I read in the paper that frogs and toads are becoming scarce and that many of them have extra legs and other deformities. Is this a sign of disease that is causing them to die?
Declines in several amphibian species have been studied for over 20 years.
Yes. Gas bladders, more commonly referred to as swim bladders, allow precise control of buoyancy because the volume of gas they contain can be regulated with ease. Two types of swim bladders exist.
Effects to industries such as oil and gas cannot be predicted, but healthy marshes and barrier islands are known to be important storm buffers to Louisiana's mainland.
Wetlands are transitional areas, sandwiched between permanently flooded deepwater environments and well-drained uplands, here the water table is usually at or near the surface or the land is covered by shallow water.
There does not appear to be one 'smoking gun'; numerous environmental factors are probably responsible for the declines and deformities.
Multiple limbs, missing limbs, and facial abnormalities are the main developmental malformations seen.
Scientists have documented four major 'hot spots' for amphibian declines: western North America, Central America, northeast Australia, and Puerto Rico.
Why should we care about dramatic declines, deformities, and disappearances plaguing many amphibian populations around the world?
Amphibians are good indicators of significant environmental changes. Amphibians, unlike people, breathe at least partly through their skin, which is constantly exposed to everything in their environment.
The worldwide pattern of amphibian declines includes both loss of populations from parts of species' ranges -- the pattern seen in Australia and Central American tropics with stream frogs -- and declines of entire species, such as ranid frogs in Califo
There are about 230 species of amphibians, including about 140 species of salamanders and 90 species of frogs and toads, that can be found in the continental United States.
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