Fungus causes concern for amphibian species

By Amanda Phipps
phippsa@thejohnsonian.com

Bill Rogers biology profesorA deadly fungus has spread across many parts of the world and infected amphibians and their eggs, according to the U.S. Fish and Wildlife Service (FWS).

The fungus, Batrachochytrium dendrobatidis, also known as Chytrid fungus, causes the disease chytridiomycosis, which is the primary factor contributing to population declines and extinctions of several amphibian species, according to the FWS website.

Amphibians have thin, moist skin lacking keratin, the protein that makes skin thick and tough, biology professor Bill Rogers said. The amphibians use their skin to breathe; some do not have lungs.

The Chytrid fungus is parasitic and gets into the skin of the animals, Rogers said. Keratosis, a condition in which the skin thickens, is a symptom of the infection that is caused by the animal attempting to rid itself of the fungus. This eventually suffocates the amphibian.

“That has to be a horrible way to die,” he said.

This fungus may affect the Winthrop community in the future as well, Rogers said.

Rogers said the fungus originated in the tropical to subtropical areas of Africa. Though he has not searched for it, Rogers said if the fungus is not yet in South Carolina, it might be able to exist here because it is already in places with climates similar to South Carolina’s.

The fungus has become a national problem and is a concern for the preservation of various amphibian species, according to the FWS website.

The Fish and Wildlife Service petitioned on Sept. 9, 2009, to list amphibians and their eggs as injurious wildlife under the Lacey Act, FWS spokespersonValerie Fellows said.

This act dates back to the 1900s and states that “the Secretary of the Interior is authorized to regulate the importation and transport of species, including offspring and eggs, determined to be injurious to the health and welfare of humans, the interests of agriculture, horticulture or forestry, and the welfare and survival of wildlife resources of the U.S.,” according to the FWS website.

The FWS‘s petition calls for the regulation of fungus-bearing amphibians.

“The request is for the Service to list as injurious only those amphibians not accompanied by a health certificate verifying that they are free of amphibian Chytrid fungus,” Fellows said.
 
Establishing infected amphibians and their eggs as injurious wildlife would mean the transport or importation of these species would be regulated, Fellows said.

“To control the spread of an injurious species, the importation and interstate transport of the listed species are prohibited without a permit issued by the Service,” she said.

The Service provides permits for the interstate transportation of injurious wildlife for scientific, medical, educational or zoological purposes, Fellows said.

The FWS petition calls for a health certificate to accompany the shipments of the amphibians to show they are free of the fungus before they are transported or imported, Fellows said.

“The petitioner and Service are concerned with the spread of the disease that is closely linked to amphibian trade,” she said. “The Service is in no way attempting to curtail the trade or ownership in amphibians, only the spread of the deadly disease.”

Under the Lacey Act, permits cannot be granted for the movement of personal pets. Owners cannot tranport pets across state lines if they are infected with the fungus, Fellows said.

“Amphibian owners would be allowed to transport their pet amphibians to another state provided the animals are accompanied by a health certificate showing the pet is free of Chytrid fungus,” she said. “A permit from the Service would not be required.”

Owners can obtain a health certificate from a qualified laboratory for a small fee, Fellows said.

“If the amphibian remained in the state, it would not need a health certificate or a permit,” she said.

Currently, the U.S. Fish and Wildlife Service is gathering information and has not yet proposed a rule. The Service published a Notice of Inquiry in the Federal Register and the public may submit information about the fungus problem to the FWS through Dec. 16, Fellows said. After review, the Service will decide if action will be taken.

Rogers said the rule may help, but it may be too late.

“The act may help because people cannot import organisms infected with the fungus,” he said, “but the problem is the fungus is already in the U.S. at least, if not South Carolina.”

The fungus is not the only problem affecting the amphibian populations, Rogers said.

“Amphibians are in trouble for lots of reasons,” he said. “It is heartbreaking.”

Transporting and importing exotic species is also a factor influencing the decline of populations, Rogers said.

Amphibians in Africa were able to adjust to a fungus that was not as powerful as it is now, Rogers said. There was a type of ‘evolutionary arms race’ in this area as the amphibians fought against the fungus and the fungus grew in strength. The animals were able to develop defenses to the fungus as it strengthened.

The amphibians in America, however, are being exposed to a fungus that is already more powerful than they are, Rogers said.

“The New World species has not had a chance to develop the defenses against the fungus,” he said.

Humans are part of the problem, Rogers said.

“Amphibians are so vulnerable to the changes people are making to the environment,” he said. “It’s (the amphibians’) environment too.”