Environmental Studies Program



Zach Shirk

Date of this Version

Spring 2010


Amphibians are a unique class of species that are found worldwide except Antarctica and Greenland. They range in size from a few millimeters to over six feet long. Amphibian’s habitats are as various as their size, but one thing in common is that amphibians require an aquatic location to breed. Amphibians live in deserts, mountain prairies, rain forest, wetlands, and almost everywhere in between. Amphibians are an integrated part of most natural ecosystems across the world. Amphibians are a critical part of many food chains; they provide the important link between secondary and tertiary consumers. Amphibians are indicator species in their ecosystems, meaning their health can determine if the ecosystem is healthy or unhealthy. In there ecosystems without amphibians these food chains would be deteriorated and many species would be negatively affected.

Unfortunately various amphibian populations are starting to decline.

Amphibians have already become extinct or have been placed on the endangered and threatened species list. Since 1980, declines in certain amphibian populations have occurred worldwide (Crump et al., 1992). In 2004, amphibian biologists at an international conference announced that 32 percent of amphibian species are currently, threatened, 44 percent of species are in a population decline (Stuart et al., 2004), and 120 amphibian species have likely become extinct in the last 25 years (Blaustein and Wade, 1995). Due to habitat loss and deterioration, global warming, ultraviolet light, acid rain, commercial collection, invasive species, and pesticide use have all been investigated and implicated as causes for these declines in amphibian populations.

Many amphibians inhabit both aquatic and terrestrial ecosystems, allowing them to be exposured to both terrestrial and aquatic environmental changes. Amphibians have highly permeable skin, which makes them more susceptible to toxins in the environment compared to reptiles, mammals, and fish. Amphibian exposed embryonic development, and permeable skin of amphibians heighten their susceptibility to the ramifications of pesticides.