Pity the poor frogs: they’re one of the most endangered group of
vertebrates on the planet, and new research shows that two of
the factors in their plight are common, everyday farm chemicals.
The study shows that atrazine, a weedkiller that’s widely used
in agricultural areas, not only boosts the levels of parasitic
flatworms in frog ponds, it also decreases tadpoles’ ability to
fight off infections. If that wasn’t bad enough, previous
research has found that runoff from phosphate fertilizers also
boosts parasite levels. Taken together, researchers say, the
weedkiller and the fertilizers are hitting frogs with a double
whammy. Amphibian populations around the world have been
declining in recent decades, with many species on the brink of
extinction. Infection with any of several species of tiny
flatworms, known as trematodes, can trigger debilitating limb
deformities in frogs. Severe infections can kill the amphibians.
The question was why high rates of those deformities — and,
presumably, trematode infections