The world’s biggest study on the impact of genetically modified crops on wildlife found birds and bees are more likely to thrive in fields of natural rapeseed than modified seed but the difference is not due to genetic engineering, scientists said Monday.
The scientists behind the British study were keen to stress the differences between the two arose not because the crop was genetically engineered but because of the way pesticides were applied.
“The study demonstrates the important of the effects of herbicide management on wildlife in fields and adjacent areas,” researcher David Bohan said.
Engineered, or genetically modified, crops "give farmers new options for weed control. That is, they use different herbicides and apply them differently," the scientists wrote in their report summary.
"The results of this study suggest that growing such GM crops could have implications for wider farmland biodiversity," they added. "However, other issues will affect the medium- and long-term impacts, such as the areas and distribution of land involved, how the land is cultivated and how crop rotations are managed. These make it hard for researchers to predict the medium- and large-scale effects of GM cropping with certainty."
The trial was the last in a four-part, $9.5 million test.
Fewer broad-leaf weeds
Scientists said that when compared with conventional winter-sown rapeseed, the engineered, herbicide-resistant plants kept the same number of weeds overall but fewer broad-leaf weeds and more grassy ones.
Flowers of broad-leaf weeds provide food for insects, while their seeds are an important food source for other wildlife.
Researchers said that while fields planted with the biotech version were found to have fewer butterflies and bees, differences arose not because the crop was genetically-changed but because of the way they were sprayed.
In October 2003, the same government trials found that engineered sugar beet spraying was significantly more damaging to the environment than the management of conventional varieties.
They also concluded that gene-spliced, spring-sown rapeseed may also have a negative impact on wildlife, while engineered feed corn did not.
Industry, activists react
The biotech lobby insist the crops are safe.
“GM crops offer a better, more flexible weed management option for farmers and, as the results today indicate, the difference between the impact of growing GM and non-GM crops on biodiversity is minimal,” said Tony Combes, deputy chairman of the Agricultural Biotechnology Council, which represents biotech firms like Monsanto and Syngenta.
Green groups, however, were aghast.
“These results are yet another major blow to the biotech industry. Growing GM winter oilseed rape would have a negative impact on farmland wildlife,” Friends of the Earth campaigner Clare Oxborrow said.
Despite optimism from proponents of the technology, and the fact that the United States has embraced it, engineered crops seem a long way off in Britain.
Last year, the only firm to win approval to grow a genetically modified crop in Britain -- Germany’s Bayer CropScience -- abandoned field testing in Britain. It also withdrew any outstanding applications awaiting government approval to sell biotech seeds.
As a result, no new engineered seeds are awaiting approval in Britain, whereas in the mid-1990s more than 50 different engineered seeds were.
