbia, is one of the authors of this work. He decrypts for Release the extent of this crisis for amphibian biodiversity and the solutions to be implemented.
When was this disease first observed in amphibians?
The decline of chytridiomycosis-related amphibian populations would have started in the 1960s; but it accelerated in the 80s. This infectious disease is caused by a fungus, Batrachochytrium dendrobatidis (Bd) which was only discovered in 1998.
How big is the threat to amphibian biodiversity?
The main results of Ben C. Scheele [écologue à l’université nationale australienne de Canberra, ndlr] indicate that at least 501 species of amphibians [soit 6,5 % du total d’espèces de grenouilles et salamandres décrites par les scientifiques à ce jour] are declining and 90 are potentially extinct worldwide due to chytridiomycosis. That makes Batrachochytrium dendrobatidis the most destructive pathogen ever identified for biodiversity.
The decline of amphibian populations attributed to the mainland chytridiomycosis per continent. Photo Anaxyrus boreas, C. Brown, U.S. Geological Survey; Atelopus varius, B.G .; Salamandra salamandra, D. Descouens, Wikimedia Commons; Telmatobius sanborni, I.D.I.R; Cycloramphus boraceiensis, L.F.T .; Cardioglossa melanogaster, M.H .; and Pseudophryne corroboree, C. Doughty
How to protect and conserve these animals in the face of this crisis?
The options are few. The most obvious is to prevent the spread of Batrachochytrium dendrobatidis imposing restrictions on the import trade in amphibians – which has recently been put in place for salamanders in the United States and Canada. But this will only be effective in some cases. Our main hope is that local species adapt by becoming more resistant or tolerant to infection. Other threats to amphibians, such as habitat degradation or climate change, lead to clear choices, including the protection of forests and wetlands, and restrictions on logging.