October 11, 2007

US study suggest GM corn may affect ecosystems

GM corn might harm aquatic ecosystems by killing off other insects in the system, a US university study suggested.

Pollen and other plant parts containing toxins from genetically engineered Bt corn are washing into streams near cornfields, a study by Indiana University Assistant Professor Todd Royer suggested. Bt corn is widely grown in the US.

The study also included Emma Rosi-Marshall of Loyola University, Jennifer Tank of the University of Notre Dame and Matt Whiles of Southern Illinois University.

The plant parts are in turn consumed by caddisflies- an aquatic insect related to the insects targeted by the toxin in Bt corn.

The researchers' study showed that consumption of these corn byproducts produced increased mortality and reduced growth in the insects. 

Caddisflies are a food source for higher organisms, such as fish and amphibians.

All parts of the system need to be protected if an ecosystem is to function, Royer stressed.

The study appears in the Proceedings of the National Academies of Sciences.