Bye-Bye Caddisfly?

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Here in Minnesota the fishing opener and preparation for corn planting often coincide—that’s why you won’t see many crop farmers wetting lines on Leech Lake come May 10. That’d be akin to seeing tax accountants whooping it up at Mardis Gras in February. It turns out corn and fishing have another connection, and this one is a little more insidious. Research out of Indiana farm country shows that the caddisfly, a key link in many a freshwater stream food chain, may face a serious threat from genetically engineered corn. Ironically, soon after reading the study in the Proceedings of the National Academy of Sciences, I happened upon an Iowa Farmer Today cover story headlined: “Biotech crops may help environment.” The article went on to describe how the eco-angst that dogged GMO crops a few years ago may be a thing of the past. In light of the caddisfly study, that IFT headline may be a whole lot of wishful thinking.

The PNAS study, which was conducted by scientists from four Midwestern universities, took place on 12 headwater streams in northern Indiana, a place where 90 percent of the landscape is dominated by row crops (sound familiar?). What the researchers set out to do was measure the impact genetically engineered corn is having on aquatic ecosystems. Specifically, they were looking at corn that’s been engineered to produce the toxin Bacillus thuringiensis (Bt). Such corn is resistant to the European corn borer pest and it’s become quite popular in recent years, with at least 35 percent of the crop being the the Bt variety these days.

One problem with Bt is that it kills insects from the order lepidoptera, which includes moths and butterflies. That’s why there was so much concern several ago over the impact large plantings of Bt corn would have on monarch butterflies.

But no one has ever taken an extensive look at what happens when corn leaves, pollen, cobs and other field material make their way into streams and other aquatic systems via rain storms, snow melt and wind. That’s a pretty big oversight. After all, what makes Bt corn effective is that the toxin is ubiquitous throughout the plant, and that it stays there through rain, snow, sleet and the gloom of night. So when the corn borers munch on any part of the plant and in any conditions, they get a deadly dose. Caddisflies are close relatives of corn borers, and these aquatic insects live by feeding off byproducts such as pollen and corn leaves that find their way into the water.

Indeed, caddisflies in the Indiana streams studied commonly had pollen grains in their guts, and they were often found feeding on decomposing corn litter in the streams, according to the PNAS study.

Once they determined that caddisflies do feed on corn pollen and leaves, the scientists went to the laboratory, where they fed litter from Bt maize to the insects under controlled conditions. The result? In the case of the leaf-shredding caddisflies, eating Bt corn litter lowered their growth rate by more than half. They also found that when fed high concentrations of Bt pollen, 43 percent of algal-scraping caddisflies died.

“Lower growth rates and higher mortality of stream caddisflies, as measured in our laboratory feeding studies, could potentially reduce secondary production and consequently the prey biomass available to stream and riparian predators, such as fishes, amphibians, and birds,” concluded the scientists.

Later they wrote: “…headwater streams in the midwestern United States are already impaired by nutrient enrichment and extensive habitat degradation; Bt crop byproducts could represent an additional stressor to these systems, which has implications for stream restoration and riparian management in agricultural landscapes.”

That should make all you trout anglers quake in your waders. It should also worry anyone who cares about the basic building blocks of a healthy stream or river.

But let’s put things in perspective here. Since this is the first significant study of the effects of Bt corn on aquatic systems, it should be considered exactly that: the first of what hopefully will be many similar research endeavors. This is not a blanket indictment of genetic engineering, but it does raise red flags about one way it’s used: as a tool for inserting toxins into plants—toxins that stick around through thick and thin.

Unfortunately, not everyone sees it that way. It didn’t take long for plant scientists and genetic engineers to write letters to Proceedings attacking the Indiana study. One even went so far as to rip on PNAS itself, saying it had caused “significant damage” by publishing the paper. Damage to what? The anti-caddisfly lobby?

It should be noted that one of the authors of that particular letter is at the Donald Danforth Plant Science Center, which has as one of its “partners” good old Monsanto. Monsanto and other GMO giants are unusually thin-skinned when it comes to any questioning of genetic engineering. When a commission of more than 400 agricultural experts from around the world released a series of reports earlier this month that called for a major shift to farming systems that are more sustainable, absent from the press briefings were Syngenta and Monsanto, as well as other representatives of the biotechnology industry. In March, such firms pulled out of this unprecedented endeavor (it’s called the International Assessment of Agricultural Knowledge, Science and Technology for Development) to address food scarcity and environmental degradation, claiming the study was biased against genetically-modified crops.

In fact, according to the Worldwatch Institute, biotechnology is described in the final reports as offering “tremendous possibility” for improving productivity with products such as water-resistant crops. But concentrated ownership of biotechnology has limited the use of these crops in developing countries. For one thing, genetic engineers are developing crops that are not adapted to local conditions. This has long been a concern of independent plant breeders here in this country. The result is that genetic engineering is narrowing, not widening our germplasm, leaving fewer options for farmers who need local crops adapted to local conditions. This is becoming particularly critical as our weather patterns become increasingly unpredictable, showing extreme variances literally from one watershed to the next.

But the Monsantos of the world don’t want to hear that, as they strive for complete control of all “intellectual property rights” when it comes to seeds via the implanting of characteristics they have deemed “unique.” Handing over the very means of sustenance—germplasm—is hard for anyone to stomach. To gain such control means the GMO industry must propagate the myth that biotechnology, and only biotechnology, will save the world from starvation and general ruin. And so questioning anything about genetic engineering makes you anti-scientific, anti-farmer, even anti-human.

Genetic engineering of farm crops really hit its stride after the mid-1990s, thanks in large part to a federal government that was willing to serve as an enthusiastic—often blindly enthusiastic—promoter of all the “promise” a GMO future held. During much of Dan Glickman’s tenure as U.S. Secretary of Agriculture under President Bill Clinton, he pretty much repeated the agribusiness mantra that genetic engineering was needed to feed the world and keep American farmers competitive.

But right after he left office, Glickman dropped a bit of a bombshell. In a 2001 interview with the St. Louis Post-Dispatch, the former secretary sharply criticized the pressure that was put on USDA by pro-biotech forces.

“What I saw generically on the pro-biotech side was the attitude that the technology was good and that it was almost immoral to say that it wasn’t good because it was going to solve the problems of the human race and feed the hungry and clothe the naked,” Glickman told the newspaper. “And there was a lot of money that had been invested in this, and if you’re against it, you’re Luddites, you’re stupid.”

Glickman continued: “There was rhetoric like that even here in this department. You felt like you were almost alien, disloyal, by trying to present an open-minded view on some of the issues being raised. So I pretty much spouted the rhetoric that everybody else around here spouted; it was written into my speeches.”

I think now we know who suffers “significant damage” when one little study on winged fish food is conducted in corn country.

By the way, that same Iowa Farmer Today article on how genetically engineered crops like herbicide-resistant soybeans help the environment also included an interesting sidebar: an article on how herbicide-resistant super weeds are requiring increased applications of residual (read: they stick around awhile in the soil) herbicides. But then, that article wasn’t on the cover.

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