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NAFTA study: Transgenic corn threatens Mexico's native species

(Saturday, March 13, 2004 -- CropChoice news) -- Associated Press, 03/12/04: OAXACA, Mexico- If left unchecked, modified genes spread by imported U.S. biotech corn threaten to displace or contaminate native varieties in Mexico, the birthplace of corn, a NAFTA watchdog panel said.

The study for the Commission for Environmental Cooperation said gene transfers could damage Mexico's vast storehouse of native corn, whose wild ancestral genes might one day be needed to help commercial crops overcome diseases or adverse conditions.

The report, presented Thursday at a symposium in Oaxaca, is still in draft form and must be approved during a June meeting of the commission, which consists of the top government environment officials of Mexico, the United States and Canada.

The study does not provide data on the prevalence of genetically modified corn in the Mexican countryside. But Amanda Galvez, head of Mexico's interagency group on biosafety and genetically modified organisms, said studies by her government found instances of gene transfer.

In 1998, Mexico declared a moratorium on genetically modified corn, making it illegal to grow except at licensed laboratories. Still, in a study of 188 corn-growing communities across Oaxaca state, 7.6 percent of plants tested positive for genetic modification in 2001, Galvez said.

She said officials warned farmers about the possibility they were planting genetically modified seeds, helping reduce the number of plants testing positive to 0.11 percent in follow-up studies. But the rate of unaffected plants will never drop to zero, she said.

"We can try to reduce the penetration of these plants, but we can't go back and stop their spread now," Galvez said.

The commission's report said gene transfer so far has been "insignificant from a biological point of view." But it added that the uncontrolled spread of genetically modified corn could one day make it impossible to find corn not manipulated by science.

"We don't know to what extent these genetically modified plants could just take over and cause other species of corn to die off," said Chantal Line Carpentier, the report's coordinator.

Gene migration is a hotly debated topic. Some scientists say it has not yet been proven to occur in corn. Others maintain that any negative characteristics caused by gene splicing will cause modified plants to die before they can reproduce, and say that positive effects will help native species survive.

About 40 percent of U.S. corn is genetically engineered with a bacterium's gene to ward off bugs without the use of pesticides, and Galvez said that gene was found in the Mexican government study.

A study published last month by the Union of Concerned Scientists said some unmodified corn, soy and canola seeds in the United States have been cross-pollinated by genetically engineered crops.

Farmers in Mexico first bred modern corn 6,000 to 8,000 years ago. The country is home to at least 59 species of maize, from the protein-rich variety used to make tortilla chips to a softer grain mashed for use in tamales.

Corn was born when farmers began crossbreeding teosinte, a plant with a jumble of sharp leaves that look like corn stalks but grow out instead of up. Teosinte is still found in Mexican fields, but is considered a weed.

Due in part to the North American Free Trade Agreement, 70 percent of Mexico's corn _ some 5 million tons a year _ is now imported from the United States, and 30 percent to 50 percent is genetically modified. While much of the imported corn is intended for use as animal feed, some has been planted and its pollen spread.

"The government aid program to food-depressed areas is the most likely culprit for disseminating genetically modified maize," the commission's report said.

Olga Toro's farm in the mountains of northern Oaxaca was the first place in Mexico where scientists detected genetically modified corn growing in the wild.

A 2001 study about alleged cross-pollination in Toro's five-acre plot and elsewhere in Oaxaca was published in the journal Nature. But the magazine later retracted the report, saying the researchers had not proven conclusively that contamination occurred. Its results are still being debated, but it prompted the later Mexican government study that also found contamination.

Toro said she unknowingly planted modified corn she received from a local food bank. The result was plants that shot up to heights two to three times normal, produced double the amount of corn and grew with almost no water. But she won't plant them again.

"They modified the genes and we got plants that lasted only one season," said the 43-year-old mother of six. "Regular plants last longer without help from anyone."

On the Net:

Commission for Environmental Cooperation, http://www.cec.org