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> Frequently Asked Questions about Deformed Frogs
Frequently Asked Questions about Deformed Frogs
1. When did this first start?
The MPCA was first involved in investigating abnormal frogs reported
from the Granite Falls area in 1993. Work in the area in 1994 turned
up no abnormal animals, but provided basic information. In August of
1995, students from the New Country School in LeSueur, Minnesota found
large numbers of deformed frogs in a wetland they were studying near
Henderson, Minnesota. Before the end of that season, reports of similar
frogs occurred elsewhere in the Minnesota River Valley.
2. Do we know what is causing it?
Not yet. According to the Minnesota Pollution Control Agency and the
National Institute of Environmental Health Sciences, recent test results
indicate that something in the water from research sites is causing
the abnormalities. The causative agent itself is still unknown. Studies
are still being conducted to determine if it is a chemical, parasite,
ultraviolet radiation, or additional factors.
3. Where is it coming from? Since the agent causing
the malformations is unknown, the source is also a mystery. Does it
come from the air or from the land? Is it "natural" or man-made? We
don't know.
4. Where are the frogs being found?
Reports of malformed amphibians have been reported in 35 states in the
U.S. and 3 provinces in Canada since 1996. In Minnesota, nearly three-quarters
of our 87 counties have reported malformed frogs since 1996. A map of
national reports is available at the North
American Reporting Center for Amphibian Malformations.
5. Does Minnesota have more deformed frogs than other states?
Minnesota has had probably more reports of malformed frogs than other
states. This may be due to increased public awareness of the issue and
not necessarily because our numbers of malformed frogs are higher. However,
biologists with nearly 40 years of experience in surveying frog populations
here have never seen abnormalities to the extent they are present in
the state now. This appears to be a recent phenomenon in Minnesota.
6. What kinds of deformities do the frogs have?
Some frogs have missing eyes, but most problems are associated with
the limbs, especially the hind legs. These deformities typically include
missing limbs, extra limbs, partial limbs, limbs that are bent and contorted,
or limbs that have little muscle, or that have branched at various points
along the limb. Problems in the digestive, urinary and reproductive
organs have also been found in frogs with external deformities.
7. Can the deformed frogs still function?
Many of the deformed frogs can still function; however their ability
to eat, move, migrate, and avoid predators can be slightly or greatly
hindered depending upon the severity of the malformation(s). Few frogs
live into the second year -- it appears they don't survive the winter.
8. What kinds of frogs in Minnesota have been found to be
malformed?
In Minnesota, abnormalities have been documented mostly in the northern
leopard frog, and to a lesser extent in wood frogs, green frogs, mink
frogs, gray treefrogs, spring peepers and American toads.
9. Have other of kinds of animals in North America been found
to be malformed?
We have also heard of some malformations in bullfrogs, gray treefrogs,
Pacific treefrogs, American toads, long-toed salamanders, tiger salamanders,
and spotted salamanders. But, mostly it is frogs.
10. What are the types of places where they are found?
Malformed frogs have typically been found in wetlands or ponds, depending
upon the species and the type of environment for which they are best
suited. They have also been found in both urban (in town) and rural
(in the country) areas of the state. There doesn't appear to be any
geographic pattern in the findings at this time.
11. Is the water the frogs live in unsafe for human use?
Recent studies showed that well water from several sites in Minnesota
can produce frog deformities. This has caused some people to wonder
if their drinking water is safe. Standard drinking-water tests were
run on the water, and nothing was found. Tests are being run now to
identify what in the water causes frog deformities, but it may be some
time before we know what it is, or whether it can affect humans. Until
more is known, there is no scientific evidence that the water is unsafe
for humans.
12. What is MPCA doing about it?
From 1998 to 2000, the Minnesota Governor and Legislature gave the MPCA
special funding to study the frogs. The MPCA worked primarily with researchers
and scientists from the University of Minnesota, the National Institute
of Environmental Health Sciences, the US Geological Survey and also
with the National Wildlife Health Center and the U.S. Environmental
Protection to investigate the problem. These partners provided extensive
chemical and toxicological analysis of the water and sediments, and
characterized the internal abnormalities and analyzed parasites and
microorganisms. As of July 1, 2001, funding was eliminated for the MPCA
to study the frogs.
13. Where can I find more information?
- Contact:
Ralph Pribble,
MPCA Public Information Office
651-757-2657 or (800) 657-3864.
- Visit these Web sites:
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