Common insecticide can decimate tadpole populations

How interesting. When I first started reading the article, I expected the tadpoles were harmed because of a lack of insects to eat. Shows how little I know about the diet of tadpoles! I was assuming they eat the same things as adult frogs. You know what they say about what happens when we assume things :)

http://www.eurekalert.org/pub_releases/2008-09/uop-cic092908.php

Public release date: 29-Sep-2008
Contact: Morgan Kelly
University of Pittsburgh
Common insecticide can decimate tadpole populations
Insecticide malathion initiates chain reaction that deprives tadpoles of food source, indirectly killing them at doses too small to kill them directly

PITTSBURGH—The latest findings of a University of Pittsburgh-based project to determine the environmental impact of routine pesticide use suggests that malathion—the most popular insecticide in the United States—can decimate tadpole populations by altering their food chain, according to research published in the Oct. 1 edition of Ecological Applications.

Gradual amounts of malathion that were too small to directly kill developing leopard frog tadpoles instead sparked a biological chain of events that deprived them of their primary food source. As a result, nearly half the tadpoles in the experiment did not reach maturity and would have died in nature. The research was funded by a National Science Foundation grant.

The results build on a nine-year effort by study author Rick Relyea, an associate professor of biological sciences in Pitt's School of Arts and Sciences, to investigate whether there is a link between pesticides and the global decline in amphibians, which are considered an environmental indicator species because of their sensitivity to pollutants. Their deaths may foreshadow the poisoning of other, less environmentally sensitive species—including humans. Relyea published papers in 2005 in Ecological Applications suggesting that the popular weed-killer Roundup® is "extremely lethal" to amphibians in concentrations found in the environment.