Amphibians in Peril
American Green Tree Frog Photograph by Wes Deyton Last Mile Photography
Amphibians are among the oldest lifeforms on Earth. Amphibians have been on the Earth for over 300 million years. There are 6,300 species of amphibians in the world which include Frogs, Salamanders, and Caecilians. There are 4,800 recorded species for frogs and toads in the world. Of the 4.800 species of frogs recorded, the lower 48 States of the USA is home to 90 species of frogs, and North Carolina is home to 30 species of frogs. Amphibians are in peril, frogs and other amphibian’s numbers are decreasing at an alarming rate. It is estimated that 1/3 of the worlds amphibians are threatened with extinction. That is about 1,900 hundred species of frogs that are
Photograph by Michael Fogden, Getty Images
that are currently threatened. Just in the last 10 years 170 species of frogs have become extinct. Amphibian species such as the Golden Toad ,which used to live in the Rainforest of Costa Rica have gone totally extinct.
The massive decline of frogs and other amphibians is due to several reasons which include habitat loss, climate change, and a fungus that causes a deadly disease in frogs and other amphibians. Central and South America have been hit especially hard by this disease caused by the Chytrid Fungus. In South and Central America amphibian populations have been decimated by the disease called Chytridiomycosis , which is caused by the Chytrid fungus. The Chytrid fungus has been found all over the world on every inhabited continent. The Chytrid fungus is not spreading in Europe and Eastern America as much as it is in Western North America and Central and South America. The Chytrid fungus flourishes in the humid and high elevation rainforest of Central and South America. It has become such a serious problem that 2/3 of South and Central America amphibians have become extinct ,which includes the Golden Toad.This fungus gets onto a frog and it makes their skin non permeable by blocking their pores through which air and water move through. A frog can breathe through both its lungs and its skin. Also frogs do not drink water like us, instead they absorb water through their skin. This disease basically causes the frog to dehydrate and die.Scientist believe that the fungus came to this part of the world in the 1940’s when African Clawed Frogs were brought to America, and elsewhere in the world for medical research. The African Clawed Frog is immune to the Chytrid fungus.
American Bullfrog Last Mile Photography
The American Bullfrog also is immune to the effects of Chytrid fungus. The African Clawed frogs were used for research in pregnancy testing. Some escaped and some were turned loose by medical workers, and some came over via the pet trade from Africa.
Cricket Frog Last Mile Photography
Here in North Carolina biologist have noticed a decline in amphibian populations also. Scientist have noticed that the Southern Cricket frog populations have been declining. Scientist have discovered that the Southern Cricket frog has disappeared in the upper coastal plane from the Chowan to the Cape Fear river. The scientist speculate that the Northern Cricket frog maybe running out the Southern Cricket frog .They also speculate that climate change and human development maybe killing these frogs off because they cannot adapt well to wild fluctuations in winter temperatures, as well as human encroachment into their habitat .Another factor that is causing the amphibians population to decline in alarming rates is the Ozone layer depletion.A frogs skin is not a very good UV filter , because intensified UV light causes a frogs immune system to not work as well and causes them to be more susceptible to the disease . Increased UV light also causes frog eggs to not develop properly and creates a much higher mortality rate in developing frogs. Increased droughts have also hurt frogs because they cannot hide in the water to get away from the increased UV radiation, because some of the water sources have dried up.
Bronze Frog photo by Wes Deyton Last Mile Photography
The frog trade has also led to decreasing populations. Rare frogs are often in high demand and people are willing to pay a lot of money for frogs in the illegal pet trade, which brings non native frogs to places that helps spread the Chytrid Fungus.
A 500 million dollar project called Amphibian Ark has been launched to help preserve amphibian species all over the world. Project Arks main members are the International Association of Zoos and Aquarium, Conservation Breeding Specialist Groups,and the Amphibian Specialist Group. These Organizations are all staffed by Amphibian Experts and volunteers that have made it their mission to protect the Earths Amphibians from extinction. The program encourages zoos to take in at 500 species of one Amphibian make sure they are free of Chytrid and captivity breed these amphibians until a way to prevent frogs from succumbing to the Chytrid disease is found.
information about declining amphibian populations please check out Amphibian Ark’s website, and support their work. http://www.amphibianark.org/
Sources
http://animal.discovery.com/endangered-species/frog-extinction.htm
Layton Julia. Are Frogs on the brink of extinction.
http://amphibiaweb.org/declines/
http://uncnews.unc.edu/content/view/6114/74/
Mueller Jennifer. Are All Frog Species in Decline.
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