Investigations in the Lake Champlain Basin of Vermont
The Vermont Amphibian Atlas, Malformed Frogs, and Survey Work on Mt. Mansfield.
Jim Andrews, Research Associate at Middlebury College and Founder of the Vermont Reptile and Amphibian Atlas will discuss the malformed frog problem in the context of the Vermont Amphibian Atlas and higher elevation amphibian survey work on Mt. Mansfield, Vermont.
Malformed Frog Investigations in the Lake Champlain Basin of New York
Ward Stone, New York State Wildlife Pathologist and Eric Paul, New York State Deformed Frog Coordinator will discuss malformed frog reports in the New York portion of the Lake Champlain Basin and future programs to address the issue.
Finding malformed frogs in the Lake Champlain Basin
In 1979, people began finding frogs with missing limbs in the King's Bay Wildlife Management Area, where the Great Chazy River enters Lake Champlain. It was not until nearly 20 years later, late in the summer of 1996, that reports of malformed frogs became more widespread. In Vermont, twelve sites in the Lake Champlain Basin first reported malformed frogs, mostly with missing or partial hind legs or missing or abnormal eyes. Since then, the United States Environmental Protection Agency (USEPA), United States Fish and Wildlife Service (USFWS), Vermont Agency of Natural Resources (VTANR), Middlebury College, and Vermont Public Interest Research Group (VPIRG) have collected frogs in the Lake Champlain Basin and found high percentages of malformities, particularly among northern leopard frogs (Rana pipiens) in certain locations.
What is a malformed frog?
Frog malformations occur sometime during egg fertilization and the development of the very organized and highly specialized organism we know as an adult frog. The intricate and changing relationship between cells and cell layers which gives rise to highly differentiated and specialized tissues is a process we call "morphogenesis." If something goes wrong during morphogenesis and an error occurs in the sequence of cell division, cell migration, cell differentiation, or programmed cell death, pathology is likely. This pathology can be a malformation or a deformation. Malformations represent primary errors in development; deformations occur later in development and usually result from mechanical factors (like trauma to a limb).
What's going on?
Frog malformations can be caused by either genetic or environmental factors. Examples of environmental factors include ultraviolet radiation, hyperthermia, low oxygen, high carbon monoxide, viruses, bacteria, parasites, naturally occurring plant toxins, and toxic chemicals such as pesticides, insecticides, herbicides, or fertilizers.
The high incidence of frog malformity in certain locations in the Champlain Basin suggests that toxic and/or bioactive agents are present in the environment of the affected frogs. Detailed examinations of malformed frogs from Vermont and Minnesota suggest that there is no correlation between viruses, bacteria, or parasites and the frog abnormalities. Skeletal examinations through Radiographic evaluation of malformed leopard frogs suggest that the abnormalities were not caused by trauma or disease.
It appears that the, malformations are caused by a dysfunction in develoment. Studies have shown a high correlation between water and sediment quality and the incidence of frog 'Malformations.
Studies conducted by Dr. Martin Ouellet, a researcher with McGill University in Montreal, show that the incidence of limb malformities averages 20% in agricultural regions subject to a variety of pesticides and other chemicals and only 1.5% in non-agricultural areas.
Why be concerned?
There is something horribly sad about the sight of a frog with a missing or partially formed leg trying to hop. These frogs are emaciated, and they struggle to survive. Basic movement and food procurement are very difficult for them. Malformed frogs that researchers find are barely hanging on to a tenuous existence. It is very likely that many more malformed frogs die before they are found. Frog malformations have serious implications for frog populations and their normal place in the biological system.
In addition to the implications of frog malformities to the frogs themselves and for biodiversity, frogs may be considered as early warning indicators for potential health problems for other organism — including humans. Declines in frog populations or changes in the health of individual frogs are often the first indicator that an ecosystem is in trouble. Other organisms, lower and higher than frogs on the food chain, may-be in trouble too.
The high incidence of frog malformities, and the growing likelihood that the cause is related to chemicals in our water, is cause for concern about the potential implications for human health.
Approximately one third of the Lake Champlain Basin human population relies on the Lake for drinking water. We swim, boat, and fish in its waters. What does the problem of malformed frogs herald for us?
About this program series:
The Malformed Frogs program is part of an ongoing collaboration between the Lake Champlain Committee and SUNY Plattsburgh to provide information on topical Lake issues to Basin citizens. Let us know what issues you would like to see addressed at our Fall 1999 program by contacting LCC via mail, phone or e-mail.
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