A recent rule put in place in 2016 restricting the international import of 201 salamander species into the United States aimed to prevent the newly discovered deadly salamander fungal disease, Batrachochytrium salamandrivorans (Bsal), from entering the country. In a new study published Oct. 13 in Scientific Reports based on help from the Amphibian Survival Alliance (ASA), Smithsonian Institution scientists reveal that the moratorium seemingly has a chance to do its job effectively.
“When the moratorium went into effect, we did not know if Bsal was already in the United States in pet salamanders and whether we were closing the barn door only after the horse had already escaped,” said Brian Gratwicke, ASA global council member, Smithsonian Conservation Biology Institute amphibian conservation biologist and paper senior author. “Our study did not find the pathogen in pet salamander populations in the United States, which is good news for native salamanders, especially the Appalachian region—a salamander biodiversity hotspot. It also means that we must continue to be vigilant and prevent the disease from entering the United States.”
The study marks the first general survey for Bsal in pet salamanders in the United States. The researchers worked with the ASA to mail out sampling kits to salamander pet owners. In return the team received skin swab samples from 639 salamanders belonging to 65 species, many of which are potential carriers of Bsal. None of the samples came back with evidence of Bsal, according to tests conducted in SCBI’s Center for Conservation Genomics. The Scientific Reports study complements SCBI’s ongoing tests of salamanders in the wild, which have also come back negative for Bsal.
The Lacey Act was used to list 201 species of salamanders that the United States Fish and Wildlife Service judged as “injurious wildlife” (those shown to be carriers or to be lethally affected by Bsal). As a result, these species cannot be imported from other countries with a permit for research or conservation use. According to the paper, the Lacey Act decision reduced the number of salamanders imported to the United States from 2015 to 2016 by 98.4 percent.
Bsal has been detected in the wild in the Netherlands, Belgium, Germany and Vietnam, and in captive individuals in the United Kingdom and Germany. An article published this month in the journal Amphibia-Reptilia reports that Bsal has also been found on frogs in the pet trade in Germany. The study found Bsal on small-webbed bell toads, which are closely related to the Oriental fire-bellied toad, a species traded in massive numbers with more than 3.5 million specimens traded in the United States between 2001 and 2009.
The discovery of this new potential disease carrier has spurred the ASA to join other organizations in urging the USFWS to place a moratorium on amphibian imports until a system is in place to ensure imports are free of Bsal and other diseases.
“Preventing Bsal from entering North America is currently the only viable strategy we have to protect native amphibians and amphibian captive populations from Bsal,” said Reid Harris, ASA director of international disease mitigation and professor of biology (emeritus) at James Madison University. “The finding of no Bsal among a sample of salamander pet owners is welcome news, and we need to do whatever we can to continue to protect our 190 native species of salamanders.”
Bsal was discovered after populations of fire salamanders in the Netherlands experienced catastrophic declines from the disease, which was likely introduced from Asia, the source of most international exports of salamander species for the pet trade. Bsal is similar to a lethal fungus called Batrachochytrium dendrobatidis (Bd), which has been a major driver of global amphibian declines and extinctions.
The Scientific Reports paper’s additional authors are Blake Klocke, Matthew Becker, Robert Fleischer and Carly Muletz-Wolz, Smithsonian Conservation Biology Institute; James Lewis, Rainforest Trust; and Larry Rockwood and A. Alonso Aguirre, George Mason University.
Photo: Researchers swabbing an emperor newt at the Smithsonian National Zoological Park. Emperor newts belong to a genus of newts from Asia that are currently subjected to the U.S. Fish and Wildlife Service’s moratorium on salamander imports because of the risk that they may carry the deadly salamander fungal disease, Batrachochytrium salamandrivorans (Bsal). (Photo by Brian Gratwicke)