and Colleen Winters

There’s no stopping them.
Since the 1995 discovery of deformed frogs in southern Minnesota, these strange green creatures have hopped their way onto newspaper covers and television sets around the world. Now they’re headed straight to the Legislature.
Last week Gov. Arne Carlson proposed to spend $500,000 on deformed frog research as part of his 1998 Bonding Bill, which legislators will vote on this spring.
Researchers at the University and others involved with the Minnesota Pollution Control Agency continue to search for answers to the mystery of these strange creatures.
These misshapen amphibians were first discovered by a group of students on a field trip.
University researchers have come across frogs with as many as nine legs in places where legs shouldn’t be. They’ve also seen frogs with webbed skin behind the knees that reduces mobility.
“And there are some missing legs or parts of legs and missing eyes. I had one with a missing jawbone,” said David Hoppe, a biology professor studying the frogs.
That’s why the pollution control agency named deformed frogs as one of the top environmental issues of 1997.
“We had better find out what it is so that we are certain that we are protecting human populations and animal populations,” said Robert McKinnell, a biology professor working with frogs.
The comparison of frogs and people is not as far-fetched as people might think, said Ralph Pribble, a spokesperson for the Pollution Control Agency. He said frogs are generally thought of as an indicator species because they spend significant portions of their lives in both aquatic and terrestrial environments. That makes them doubly susceptible to environmental dangers, he added.
Adults are not at risk, McKinnell said, but problems could develop for humans in the developmental stages, such as during embryonic and fetus periods.
Different theories have surfaced about the cause of the deformities. Pribble said there could be a chemical in the water from a natural plant toxin causing the frogs to have a reaction. It also might be chemicals from pesticides and herbicides that farmers and industries use, he said.
Still, other researchers have found a connection that points to excessive ultraviolet radiation that causes the cells in the frog to deform during the embryonic stages.
The next possibility suggests that a parasite is burrowing into the skin of the frogs leading to the formation of cysts. The cysts interfere with the development of limbs and cause multiple limbs.
Of course, no one is sure yet, and researchers have kept an open mind on possible causes.
“Our group feels it’s a water-borne contaminant,” Pribble said.
Studies done by the National Institute of Environmental Health Sciences involved frog larvae grown in water from study sites in Minnesota. “It was found that water was able to produce abnormalities in the frogs,” Pribble said.
That created considerable concern because some of the same effects were found from ground water and from drinking water wells at some of those sites, he said.
Researchers in Duluth, however, have conducted some successful experiments with ultraviolet light. In the labs, they increased the amount of the short wavelength, high-frequency light that our atmosphere normally blocks.
Staff members at the Environmental Protection Agency’s Duluth lab, called the Midcontinent Ecology Division, recently released a laboratory study that showed ultraviolet radiation causes frog malformations. The lab plans to continue this research independent of the Pollution Control Agency’s efforts.
Many believe the solution lies in the combination of two or more of these theories feeding off each other. For instance, researchers said the UV light might not be a direct cause in the deformations. But it could cause a chemical in the water, otherwise not harmful to the frogs, to alter in composition and become dangerous.
Although the frogs are an obvious victim in the problem, people do not seem to be in harm’s way, said Hillary Carpenter, environmental toxicologist for the Minnesota Department of Health. The health department is working with the frog research group headed by the Pollution Control Agency.
Pribble said even though there are no immediate hazards to humans, some people who get their drinking water from ponds with high numbers of deformities have been offered bottled water. But only five households receive water from the state as a precaution, he said.
“Everybody wonders, of course, if it has implications for human health,” Pribble said, “and the answer to that question is still pretty much completely unknown, but that is one of the strongest concerns that’s driving the investigative efforts.”
No new findings have been discovered since a December conference on deformed frogs in North Carolina. But another meeting of scientists and advisers is scheduled to meet Wednesday in St. Paul to discuss current views.
Much of the research is in the preliminary stages. In order to be effective, there needs to be a pooled effort of the research results from agencies in all states, Pribble said.
Other states with a high number of deformed frog sightings are Wisconsin, Vermont and Oregon.
At the international level, Canada, Japan, France, Russia and Australia have had similar discoveries, Hoppe said.
Jackie Renner, a spokeswoman in Gov. Carlson’s office, said the issue is something that needs to be addressed and the budget request reflects the urgency.
McKinnell agreed funds are needed to further research, but said they should come from the federal government.
“This is not a local problem, it’s a national and perhaps international problem,” he said. “Federal funds should be available to Minnesota biologists, but in as much as they aren’t, why not spend Minnesota dollars?”