http://dsc.discovery.com/news/2007/09/25/deformedfrog_ani.html?category=animals&guid=20070925090030&dcitc=w01-101-ae-0003Why we hear more now about frogs without limbs or extra limbs.
There is a parasite called trematodes that grow in snails. The snails eat algae. The runoff from farms cause an increase in algae. The increase in algae cause an increase in the snail population because they have more to eat. The more snails there are the more the trematodes parasites there are to infect tadpoles causing the tadpoles to form cysts in the limbs that the tadpoles are developing that cause the deformities. Water birds then eat the frogs. The birds excrement carry the parasite back into the ecosystem where they infect the snails, and on the cycle goes.
More about Trematodes ( Flukes )
http://pathmicro.med.sc.edu/parasitology/trematodes.htmThere are different kinds of flukes the ones that do the most harm to man are blood flukes, intestinal fluke, liver fluke, and lung fluke.
Flukes and fish
http://aquarium-answers.blogspot.com/2007/03/trematodes-and-nematodes-in-fish.htmlMore about Trematodes from Wikipedia
http://en.wikipedia.org/wiki/TrematodaDeformed Frogs in Minnesota ---- this is an excellent article about how it is being investigated and the findings.
http://www.cgfi.org/materials/key_pubs/rachel-carson-syndrome-minnesota-deformed-frogs.htmThe same parasite that causes swimmer itch in humans is the one that causes the deformities in the frogs. Could the same chemical run off that causes the algae to grow also cause the frogs immune system to be less able to fight off the infection from the flukes?
National Geographic
http://news.nationalgeographic.com/news/2002/07/0709_020709_deformedfrogs.htmlMore information about the frogs and tadpoles.
http://web.clark.edu/sclark/Sample%20Abstracts.htmWhat are people finding in their ponds....
http://www.smm.org/buzz/blog/mystery_of_the_freaky_frogs#comment