Effects On Both Nature and People

A die-off of amphibians can have a profound impact on a wetland area. Amphibians are often the most abundant vertebrates (animals with a backbone) in wetlands. Therefore, their disappearance can lead to a proliferation of insects, their main prey. In addition, reptiles, birds, and mammals that feed on adult amphibians or their larvae are liable to face a serious food shortage.

The problems threatening amphibians may have implications for human life. Some researchers believe that humans are being affected by the same hormone-mimicking chemicals linked to amphibian sexual abnormalities. A few disputed studies in the 1990's found that men were producing fewer sperm than in previous decades, and some scientists speculated that the decline might be due to endocrine disrupters. Other studies in the 1990's linked lower IQ scores in children to these chemicals, but that research, too, was controversial. A more accepted scientific conclusion was that the higher levels of ultraviolet radiation that seemed to be affecting amphibians may be causing a greater incidence of human skin cancer and eye disease.

The loss of amphibian species may in itself have human implications, particularly in the development of new drugs. In 1973, for example, a frog called the gastric brooding frog was discovered in Australia. This frog was of interest to scientists because it was somehow able to switch off the production of digestive chemicals in order to brood its eggs in its stomach. Researchers hoped that learning how the frog did this might lead to new treatments for stomach ulcers. Unfortunately, the gastric brooding frog has not been seen in the wild since 1979 and is thought to be extinct.