Rise of
the Mutant Frogs
Rise
of the Mutant Frogs sounds like a sci-fi horror film, but it's
reality in many states across
North America. Studies show that frog-deforming
infections caused by tiny parasites are increasing because of North
American farms' nutrient-rich watershed.
Farm runoff
is rich is nitrogen and phosphorus, which causes algae to crow.
The increase in algae also increases the snail population,
and these snails are hosts to microscopic parasites called trematodes
(a type of fluke or parasitic worm). The increase is trematodes
is what thought to be causing the frog
mutations. Still with me?
For decades, many communities have noticed a steep decline in
the local frog populations. Although not pinpointed to one cause,
the decline may be contributed to habitat
loss, global warming and emerging diseases such as one caused
by chytrid fungus. Nutrient pollution, from the previously mentioned
farm run-off, and limb malformations may also be contributing to
the decline.
A worldwide study of more than 6,000 species of amphibians recently
concluded that 32 percent were threatened and 43 percent were
declining in population.
When
amphibian declines were first presented as a conservation issue
in the late 1980s, some scientists remained unconvinced of the
reality and gravity of the conservation issue. Some biologists
argued that populations of most organisms, amphibians included,
naturally vary through time. They argued that the lack of long-term
data on amphibian populations made it difficult to determine
whether the anecdotal declines reported by biologists were worth
the (often limited) time and money of conservation efforts.
However, since this initial skepticism, biologists have come to
a consensus that declines in amphibian populations are a real and
severe threat to biodiversity. This consensus emerged with an
increase in the number of studies that monitored amphibian populations,
direct observation of mass mortality in pristine sites that lacked
apparent cause, and an awareness that declines in amphibian populations
are truly global in nature.
To see a list
of frogs in your area that are currently being threatened, visit
the Worldwildlife organization here.
September 25, 2007, Happyhippie.com newswire