Of Frogs and Men

Q: What do Frogs and People have in Common?

A: Polluted environment.

Frogs are Environment Canaries, by MICHELLE TONKINS

"Frogs are considered as ‘environmental indicators’ and can provide valuable information on the environment they live in and have been likened to the canary down a coal mine.

Frogs are very susceptible to pollutants and as a result are generally only found in healthy environments.

Both the frog’s lifestyle and physiology contribute to their skill in assessing our eco-systems."

• NRDC releases new atrazine report today, Jennifer Sass, Senior Scientist, Washington, D.C."...lab studies in frogs indicates that low levels of atrazine may turn males into females.
  

• Northern Cricket Frog Fact Sheet The decline of the cricket frog apparently began in the 1800's with the clearing, drainage and alteration of thousands of acres of wetland habitat. Aerial spraying of DDT and other chlorinated hydrocarbon pesticides in the 1950's and 1960's is thought to have contributed to the decline of most remaining populations. Other factors that may have contributed to the cricket frog's decline are contamination of ponds by road salt and the introduction of predatory fish, which feed on their eggs.

• Frogs give warning "Amphibians are particularly sensitive to chemical pollution because they live both in water and on land. Furthermore, they breathe through their skin. Some researchers suspect that toxic heavy metals and pesticides building up in aquatic food chains, plus serious air pollution, may be what's killing some frogs, toads, and salamanders." 

• Michigan's Frogs and Toads "Unfortunately, many human activities are harmful to frog and toad populations. Valuable wetland habitats are often drained for agriculture or urban developments. Water pollution may destroy or degrade the ponds, lakes, marshes, and streams that remain. The problem of acid rain has been found to damage amphibian populations in affected areas. And the often unwise use of chemical pesticides is harmful to frogs and toads, both by killing them directly and also by reducing their insect food supply. Thousands of these creatures are killed every year by automobiles, often while crossing roads during migration to breeding sites in spring. An increasing problem is the destruction of wetland environments by the misuse of off road vehicles."

• 10-Limbed Frogs! - Because of contamination with fertilizers "The team tested the role of nitrogen and phosphorus runoff into 36 artificial ponds in Wisconsin, filled with snails, frog tadpoles, (and in some) nitrogen and phosphorus. The pools with supplementary nitrogen and phosphorus (200 mg/l) experienced a boom in their snail population (by 50 %), parasitic worm egg production (by 300 %) and malformed frogs (by 200-500 %). "The amount of phosphorus that runs from rivers into the oceans has increased about three-fold since the industrialization of agriculture.", Johnson also said." 
  

• Amphibian declines: the conservation status of United States species By Michael J. Lanno