Dilemmas in Amphibian Management: Disease and Translocation, a Group Discussion

Dawne Becker

California Dept. of Fish and Game

Eastern Sierra and Inland Deserts Region, Bishop, CA

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ABSTRACT

BECKER, DAWNE
California Department of Fish & Game, Eastern Sierra and Inland Deserts Region, Bishop, CA, dbecker@dfg.ca.gov

Dilemmas in Amphibian Management: Disease and Translocation, a Group Discussion

Researchers and managers working on draft conservation strategies for Sierra Nevada amphibians focused on many issues, including identification of threats, feasibility of conducting restoration projects, the potential need for translocations, and genetics. Conservative management actions were recommended to avoid genetic manipulations, but at the time, disease was not suspected as having such a large role with regard to restoration and management. We now know otherwise. The focus will be on generating a group discussion on amphibian relocations and their value—in the presence of disease—to ascertain whether or not managers should continue Rana muscosa (RaMu)-specific restoration/translocation projects in areas where the nearest Ramu populations have been infected with chytridiomycosis. Although other researchers and agencies are facing the same dilemma, a regional California Department of Fish & Game project was the impetus for this discussion. While most of our past and ongoing restoration projects have occurred where an adjacent RaMu population would benefit without active translocation, we now have a newly-fishless water with no adjacent RaMu. We are awaiting the verdict, but suspect that disease has infected the only RaMu populations within the same basin. Do we continue with translocations, possibly extending the range of the disease? Do we discontinue translocations, but wait for further knowledge that may guide us appropriately? Will the public, and just as importantly, USFWS, support restoration projects that result in fishless waters without nearby frog populations and without immediate plans for translocation? Will disease persist if infected tadpoles are transferred into new waters? Initial results by Vredenberg’s group (see poster), indicate that non-infected tadpoles transplanted into fishless waters formerly occupied by frogs, but extirpated by disease, have survived without contracting chytrid. Do we have other options that may benefit both amphibians and science? We’re testing for Chytrid (and using methods that reduce the likelihood of us spreading it), but irido- and rana-viruses are present in the Sierra Nevada. How do we deal with this, and perhaps other undetected hitchhikers? While assuming that there is not just one “right” answer, it would be much appreciated to hear the combined professional opinions of the group.