GeneWatch PR: New Study Overturns Claimed Wildlife Benefits of GM Crops

Tuesday 15th March 2005

Today, in advance of the announcement of the final results of the Farm-scale Evaluations (FSE) of GM winter oilseed rape next Monday (21st March 2005), GeneWatch UK, the Five Year Freeze and Friends of the Earth, jointly published two key documents:

  1. A Q&A on the FSE results which are to be announced next week. This highlights the key issues and sets the context for the outcome of the trials. It can be read at:
  2. A new report ‘An analysis of the findings of the BRIGHT trials with GM herbicide tolerant crops in relation to environmental impact’, which overturns the biotech industry claim that the GM crops in the BRIGHT trials, published last November, showed wildlife benefits. The report can be accessed at The press release is below.

For more information please contact;

Sue Mayer (GeneWatch UK) on 01298 871898

Pete Riley (Five Year Freeze) on 07903 341065

or Clare Oxborrow (Friends of the Earth) on 020 7566 1716.


A new, report ‘An analysis of the findings of the BRIGHT trials with GM herbicide tolerant crops in relation to environmental impact’ published today, undermines claims that a four year research project into the growing of GM crops (the BRIGHT trials) showed that they were not harmful to farmland wildlife [1]. The study, conducted for GeneWatch UK, the Five Year Freeze and Friends of the Earth by the Initiative on Organic Research, reveals that the design of the BRIGHT trials meant that environmental impacts could not be properly investigated (executive summary below).

When the findings of the BRIGHT trials were published in November 2004 [2], the industry body, the Agriculture Biotechnology Council, commented that "We believe this report buries the myth that these two GM crops pose any new problems for farming or the environment". [3] Mirroring the industry’s interpretation, there were media claims that: "Study finds benefits in GM crops. GM crops are no more harmful to the environment than conventional plant varieties, a major UK study has found" (BBC on 29th November 2004) [4].

However, this new analysis of the BRIGHT trials for GeneWatch, the Five Year Freeze and Friends of the Earth, shows that the media and public were misled. It concludes that:

"…while the experimental design is adequate for carrying out a basic herbicide evaluation trial within an arable rotation, there is insufficient replication to determine effects on biodiversity in what is very a varied environment’".


"To fully answer the trial objectives in relation to understanding the environmental effects of GMHT crops was impossible with the level of funding and experimental design. Environmental (botanical) impacts could not be extensively investigated in the trials which were designed to meet a primarily agronomic objective."

The report concluded that in the BRIGHT trials:

The only environmental measurements made during the trials were weed seed-bank size and species. There were no measurements of invertebrates, soil microflora, gene flow to wild species, or field margin effects.

The environmental measurements were inconclusive. Because insufficient samples of weed seeds were taken at each sampling event, and they were not take frequently enough during the rotation, it is not possible to draw firm conclusions about the changes in the composition of the weed seed-banks, or the impact of these changes in terms of biodiversity.

In addition, the new analysis by the Initiative on Organic Research highlights that some of the findings of the BRIGHT trials actually suggest that there could be long-term problems with growing GM herbicide tolerant beet and oilseed rape:

The trials showed that some important weeds are not properly controlled by the herbicides used with GMHT crops, so farmers would need to increase use of more toxic herbicides to control them.

Gene flow from GM to non-GM oilseed rape and gene stacking (where more than one GM trait is acquired), was shown to be a real risk.

The BRIGHT trials found ‘volunteer’ GM oilseed rape plants persisting in following crops, and these could act as a source of future GM contamination.

GeneWatch Director, Dr Sue Mayer said:

"The biotech industry was more interested in spinning the results to sound good than in presenting an honest picture of the findings. This approach will not build public confidence in their products."

Director of the Five Year Freeze. Pete Riley said:

"Although the BRIGHT project did provide a lot of new information, claims that GM crops do not harm wildlife simply cannot be justified by the results – the experiment was not designed to investigate this to the level required to draw such conclusions. These results do not provide the basis for predicting the long-term impact GM crops on the wildlife remaining in arable fields."

Friends of the Earth’s GM Campaigner, Clare Oxborrow said:

"This new report shows, once again, that the biotech industry will clutch at any straw. But the BRIGHT trials are not the good news about GM crops that the industry claimed; it’s time they stop spinning and start listening to public, who have made their rejection of GM crops and food clear."

Notes to editors:

  1. Turner, R.J., Bond, W. & Pearce, B.D. (2005) An analysis of the findings of the BRIGHT trials with GM herbicide tolerant crops in relation to environmental impact. A report for GeneWatch UK, the Five Year Freeze and Friends of the Earth. Available at:
  2. The BRIGHT (Botanical and Rotational Implications of Genetically modified Herbicide Tolerance) project was set up to investigate the growing of GM oilseed rape and sugar beet in a rotation with winter cereal crops from 1998 to 2003. It was funded jointly by the government and the industry. The report was published on 29th November 2004: Sweet J, Simpson E, Law J, Lutman P, Berry K, Payne R, Champion G, May M, Walker K, Wightman P, Lainsbury M (2004). Botanical and rotational implications of genetically modified herbicide tolerance in winter oilseed rape and sugar beet (BRIGHT Project). Project Report No. 353. HGCA. Available on
  3. Agriculture Biotechnology Council Press Release 29th November 2004. BRIGHT puts the spotlight on GM benefits.
  4. Available at:

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