Peril in the ponds

Judy Helgen at a favorite Falcon Heights habitat in warmer times. (submitted photo)

A fascinating new book by Roseville writer Judy Helgen uncovers the tragedy happening in our ponds

It is one biologist’s uphill battle to find the answers, and funding, as to why frogs with missing legs, extra legs, eyes where they should not be and worse - are appearing in farm ponds and wetlands.

The initial discovery near Henderson, a sleepy little town on the banks of the Minnesota River, made front-page news in 1995 when a teacher on a field trip with a handful of elementary school students took a closer look at a man-made pond on the Ney family farm and was handed a deformed frog by one of the kids. Then another. Before long, the group had collected a dozen.

The teacher looked at the frogs with missing or extra limbs; looked at the kids, their expectant faces waiting for an answer, and then called the Minnesota Pollution Control Agency.

And that’s how Judy Helgen got involved.

After growing up and going to school on the East Coast, Helgen earned a Ph.D. in zoology with an emphasis on aquatic studies at the University of Minnesota. She then went to work as a research scientist in biological monitoring at the Minnesota Pollution Control Agency.

She said the mystery of the deformed frogs was not high on the MPCA priority list back then. MPCA is an enforcement agency, not an investigative agency she was told at the time.

But Helgen, who has lived in Roseville for 32 years, refused to give up. Scrambling for help and funding where she could find it, she pressed on.

Now retired from the MPCA, she recounts her experiences in a new book, “Perils in the Pond,” published by the University of Massachusetts Press.

What’s deforming the frogs?

“So here’s what we think,” she said recently after returning from an international conference where she met with other concerned researchers.

“There are multiple causes of deformation in frogs, and one is farm chemicals - probably the major possible cause, because chemicals can cause deformities and also weaken frogs, leaving them susceptible to injury and disease,” she said.

Frog predators - wading birds, aquatic animals, even dogs - take their toll but typically don’t leave evidence. Parasites have all but been ruled out as the cause of the deformities.

Farm chemicals seem to be leading the list of suspects, although there is still no proof, Helgen said. Ultraviolet light may play a role, not causing deformities themselves, but acting on the chemicals to make them more toxic.

The concern has always been, could whatever is deforming the frogs progress to humans? That question hasn’t been answered yet as the problem continues: deformed frogs are still being found in several states.

In Minnesota, northern leopard frogs, the most common species, need to migrate before winter, leaving the wetland ponds and either finding depressions under leafy debris in the woods or getting into nearby rivers or lakes and producing an antifreeze-like substance to get them through until spring.

The only thing consistent about the mystery it seems is the number of inconsistencies themselves.

Reports of deformed frogs have dropped off since 2001. While there are fewer reports of deformation, there are also fewer frogs as wetlands shrink from ongoing droughts or are drained to make way for development.

“Most deformed frogs die young,” Helgen said. “Does that mean for a time, some widespread cause harmed many frogs - maybe 20 percent or more instead of the usual 0 to 2 percent - and then it ended? We don’t really know. Nobody’s collecting data.”

An oasis for amphibians

Helgen said she doesn’t have to go far from home to do her frog research. There are many ponds and lakes around Ramsey County where one can still hear the familiar croaking of frogs on summer evenings.

“Kids should get out and experience nature,” Helgen said. “There are even areas right here in Roseville they could investigate.”

She recommended Oasis Pond, located east of Fairview Avenue and north of Terrace Drive and Rosedale Shopping Center, as a good one to look at for the presence of aquatic invertebrates, which are a sign of a healthy wetland.

The U.S. Fish and Wildlife Service is currently wrapping up a 10-year research effort on amphibians at wildlife refuges around the country, and its report is due to be released this year. Helgen said it’s expected to show continuing outbreaks of deformed frogs.

A nature center has been built at the Ney Pond site near Henderson and two of the grade-schoolers who first netted the deformed frogs - now 17-years later - are on the staff.

Denny Lynard can be reached at


To read more ...

Judy Helgen’s new book, “Peril in the Ponds,” is available online as well as at Barnes & Noble in HarMar Mall, at Micawber’s Books in St. Anthony Park and at Common Good Books in St. Paul, to name a few sources.
It was published by the University of Massachusetts Press.

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