Miners used to carry caged canaries down into the mines. If the canary dropped dead from lack of oxygen, they had an early warning that it was time for them to get out. Now scientists think the dramatic increase in deformed frogs is an early warning that the environment is changing. There has been a huge increase in extra legs, deformed legs and eye damage in over 60 species of frogs. Freakish frog deformities have been found in 46 states and four continents.
Scientists who specialize in frogs have noticed for years that there a lot fewer of them around to study, but frog problems first got media attention when horribly deformed frogs were found by Minnesota school children in 1995. In Corvallis, Oregon it?s been discovered that 75-80% of the frogs are deformed. There have always been deformities in amphibians, but nothing like we?re seeing right now.
There are 3 main causes for the sudden rise in deformities. Because frog eggs don?t have a protective outer shell, increased levels of ultraviolet radiation, due to erosion of the ozone layer, can kill embryos and cause eye damage. However, this doesn?t cause one of the worst deformities?the growth of extra legs.
Water pollution, especially pesticide runoff, can cause embryo deformities, but this has been going on for a long time, so it can?t be the direct cause of the increase. A tiny trematode parasite causes a significant number of the leg deformities. During their development, the parasites also infect snails, and the number of snails is increasing at an alarming rate, due to fertilizer runoff and cattle manure that causes algae to bloom, creating more food for them. More snails mean more parasites are around to later infect frogs. Also, water pollution and radiation may weaken frogs? immune systems, making them more vulnerable to the parasites.
Zoologist Andrew Blaustein says, “(These) trends are disturbing in their own right and are also a warning for the planet?Humans and other animals may be affected by the same environmental insults harming amphibians. We should heed their warning.”
Meanwhile, the Calaveras County Fair and Frog Jumping Jubilee in California needs to figure out what to do with 2,000 frogs. Contestants are supposed to put the frogs back where they got them after the annual contest, but they can?t always comply, because it?s illegal.
It’s not against the law to catch the bullfrogs, but it’s illegal to put them back, according to the California Department of Fish and Game Program, because they?re afraid non-native frogs could spread disease or alter the ecosystems. Violators face a $5,000 fine and a year in jail.
Contest officials are trying to find a solution before next May?s contest. The easiest way would be to kill them after the contest, but this seems cruel. Besides, a “frog welfare policy” was started in 1997, requiring humane capture, care and release of the frogs. Captured bullfrogs refuse to eat, so they must be force-fed hamburger meat. No drugs or probes can be used to make a frog jump. Winning contestants have learned that the way to make a frog want to jump is to keep it in a container too small to allow jumping until the contest begins. There?s no information about whether having extra legs makes a frog jump higher.
It?s way past time for scientists to do the seven experiments that could change the world. To learn more,click here and here.
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