NAFTA report: Spread of GM maize in Mexico

Only ground maize to be imported as a precaution

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Three years ago an article published in the prestigious journal Nature sparked intense scientific and political debate. Two Californian scientists claimed to have discovered that genetically modified maize had spread to Mexican maize varieties. At the time, there were serious misgivings about their methods of analysis and conclusions. The North American Free Trade Association (NAFTA) appointed a commission to conduct a scientific examination of the issues raised and to make recommendations for further action. The final report has now been published: it recommends importing GM maize only in the form of ground maize as a precaution. Mexico is a centre of biodiversity for maize.

The report from the Commission for Environmental Cooperation (CEC) of the North American Free Trade Association (NAFTA), which up until now was only published in draft form, assumes that transgenes from imported genetically modified US maize have spread to Mexican maize varieties. Since it is not yet possible to tell whether this poses a threat to the biodiversity of native maize varieties, the authors recommend importing only ground maize from the USA and refraining from release trials and the cultivation of GM maize in Mexico for the time being. Slow road to publication  The NAFTA report Maize and biodiversity: Effects of genetically modified maize in Mexico was intended for publication in June. No official reasons have yet been given for the delay. However, the environmental organisation Greenpeace suspects that the US government attempted to delay publication of the report and its recommendations. Since mid-September the NAFTA report has been scrutinised by the governments of Mexico, Canada and the USA. They have sixty days to decide whether the report will be published at all. US and Canadian government representatives cast doubt on the scientific validity of the report. The spokesman for the American Environmental Protection Agency (EPA), Richard Hood, said they wanted to be sure that all recommendations in the report could be substantiated scientifically

Threat to biodiversity?

Mexico is regarded as the birthplace of cultivated maize. There are countless local varieties here with vast genetic diversity. Since the scientific journal Nature first reported the spread of foreign genes from GMO maize to Mexican maize varieties in November 2001, there has been much debate about the scale of the problem and its consequences. Some believe that the outcrossing of transgenes poses a serious threat to the genetic diversity of Mexican maize varieties, whilst for others the spreading and mixing of cultivated and local varieties is nothing unusual. For this group, whether genes from conventional high-performance or transgenic varieties can become permanently established in local varieties and so reduce biodiversity depends primarily on whether they confer a selective advantage to the progeny. Even if transgenes did become established in the gene pool of Mexican maize varieties, this would not necessarily imply a threat to biodiversity.

Commission: Transgenes have spread

The fifteen members of the CEC were assigned the task of assessing the biological and socio-economic impact of a potential spread of transgenes in Mexico. To involve both experts and the general public from the region in the evaluation process, the commission organised a symposium entitled “Maize and Biodiversity” in March this year in Oaxaca, the centre of Mexico’s maize cultivation.

It was here that the Mexican government presented the first official figures on the scale of the spread of transgenes. During tests conducted in 2001 in 188 communes in the Oaxaca region, 7.6 percent of the maize plants examined were found to contain foreign genes from GM maize. During subsequent investigations this figure fell to 0.11 percent. There is no information available yet for 2003 and 2004.

No GM maize as a precaution

The report produced by the CEC for NAFTA is also unable to state for certain whether the spread of transgenic material could threaten the genetic diversity of Mexican maize. It is not yet known to what extent transgenes have already spread and how effectively they are passed on to the next generation of plants. Neither is it clear how well the US maize varieties can reproduce under the climatic conditions found in Mexico.

The report nevertheless recommends that Mexico import only ground maize from the USA, since this cannot be propagated. In addition Mexico should not authorise any commercial cultivation or release trials of GM maize. The chairman of the CEC, Jose Sarukhan, explained that Mexico should apply the precautionary principle with regard to GM maize.

The USA exports six million tons of maize annually to Mexico, the majority of which is used for animal feed. GM maize varieties account for 45 percent of US maize production. Although the cultivation of GM maize is banned in Mexico, many small-scale farmers use imported maize grains as seed for their own cultivation. This appears to be the most likely cause of the spread of transgenes in Mexico.

 

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