Rise of the Mutant Frogs
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
