Insecticides from genetically modified corn present in adjacent streams

Insecticides from genetically modified corn present in adjacent streams
Recognizing the tight linkage between agricultural practices and adjacent aquatic ecosystems, like headwater streams, will help ensure the health and productivity of both. Credit: Photo credit: Google Maps.

In a paper published this week in the Proceedings of the National Academy of Sciences, Cary Institute aquatic ecologist Dr. Emma Rosi-Marshall and colleagues report that streams throughout the Midwestern Corn Belt are receiving insecticidal proteins that originate from adjacent genetically modified crops. The protein enters streams through runoff and when corn leaves, stalks, and plant parts are washed into stream channels.

Genetically-modified plants are a mainstay of large-scale agriculture in the American Midwest, where corn is a dominant crop. In 2009, more than 85% of U.S. were genetically modified to repel pests and/or resist herbicide exposure. Corn engineered to release an insecticide that wards off the European corn borer, commonly referred to as Bt corn, comprised 63% of crops. The tissue of these plants has been modified to express insecticidal proteins, one of which is commonly known as Cry1Ab.

Following an assessment of 217 stream sites in Indiana, the paper's authors found dissolved Cry1Ab proteins from Bt corn present in stream water at nearly a quarter of the sites, including headwater streams. Eighty-six percent of the sampled sites contained corn leaves, husks, stalks, or cobs in their channels; at 13% of these sites corn byproducts contained detectable Cry1Ab proteins. The study was conducted six months after crop harvest, indicating that the insecticidal proteins in crop byproducts can persist in the landscape.

Using these data, U.S. Department of Agriculture land cover data, and GIS modeling, the authors found that all of the stream sites with detectable Cry1Ab insecticidal proteins were located within 500 meters of a . Furthermore, given current agricultural land use patterns, 91% percent of the streams and rivers throughout Iowa, Illinois, and Indiana —some 159,000 miles of waterways—are also located within 500 meters of corn fields.

Rosi-Marshall comments, "Our research adds to the growing body of evidence that corn crop byproducts can be dispersed throughout a stream network, and that the compounds associated with genetically-modified crops, such as insecticidal proteins, can enter nearby water bodies."

After corn crops are harvested, a common agricultural practice is to leave discarded plant material on the fields. This "no-till" form of agriculture minimizes soil erosion, but it also sets the stage for corn byproducts to enter nearby stream channels.

Rosi-Marshall concludes, "The tight linkage between corn fields and streams warrants further research into how corn byproducts, including Cr1Ab insecticidal proteins, potentially impact non-target ecosystems, such as streams and wetlands." These corn byproducts may alter the health of freshwaters. Ultimately, streams that originate in the drain into the Mississippi River and the Great Lakes.

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Citation: Insecticides from genetically modified corn present in adjacent streams (2010, September 27) retrieved 23 July 2019 from
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Sep 27, 2010
No telling what this stuff is doing to the environment.

Sep 27, 2010
So we now have what amounts to dumping of pesticides into adjacent waterways via the GM corn. If this is a concern for waterways, how about for what is ingested in food by people? Used to be you could try to wash pesticides off of produce before eating, but now the pesticide is in each cell of the produce, forcing the consumer to eat it along with the food. How on Earth did this kind of thing get by the regulatory agencies?

Sep 27, 2010
All they said was it was detectable they never said what levels it was detected at. For all we know its a million times lower the level it would have been at using conventional pesticides don't jump to conculsion. Its always easy to condem out of hand lets have all the facts.

Sep 27, 2010
Monsanto. Creators of agent orange. shills for and vehicle for the machinations some of the worst killers in the world.

Monsanto, enemy of all freedom seeking and free thinking men.

Worse than most of the top pharmaceutical companies, combined. A core component of world depopulation.

They even have crews out there to sue farmers when their GM crops cross-contaminate (pollination) the non-gm farmer's fields. destroying all farmers they can, the ones who defy their desire to control foods and to poison those foods.

Monsanto, a nightmare corporation. However, it is the people behind it you need to take note of.

Monsanto is a vehicle..... it is the drivers you want to take down.

When you concentrate the pesticides when concentrating the 'corn' you get pesticide concentrations of extreme levels in the high fructose corn syrup. You know, the crap that is killing people when they drink that 'sugared' (corned) pop.

Sep 28, 2010
Instead non-GM crop owners should be suing Monsanto for contaminating their crops. Monsanto know this and are getting in first.

Sep 28, 2010
There is a seed death gene in the next generation GM products Monsato is attempting to release into nature. Like the Roundup resistant plants they spread and hybridize with neighboring fields and then the sue the poor farmer into submission for "stealing". Now they wont have a need for lawyers. The spreading of that will prevent farmers from having any seeds. If they get away with this we could have a global eradication of all Heirloom plants. That would make Monsanto the only people able to make food of any sort. Is that an acceptable practice? Monsanto is a rogue wild eyed worl domination creature itself.

Sep 28, 2010
I think a couple important questions were not touched on here:
- If the corn wasn't GM, and instead insecticides had to be sprayed on the fields, how would the quantities entering nearby waterways compare?
- How does the environment impact of Cry1Ab compare to that of regular pesticides?

Sep 28, 2010
If they sprayed the insecticide, at least the chemicals would be locally confined. With the insecticide inside the plant, it is broadcast throughout the food chain. You could choose not to drink the water, but how do you choose not to eat the corn? BT works by "blowing up" insects' innards. One wonders if people who develop intestinal tract illness such as irritable bowel syndrome are reacting to the BT.

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