Sucked this exchange off of the ProMED list server. Thought some of
us might file this away for future discussions of large-systems
effects on biological systems...including the potential role of
chemical contaminants in making life forms more susceptible to these
changes.
We'll have some UW research data to share on this issue this summer.
There is a researcher in the US who insists that any connection
between amphibian declines or mutagenicity and pesticide exposure is
spurious and undemonstrated, and that the real cause is just such a
fungus.
The thing that the NPR copy below overlooks is that there is no
place on earth (last I heard) where pesticides and industrial
chemicals haven't found their way...do I recall correctly that snow
samples in Antarctica revealed trace levels of PCBs and other
contaminants? (It's not like water and air sit still on this
planet.)
peace
misha
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
AMPHIBIAN DEATHS, NEW FUNGUS - AUSTRALIA & AMERICAS
***************************************************
A ProMED-mail post
[see also:
Frog decline and epidemic disease 950731, 950802
Frog Decline and Epidemic Disease (2) 950804 Frog
mortalities - Australia (SE Queensland) 970323180122 Frog
mortalities - Australia (SE Queensland) (02) 970407143831 Frog
mortality: cause found 970921090910 Frogs,
epidemic? - U.K.: RFI 970126094207 Frogs,
epidemic? - U.K.: RFI (02) 970128195904]
[1]
Date: Mon, 06 Jul 1998 12:49:31 -0400
From: Dorothy Preslar
Source: New York Times, 28 Jun 1998
In a paper appearing in the July Proceedings of the National Academy
of Sciences, scientists report a new fungus that they believe is
responsible for the epidemic among frogs and toads of a wide variety
of declining species in rain forests in Australia, and Central and
South America.
Dr. Joyce Longcore, University of Maine at Orono, and colleagues at
the U.S. National Zoo have grown a pure culture of the suspect fungus
and are conducting a final experiment to see if it is the prime factor
in the die-offs.
The researchers believe that the fungus, which grows in the skin of
the frogs, produces multiple layers of skin, thereby preventing
absorption of oxygen, kills by suffocation. However, they are also
investigating the probability that other factors, such as chemical
contamination, may have made the amphibians more susceptible. And they
do not believe the fungus is behind the deformities in Minnesota
frogs.
***
[2]
Date: Tue, 07 Jul 1998 14:08:51 -0400
From: Dorothy Preslar
Source: National Public Radio, 30 June
"Now, for the first time, they've found a culprit -- a newly
discovered fungus they believe is causing the deaths in Panama.
PETER DOSCHEK, PARASITOLOGIST, KINGSTON UNIVERSITY, ENGLAND: It's a
new species, probably a new genus, and it's a completely strange
specimen. These fungi normally live on the bottom of ponds or lakes,
where they act as degraders of vegetable matter. And sometimes -- some
species infect insects and other groups as parasites. But this is the
first time this group of fungus has ever been found to be a parasite
of vertebrates. So, it's completely novel.
LOSURE (interviewer): Doschek says scientists have found the fungus
not only in dead frogs from Panama, but also from Australia,
indicating the same disease has arisen at the same time on two
different continents. The Australian findings, along with the research
of Litz and other American scientists, will be published jointly next
month in the proceedings of the National Academy of Sciences. Doschek,
one of the paper's authors, says it's not clear why what appears to be
a frog epidemic has surfaced now.
DOSCHEK: The thing to remember is that these amphibians are in
pristine habitat. These are very remote, mountainous tropical rain
forests where there's very little human contact. So something's
happened to cause this organism, this pathogen, to become an epidemic
disease.
LOSURE: Many researchers suspect frogs are succumbing now because they
are being physically stressed by worldwide environmental problems,
like pollution, global warming, or higher-than-normal levels of
ultraviolet light from the Earth's thinning ozone layer.
This summer, Litz and other researchers have returned to Panama.
They'll be studying the site where the dead frogs were first found,
and also another site where the disease has not yet hit and the
streams are still full of frogs. The researchers will be taking air
and water samples and testing for pesticides, heavy metals, and other
contaminants that could be carried in by the winds and rain. They'll
study frog populations to see which species are the most susceptible
to the disease wave that appears to be sweeping through the mountains
of Panama.
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Michele Gale-Sinex, communications manager
Center for Integrated Ag Systems
UW-Madison College of Ag and Life Sciences
Voice: (608) 262-8018 FAX: (608) 265-3020
http://www.wisc.edu/cias/
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
In the towers of steel, belief goes on and on
in this heartland, in this heartland soil. --U2
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