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Fifth Year of Field Work Completed for National Abnormal Amphibian Monitoring
Midwest Region, August 1, 2004
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National attention focused on malformed amphibians in 1995 when a group of school children in Minnesota discovered a large number of abnormal and misshapen frogs. In 1997, based on this and an increasing number of reports of abnormal amphibians, Regions 3 and 5 of the U.S. Fish and Wildlife Service collaborated to develop a methodology for monitoring malformed frogs on national wildlife refuges (NWRs) and wetland management districts (WMDs). The objectives of the monitoring were to determine whether this phenomenon was occurring on FWS lands, to develop a database that would include land use surrounding the amphibian monitoring sites, and to contribute to the overall knowledge of the regional and national distribution of the phenomenon. That year, 41 field stations (34 national wildlife refuges and seven wetland management districts) in Region 3 conducted preliminary searches for abnormal frogs.

In 2000, the FWS's Environmental Contaminants Program (currently Environmental Quality Program) received funding as part of the Department of Interior's Amphibian Initiative. The assessments originally done in Regions 3 and 5 (1997) were refined and expanded into a nationwide assessment of more than 43 refuges in 31 states. Approximately 90 refuges and wetland management districts in over 40 states have been monitored at least once through this project.

This year was the fifth year of field work for this nationwide project in Region 3. To date, Region 3 has sampled frogs at 13 refuges/wetland management districts. Sampling consists of collecting frogs from a minimum of two different sites per refuge and examining the frogs for gross abnormalities. Additional diagnostic work, including parasitological evaluations, histological analysis and radiography are performed on abnormal specimens. In 2000, 2001, and 2002, abnormal frogs were sent to the USGS's National Wildlife Health Center in Madison, Wis., for radiograph analysis. Frogs from 2003 and 2004 will be radiographed by Mike Lannoo from the Muncie Center for Medical Education at Ball State University. Starting in 2003, a number of abnormal frogs from various refuges will be sent to the University of Wisconsin at LaCrosse for parasitological analysis. A final parasitology report for the 2003 frogs is now available. Each refuge is sampled at least two years, sometimes longer depending on the incidence of abnormalities.

The Bloomington Field Office, with assistance from the East Lansing Field Office, coordinated the project for Region 3. Staff, volunteers and interns from each participating refuge also provided invaluable support. Through this collaborative effort, close to 1,000 amphibians from eight refuges and wetland management districts were collected and examined this summer. The refuges that participated this year include: Muscatatuck NWR (IN), Clarence Cannon NWR (MO), Two Rivers NWR (IL), Crab Orchard NWR (IL), Upper Mississippi River NWR, McGregor District (IA), Shiawassee NWR (MI), Horicon NWR (WI), Litchfield WMD (MN), Fergus Falls WMD (MN), Union Slough (IA) and Seney NWR (MI). Most abnormalities encountered were missing digits, feet, eyes, and limbs. Several animals with atrophied, bent, or misshapen limbs were also found. At several refuges there was evidence of the parasitic trematode Ribeiroia (which has been shown to cause developmental abnormalities) although the intensities were fairly low. A final report of this season's field work will be completed by the end of the calendar year. In addition, a national database has been developed and data from 2003 and 2004 for Region 3, along with information from other refuges around the nation, has been entered into the database. A fact sheet developed in March of 2003 by the Division of Environmental Quality in the Washington Office is also available and briefly describes the project and its objectives.

Contact Info: Larry Dean, 612-713-5312, Larry_Dean@fws.gov



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