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Amphibians as Bioindicators. Tony Li, Michael Ivanov, Jasmine Gallup. Amphibians as Bioindicators. Reasons for why amphibians are good bioindicators include: Amphibians breathe through their skin, so they are much more affected by changes to air and water caused by pollution.
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Amphibians as Bioindicators Tony Li, Michael Ivanov, Jasmine Gallup
Amphibians as Bioindicators Reasons for why amphibians are good bioindicators include: • Amphibians breathe through their skin, so they are much more affected by changes to air and water caused by pollution. • Amphibians require aquatic habitats for reproduction, so they will be directly affected by changes in water quality due to climate changes or human uses. • Amphibians often have to move between habitats (such as from a body of water to an area of land). Disturbances (for example: roads, trails, and traffic) can affect the amphibians’ ability to move between habitats.
Amphibians as Bioindicators • Pollution can cause frogs to become malformed. • Causes for malformation of frogs include parasites, chemicals, and ultraviolet light.
Parasites • The parasite Ribeiroia ondatrae, a type of flatworm, appears to cause frog malformations. • Exposure to the parasite caused high frequencies of severe limb deformations to develop in several amphibian species. • Ribeiroia is not the only cause of frog malformation, as it was not found at all sites where malformed frogs were found. • Some evidence suggests that higher levels of nutrients are the cause of recent increases in the amount of Ribeiroia infections.
Parasites Life cycle of Ribeiroia ondatrae
Chemicals • Pesticides are known to cause malformations or deaths of frogs when present in sufficient quantities. • Methoprene, an insecticide used to control mosquitoes, caused malformations in southern leopard frogs. • Endocrine disruptors, chemicals that interfere with development, and retinoic acid are being studied to determine whether they cause frog deformities. • High concentration of estrogen can also affect limb development.
Ultraviolet light • UV radiation has been shown to cause frog malformities in the laboratory. • Some organic compounds may become toxic when exposed to UV light.
Sources • http://nhguide.dbs.umt.edu/index.php?c=amphibians&m=bioindicators • http://pubs.usgs.gov/fs/fs-043-01/