Experts from California are urging for immediate ban on salamander imports so as to fend off deadly fungus called Batrachochytrium salamandrivorans (Bsal) which has already wreaked havoc in Europe.
Vance Vredenburg, a San Francisco State University biologist, and his graduate student Tiffany Yap and their colleagues at the University of California, Berkeley and the University of California, Los Angeles have called on the U.S. Fish and Wildlife Service to immediately halt salamander imports until there is a plan to detect and prevent the spread of the fungus.
“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.”
Salamanders are one of the most popular pets globally and nearly three quarters of a million salamanders were imported into the U.S. between 2010 and 2014, 99 per cent of them from Asia, where the fungus likely originated.
The blue-tailed fire-bellied newt (Cynops cyanurus), the Japanese fire-bellied newt (Cynops pyrrhogaster), and the Tam Dao or Vietnamese salamander (Paramesotriton deloustali) are thought to be the main carriers of Bsal. Alarmingly, 91 percent of pet salamanders imported to North America come from either the Cynops or Paramesotriton groups.
Because of this, the scientists and other herpetologists worry that the fungus could spread from Asia, where the salamanders seem to tolerate the fungus, to more vulnerable parts of the globe. Since it was first recognized in 2013, the fungus has caused a 96 per cent fatality rate among the European salamander species that it infected.
Experts are calling out for the urgent ban because a recent study showed that two common American salamanders – the rough-skinned newt found all over the Pacific Coast and the iconic Eastern newt of the Eastern U.S. – are highly susceptible to the fungus. The fungus is related to another fungus – Batrachochytrium dendrobatidis (Bd), or chytrid – that has already severely impacted frog and salamander populations around the globe.
“This fungus is much worse than the chytrid fungus, which is more like a lingering disease that affects the skin and puts stress on the salamander until it dies,” said David Wake, a professor in the graduate school at UC Berkeley and the director and founder of AmphibiaWeb, an online database of information on amphibian biology. “Bsal is an acute infection that just turns them into little masses of slime in three to four days.”
Although a ban is supported by key scientists and the Center for Biological Diversity initiated an online petition in May to institute a ban, the federal government has been slow to act.
“There is a lot at stake here if the U.S. Fish and Wildlife Service doesn’t stop imports now to prevent the introduction of this devastating pathogen to North America,” said co-author Michelle Koo, a UC Berkeley researcher in the Museum of Vertebrate Zoology and associate director of AmphibiaWeb, an online database of information on amphibian biology.
To map out high-risk regions of Bsal infection in North America, the research team looked at habitats where the fungus might thrive, based on its Asian carrier locations, along with data on how many different species might be threatened in those areas and the location of major U.S. ports of entry for salamander trade between 2010 and 2014.
Vredenburg fears that the salamanders might be on the verge of an ecological crisis that is all too familiar to him. For more than 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.
A paper describing the potential effects of the fungus on U.S. and Mexican salamanders will appear in the July 31 issue of the journal Science.