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ABNORMAL AMPHIBIAN MONITORING
Amphibian abnormalities have been addressed in scientific literature for some time, but it was only when middle school students in Minnesota discovered large numbers of abnormal frogs that the general public and the Congress began to notice. That was in 1995 and researchers have been investigating the problem at many levels ever since – including research on national wildlife refuges.
Environmental stressors may cause such abnormalities as missing, extra or unusual body parts. In fact, scientists believe frog abnormalities could be caused by multiple factors that may differ from one site to another. These factors may include changes in climate, predators, parasites, bacteria, fungi and viruses or pollution and contaminants such as pesticides, metals and fertilizer, among others.
The Service launched a nation-wide scientific survey to determine the extent of abnormal frogs on national wildlife refuges in 2000. With the help of refuge staff, volunteers, Friends organizations and at least one student group, simple first-tier assessments of frog abnormalities have been conducted in ponds, wetlands, puddles, and other water bodies on more than 145 refuges in 47 states. This effort represents the first nationwide survey of abnormal amphibians that uses standardized collection and evaluation methods.
During the initial assessment, researchers try to collect 50-100 newly metamorphosed frogs of one species from a single pond and document visible abnormalities. Abnormal frogs are sent to a parasitologist who looks for parasites that cause abnormal limb development. Then the frogs are sent for radiography so that any bone abnormalities can be examined and documented.
Service researchers are beginning to mine years worth of data. We hope to find trends that will help focus additional studies. With the tremendous amount of data that has been collected so far, the Service hopes to get a better understanding about what is happening and what we can do to help
Standard Operating Procedures (SOPs)