If you’ve ever seen a frog with extra legs or other severe malformations, fertilizer runoff was probably not far behind. According to a University of Colorado study, farming nutrients are leaking into North American lakes and deforming frogs at an alarming rate.
Digital Journal — Increased levels of nitrogen and phosphorous used in farming are stimulating parasitic growth in ponds and lakes, the study explained. Assistant Professor Pieter Johnson of CU-Boulder’s ecology and evolutionary biology department said in a press release:
“The parasites subsequently form cysts in the developing limbs of tadpoles causing missing limbs, extra limbs and other severe malformations.”
The study found that as few as 12 of these parasitic larvae, known as cercariae, can kill or deform a single tadpole by burrowing into their limbs and wreaking havoc on their normal leg development. Once deformed, frogs can rarely survive in the wild, and so the fertilizer runoff from non-organic farms can threaten this amphibian population.
Johnson noted that the amount of phosphorus that runs from rivers into the oceans has increased three times since the industrialization of agriculture. He also pointed out how his study touches upon other issues that should be relevant to the wider world:“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.”
Johnson also said discovering how nutrient pollution affects marine life to influence disease can relate to humans, since many diseases involve multiple hosts.
But on an ecological level, the CU-Boulder study aims to investigate the cause behind certain species’ population decline. An earlier study found 43 per cent of 6,000 worldwide amphibian species were on the decline. Johnson and his team hope to find out how deformation and nutrient pollution are contributing to this crisis.
