Is GMO Corn a Threat to Fish?

Have shared in this column some of my concerns over the cultivation and proliferation of genetically modified foods. In response, I have been called anti-scientific, old fashioned and an enemy to progress.

I am none of these. In fact, I have an advanced degree in engineering, which requires a fair amount of science to obtain. One does not seek out such a degree if he believes that man should leave everything the way he found it. In fact, in my day job, I am an inventor, the antithesis of the names I've been called.

However, I also believe in consequences and in understanding the impact of changes we are making to the complex ecological system we find ourselves living in and depending on. No intelligent person would speed down the highway with his eyes closed. And yet that is exactly what we are doing as we go full speed ahead, rolling out powerful biological change agents with little or no comprehension of what impact they will ultimately have on our ecosystem. Here is a case in point. Scientists at Cary Institute of Ecosystem Studies, publishing in the National Academies of the Sciences found maize detritus in 86% of stream sites surveyed. Of these 23% had proteins derived from Bacillus thuringiensis (Bt corn) in their water column. All of these sites had Bt corn planted within 500 meters. The Bt protein, which is closely related to B. anthracis, the agent behind anthrax, is highly toxic to a number of insect species, beyond the specific caterpillars against which it was targeted. Among these, are the chironomidae, or non-biting midges, commonly known as lake flies. These insects are important food for fish such as trout and sturgeon as well as insectivorous birds such as swallows and martins. In fact, many of the fishing flies that anglers use are fashioned in imitation of these little guys. Earlier studies have suggested that Bt corn might also harm the caddis fly, another important fish food.

Not to put too fine a point on this, but it does clearly have some aspects of pushing on a balloon. We develop a new technology that supposedly produces more corn, but we end up with less fish. This despite the fact that Bt corn has been promoted as safe for fish. It’s apparently only safe for fish as long as the fish don’t need to eat.

While Monsanto and other producers of GMO seeds claim that these products will reduce the use of pesticides and herbicides, which they also sell, but that does not seem to be the case. The past 13 years have seen an increase of 318 million pounds of toxic pesticides and herbicides despite the fact that 63% of the US corn crop is now genetically modified to express insecticidal Cry1AB proteins derived from Bacillus thuringiensis. This is most evident with Monsanto’s Roundup Ready crops which have led to a 15-fold increase in sales of Roundup. So it’s pretty clear that someone is benefitting from these innovations, though it’s not necessarily those who are paying for it. In many countries such as Brazil and Argentina, the use of these crops has spawned new strains of Roundup resistant weeds, for which the only answer seems to be to use more Roundup. These farmers are paying more than ever for chemicals and seeds, without necessarily seeing any increase in yields.

Sure, there might be potential benefits to these kinds of manipulations, but we need to do a far better job of understanding their impact before turning them loose on the only planet we have.

[Image credit/nutmeg66/Flickr Creative Commons]

RP Siegel is the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water.  Like airplanes, we all leave behind a vapor trail. And though we can easily see others’, we rarely see our own.

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