Study: Farm pollution deforms frogs

Posted by egable on September 25th, 2007 filed in Wildlife

High levels of nutrients used in farming and ranching fuel parasite infections that have cause highly publicized deformities in frogs in ponds and lakes across North America, according to a new study led by the University of Colorado at Boulder.

The study showed increased levels of nitrogen and phosphorus cause sharp hikes in the abundance and reproduction of a snail species that hosts microscopic parasites known as trematodes, according to Pieter Johnson of CU-Boulder’s ecology and evolutionary biology department. The nutrients stimulate algae growth, increasing snail populations and the number of infectious parasites released by snails into ponds and lakes. The parasites subsequently form cysts in the developing limbs of tadpoles causing missing limbs, extra limbs and other severe malformations.

“This is the first study to show that nutrient enrichment drives the abundance of these parasites, increasing levels of amphibian infection and subsequent malformations,” Johnson said in a statement. “The research has implications for both worldwide amphibian declines and for a wide array of diseases potentially linked to nutrient pollution, including cholera, malaria, West Nile virus and diseases affecting coral reefs.”

The Denver Rocky Mountain News and Denver Post covered the story.