New report questions scientific validity of UK GM crop trials

Brussels, Mar 2003

The farm scale evaluations of genetically modified (GM) crops in the UK are complete, but before any final data have been published, campaigners are already calling into question the validity of the results.

The four year experiment, the largest of its kind in the world, and sponsored by the UK government, seeks to establish whether or not the broad-spectrum herbicides used with many GM varieties would harm farmland biodiversity.

The trials involved growing GM and conventional crops of oil seed rape, maize and sugar beet in adjacent fields. Scientists regularly counted weeds, insects and other biodiversity indicators in each of the fields in order to discover whether GM crops held significantly more or less wildlife than their conventional neighbours.

The experiment was designed to be able to accurately detect a 1.5 fold difference in biodiversity indicators between fields, but opponents of the trials claim that certain key indicators are likely to vary naturally by far more than the 50 per cent margin allowed for in the tests.

Friends of the Earth (FoE), a leading anti-GM campaigner, has produced an analysis, published in the New Scientist on 26 March, which claims that the experiment will 'fail to provide any conclusive evidence on whether GM crops will do long-term harm to farmland wildlife'.

FoE real food and farming campaigner Pete Riley, whose team compiled the analysis, explains: 'We have published this report because we think it is vital that the public, farmers and the government realise the limitations of the farm scale evaluation results.'

Other potential flaws in the experiment's methodology highlighted in the report include the failure of researchers to monitor important soil organisms due to money and time constraints, and concerns that the herbicides used were selected on the basis that they maximise biodiversity rather than produce a good yield, rendering the results meaningless.

As for the reasons behind these inconsistencies, Mr Riley believes that 'The [UK] Government was not interested in properly investigating the long term impacts of GM crops, it wanted to avoid the threat of a moratorium. [...] This is not the fault of the researchers - their hands were tied.'

Les Firbank from the Institute of Terrestrial Ecology in Cumbria, the coordinator of the trials, described claims that the experiments were statistically flawed as 'speculation'. He said that no-one could comment on the validity of the trials until the data are published.

Peter Green, president of the Royal Statistical Society, says that while many of the statistical issues raised in the report are valid concerns, such problems are relatively common and well-established methods for dealing with them do exist.

'The danger with an issue that is so highly charged politically is that some people will seek black and white answers when they are not attainable,' says Mr Green.

To read the FoE report, please consult the following web address:
http://www.foe.co.uk/resource/reports/sc ience_smokescreen.pdf

For further information, visit:
http://www.newscientist.com/news/news.js p?id=ns99993547

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