A field survey led by
Jason Rohr of the University of South Florida has come up with the finding that
chemical Atrazine in fertilizers is the villain behind the decline of frogs in
US. Atrazine harms the amphibians' immune defenses against infection. The
effects of this chemical is boosted in the wild by phosphate fertilizers.
Runoff from fertilizers into ponds encourages the proliferation of snails which
acts as a natural host to the flatworm parasite. The flatworms, called trematodes,
cause limb malformations, kidney damage and sometimes death in several species
of frog. Atrazine is manufactured by a Swiss-based company, Syngenta tahrcountry