By Craig Springer/USFWS

Emerging conservation issues demand attention. Chytrid fungus infections in amphibians loom as a national problem, said Dr. Stuart Leon, chief of the U.S. Fish & Wildlife Service’s National Fish Hatchery System (NFHS), addressing a body of scientists from around the country assembled at the National Conservation Training Center, in Shepherdstown, WV. The scientists, including biologists from the Service’s nine Fish Health Centers came together under the auspices of the U.S.

Forest Service and the NFHS to learn more about the perils of a specific Chytrid fungus in amphibians. It’s called Batrachochytrium dendrobatidis, or Bd, and affects frogs and toads across North America and around the world.

The endangered Chiricahua leopard frog in Arizona and New Mexico and the endangered Wyoming toad are just two amphibians that appear directly imperiled by Bd infections.

The first known Bd infections of amphibians in North America occurred in 1961 in Canada. Since then, Bd has been documented over most of the U.S. The question of where the fungus came from or whether it is native to North America remains unanswered.

Infected frogs and toads may have gelatinous globs on the skin, or they may appear completely normal. Infection with Bd may not always be the primary cause of death; the damage to the skin can lead to other infections or an inability of the animal to maintain hydration. In the metamorphic stage, when a tadpole is changing into its adult form, Bd causes gross malformations of hard mouth parts, and ultimately death. Amphibians in the metamorphic stage are the most vulnerable to Bd infections.

“The Service’s Fish Health Centers are uniquely poised to address a potentially serious national problem,” said Dr. Robert Bakal, National Aquatic Animal Health Coordinator for the Service. Bakal, a veterinarian said the meeting of the minds most familiar with the amphibian disease built a bridge with Service fish health biologists to other partners concerned with Bd. Bakal envisions that one of the responses of the Service’s scientific capabilities will be monitoring the natural occurrence of Bd through the National Wild Fish Health Survey. Once protocols are set to sample waters and tissues for the fungus, the Fish Health Centers could make tracking Bd in the wild among its priorities.

For addressing the issue of Bd on National Fish Hatcheries, “Hazard analysis and critical control point planning – HACCP – that’s our common currency,” said Dr. Leon. “HACCP employed and enforced can help prevent the amplification of Bd in the wild.”

But beyond monitoring and prevention, the NFHS can help in recovery of imperiled amphibians, as already underway at Saratoga National Fish Hatchery.

If you have questions about this article, email Craig_Springer@fws.gov

Links

http://www.haccp-nrm.org/

http://www.fws.gov/fisheries/nfhs/fhc/index.htm