Bioindicator Frogs banner 02/12/02
MTU News Story
Survey Shows Few U.P. Frogs with Deformities
by Jim Lutzke

HOUGHTON--A two-year survey conducted by middle and high school students and teachers in western Upper Michigan suggests that amphibians here are apparently much better off than their counterparts in other states, especially nearby Minnesota.

1 Principal investigators Joan Chadde, education program coordinator for the Center for Science and Environmental Outreach at Michigan Technological University, and Dr. David Flaspohler of MTU's School of Forestry and Wood Products, say samples collected in five Upper Peninsula counties showed an incidence of frog deformities at 2 percent, compared to more than 70 percent at some Minnesota sites.

Frog deformities became a national environmental concern in 1995 when a group of students found large numbers of deformed frogs at a pond near Henderson, Minnesota. Since then more than 40 states have recorded deformities in local frog populations, with the highest rates found in Minnesota and Vermont. Wildlife specialists and environmental agencies across the country have been trying to determine the scope of the problem and the cause of the deformities.

1Chadde and Flaspohler knew that hiring professionals or graduate students to conduct large scale surveys would be cost-prohibitive, so they opted instead to try to accomplish their goals with volunteers. After consulting with experts from several states, in the spring of 1999 and again in 2000 they conducted 10-hour teacher training workshops for 6th-12th grade teachers in western and central Upper Michigan. Education and sampling materials were provided by the Wege Foundation and the Michigan Department of Natural Resources Non-Game Wildlife Program. Sessions included species identification and distribution in Michigan, an overview of frog population declines and deformities found in other areas, why frogs are bioindicators of environmental changes, and how to conduct frog population and deformity surveys. Workshop participants were then asked to use their biology students to conduct surveys at local rivers, ponds, lakes, swamps and other wetland areas and submit their findings to the Michigan Tech team for summary and analysis.

"Over the two-year period, teachers and students from Houghton, Gogebic, Marquette, Menominee and Ontonagon counties conducted surveys and submitted their results," said Chadde. "We feel it was important to collect these data so we have a baseline for future comparison in Upper Michigan. We also wanted to show that trained volunteers, such as teachers and students, can help professionals by monitoring a much larger area than would otherwise have been possible, given the shortage of available professionals."

During the survey years, more than a thousand specimens were captured from nine species of amphibians. Only two species, however, exhibited deformities--green frogs and mink frogs. Both of these species spend more of their life cycles in water, compared to tree frogs, which only return to the water to reproduce in the spring. Deformities, such as deformed limbs, missing eyes, extra limbs, and missing limbs, were found in 1.5 percent of green frogs and in 1.7 percent of mink frogs surveyed during the two years.

"While the survey was not a rigorous scientific study, it still generated a lot of useful information," said Flaspohler. " We had a pretty good sample size, and it certainly showed what can be accomplished with a cadre of trained volunteers."

As for what might be causing deformities here and elsewhere, Flaspohler said nobody knows for certain at this point. "In Minnesota and other states, scientists are looking at parasites, pesticides, and even solar radiation as possible causes, but nobody has been able to pin it down as yet and some researchers think it may be due to a combination of factors. " Chadde, along with Dr. Tony Murphy of Hamline University (St. Paul, MN), and Hancock (MI) High School teacher Kristan Schuster, presented a teacher-training program titled "Frogs As Bioindicators" at last year's National Science Teachers' Association (NSTA) convention in Orlando, FL. Their presentation was selected for posting on the NSTA's web site:

See list of presentations above


For more information, contact Joan Chadde at 906-487-3341, email;

or David Flaspohler at 906-487-3608; email

Contact the WUP Center

Last Modified: 02/24/2006


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