Native salamander populations in North America could be decimated by a deadly fungus identified in 2013, unless U.S. officials make an immediate move to stop salamander importation, according to an urgent new report.
At the highest risk for salamander declines and extinctions, if the fatal Batrachochytrium salamandrivorans (Bsal) fungus makes its way into the regions, are the southeastern United States, particularly the southern extent of the Appalachian Mountain range and its southern neighboring region, the Pacific Northwest and the Sierra Nevada, and the central highlands of Mexico, says San Francisco State University biologist Vance Vredenburg, his graduate student Tiffany Yap and their colleagues at the University of California, Berkeley and the University of California, Los Angeles.
“This is an imminent threat, and a place where policy could have a very positive effect,” Vredenburg said. “We actually have a decent chance of preventing a major catastrophe.”
The fact that salamanders are popular around the world as pets, and often are traded across borders, has scientists worried that the fungus could spread from Asia, where it likely originated, to other parts of the globe.
Immediate Ban Sought
Vredenburg and his coauthors on the study are asking the U.S. Fish and Wildlife Service to place an immediate ban on live salamander imports to the U.S. until there is a plan in place to detect and prevent the spread of Bsal. Although the ban has been supported by key scientists for some time, including in a prominent op-ed in the New York Times last year, the government has been slow to act.
Salamanders are one of the most plentiful vertebrate animals in many North American ecosystems and play a number of key ecological roles.
“They are very important predators of insects, but also an important part of the food chain,” said Vredenburg, an associate professor of biology.
The Bsal fungus probably originated in Asian species of salamander that are traded as popular pets around the world. When the fungus made its way into Europe through the pet trade, it caused a 96 percent fatality rate among the European salamander species that it infected. It was also fatal to American salamanders exposed to the fungus in the lab.
The main carriers of Bsal are thought to be the blue-tailed fire-bellied newt (Cynops cyanurus), the Japanese fire-bellied newt (Cynops pyrrhogaster), and the Tam Dao or Vietnamese salamander (Paramesotriton deloustali).
91 percent of pet salamanders imported to North America come from either the Cynops or Paramesotriton groups.
Vredenburg is afraid that the salamanders might be on the brink of an ecological crisis that is all too familiar to him. For over a decade, he has studied the impact of a similarly deadly fungus, called Batrachochytrium dendrobatidis (Bd).
More than 200 species of amphibians have gone extinct or are near to extinction as a result of Bd infection, making it the most devastating infectious wildlife disease ever recorded.
“I have seen the effects of Bd on frogs, to the point where I’ve seen tens of thousands of animals die in the wild in pristine areas, here in California, right in front of my eyes,” Vredenburg said. “It is just an unbelievable sight to see all these dead animals.”
The heartbreaking work might have a silver lining, he said, if it can be used to save the salamanders from a similar plight.
Vredenburg is the co-founder of AmphibiaWeb, an online database of information on amphibian biology that receives 7.3 million queries each year. Salamanders are astonishing animals, he said, ranging from species that live 35 feet up in the trees to others that roll into balls and hurl themselves off cliffs to escape predators.
Orginial Study: Averting a North American biodiversity crisis
Photo: The Ensatina salamander (Ensatina eschscholtzii), a lungless salamander common along the west coast of the US, is one of hundreds of species of salamanders endemic to North America threatened by an emerging infectious pathogen. Credit: Tiffany Yap