experiment

New study shows Roundup pesticide kills fish; U.S. heading toward OKing more 'Roundup-Ready' genetically engineered farm acreage

Roundup is one of the most widely used pesticides in the world. But it increases the incidence of disease in fish, a new study shows. And yet it looks like the government is about to greatly expand the U.S. acreage where it is applied by approving planting of vast swaths of genetically engineered alfalfa. These “Roundup-Ready” hayfields worry opponents of GE foods, and this latest news about the effect on fish is bound to stir the pot some more. (The opportunity for public comment on allowing GE alfalfa ends soon, btw.)

The new fish study, out of New Zealand, showed that when applied at recommended rates on fields near a freshwater stream, Roundup didn’t kill young freshwater fish outright. Score one point for Monsanto, Roundup’s manufacturer.

However, what Roundup did at this relatively dilute concentration was to increase the production of worm that’s a parasite of the fish, and comes from a particular snail. And the combination of more parasites and moderate levels of Roundup – aka “glyphosate” – produced what scientists called “significantly reduced fish survival.” They concluded:

"This is the first study to show that parasites and glyphosate can act synergistically on aquatic vertebrates at environmentally relevant concentrations, and that glyphosate might increase the risk of disease in fish. Our results have important implications when identifying risks to aquatic communities and suggest that threshold levels of glyphosate currently set by regulatory authorities do not adequately protect freshwater systems."