It happened one moonlit night when she approached a pond to record the frogs. There was a moment when she realized they had become deeply important to her. The usual rate of deformities in frog populations is between zero and 2 percent.Īs she dug deeper into the mystery of the frogs, Helgen began to feel a closer connection to them than she ever had before. Six-and-a-half-percent of them had deformities. Over the next few years, workers in Minnesota collected more than 13,000 northern leopard frogs, the most common frog in the state. They catalogued frogs with missing legs, fingers and toes, extra legs, partial legs, skin webbing that prevented legs from stretching, and missing or extra eyes. They worked in labs and in the field, around the U.S. She coordinated the research of an informal group of biologists, toxicologists, hydrologists, chemists, experts in endocrines and parasites and animal development. She made it her mission to collect samples of frogs, water, and sediment, and to record conditions with as much detail as possible at each of these locations. The phone calls Helgen received led her to "hot spots" where numerous deformed frogs were found. Snd I simply had never, never, never seen the abundance of abnormalities such as Judy and those students were seeing in Henderson and subsequently throughout Minnesota and even throughout the world," McKinnell said. "I had collected extensively in South Dakota, North Dakota, Minnesota, and in years previous to that in Vermont. McKinnell, now retired, visited Ney Pond. One of them was Bob McKinnell, a professor who spent most of his career studying frogs and cancer at the University of Minnesota. Looking for an explanation, Helgen approached outside experts. When they have problems, it can be a signal that other animals, including humans, may face the same problems eventually. Their skin absorbs what surrounds them, and they move from pond to grass and woods to deeper water and back. Helgen and other scientists regard frogs as a "sentinel species" - they are the proverbial canary in the coal mine. she had a kid bring in a bucket of deformed frogs to school, and it became sort of chilling because we started getting phone calls, and not just from Minnesota, but from people in other states," Helgen said. "We had a call from this teacher in Litchfield. The media jumped on the story and Helgen began getting calls from people who had found their own deformed frogs. The frogs came to represent far more than an abstract scientific question. That hot, sticky August afternoon turned out to be a turning point in Helgen's work and her life. They created a citizens monitoring project, and trained volunteers to use the information to assess the health of wetlands. Colleagues were doing similar work on fish and plants. Essentially, she was studying which wetland dwellers - such as mayflies, beetles, crayfish - can tolerate pollution and which cannot. Helgen's normal work at the MPCA was to develop bio-indicators for wetland health. The pond was manmade: had the digging exposed some toxin in the soil? Were pesticides running off from the farm fields above? Was it damage from the sun? Parasites? Helgen's mind swirled with possible explanations. She examined the frogs, taking careful notes, and brought some of them back to her office for further study. ![]() More than half of the frogs they collected from Ney Pond were grotesquely deformed - with missing legs, or extra legs, or legs that branched unnaturally into multiple sections. Related: Frogs offer signpost to farmland's wildlife impact.
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