ISIS Report 16/12/05
GM Contamination Accelerating
No Co-Existence Possible
Untried and untested GM crops are out of the bottle even in the UK
where no GM crops are commercially grown. Rhea Gala
A fully referenced
version of this article is posted on ISIS members’ website. Details here
GM crops, the vast majority engineered for just two traits - herbicide
tolerance and Bt pesticide, or stacked with both - have been released on five
continents for up to nine years, causing widespread contamination of food,
feed, seed and the environment across the globe.
Genetically modified DNA from any part of a GM plant can enter the environment
unobserved, for example, through pollen transfer to a conventional crop, through
seed dispersal or plant decomposition and persistence in soil ecology. The
toxins encoded in the DNA also kill wildlife and contaminate soil and water,
as do herbicides such as glyphosate and glufosinate ammonium that are an essential
component of the herbicide tolerant crop system.
Outcrossing
between a GM crop plant and a wild relative and over dependence of the GM
crop on herbicides to which the crop is tolerant, are causing a wave of “superweeds”
to emerge in the US and elsewhere; the UK has reported a potential candidate
earlier this year.
UK’s herbicide tolerant weed hybrids
The UK government reported genetically modified herbicide tolerant
(GMHT) hybrid weed seedlings at field trial sites earlier this year. One was
a cross between Bayer’s GMHT oilseed rape (Brassica napus) and its
distant relative the common arable weed, charlock (Sinapis arvensis),
and two were hybrids of Brassica napus and B. rapa.
The findings, which were not announced, were nevertheless widely reported and
somewhat exaggerated in the press [1] because many politicians and government
scientists had repeatedly downplayed the possibility of GM gene transfer to
wild relatives, the emergence of GM superweeds, or any other adverse effects
of GM crops. For example, in 2000 the EU Environment agency concluded, “ There
appears to be general agreement that natural gene flow is not likely to occur
between B. napus and S. arvensis”. The EU has an industry-sponsored forward
plan for ‘coexistence’ in European countries for GM, conventional and organic
crops to 2025 (“Beware the New Biotech Eurovision” SiS
24).
The report to DEFRA from the Centre for Ecology and Hydrology, Dorset, found
that [2], “The commercial growing of genetically modified, herbicide-tolerant
oilseed rape is seen to result in the potential for the inserted gene to escape
from the crop and become incorporated in the genomes of one or more related
wild crucifer species, potentially giving a competitive advantage to the recipients.”
The “virtually impossible” already happened
The emergence of
two GMHT B. napus and B. rapa hybrids was inevitable
as B. rapa is a parent of the commercial variety B. napus and
spontaneous hybrids are well known to occur. Although the two plants generally
do not share the same distribution, B. rapa may be overlooked because
of its similarity to feral oilseed rape. The finding of these hybrids and
the GMHT charlock hybrid show that the difficulties of coexistence between
GM and conventional crops will be insuperable. Despite that, the authors
still concluded, “The risks of transfer of herbicide tolerance to wild relatives
of oilseed rape appear to be minimal.” But Dr Brian Johnson, an ecological
geneticist and head of the Biotech Advisory Unit at English Nature, said that
the charlock superweed would be fertile through its pollen to neighbouring
plants [1]; and that charlock seeds can remain in the soil for 20 to 30 years
before they germinate.
Huge problems of cross-contamination and herbicide resistance have arisen
in countries like Canada and the US (see for example “GM sugar beet turned sour”,
SiS
25; “Roundup Ready sudden death”, SiS28).
Herbicide tolerant volunteers
Herbicide tolerant volunteers were found in the two years following the Farm
Scale Evaluations, and they tend to persist, requiring control with toxic herbicides
other than glufosinate ammonium. The authors thought that volunteers may pose
a greater risk for gene flow of the bar gene into the environment, than
hybridization with wild relatives, especially if the same gene construct is
introduced into other crop species. They also pointed out that these problems
“highlight implications for the EU threshold limits of GM content in oilseed
rape crops set at 0.1 percent, 0.3 percent and 0.9 percent for organic seed,
certified seed and food & feed, respectively” [2].
GM contamination lasts at least 15 years in soil
The BRIGHT report [3] on a study in the UK begun
in 1998 with funding from Monsanto, Bayer CropScience, BASF, and Agrovista
UK Ltd, among others, tried to underplay problems to wildlife from GM crops;
but found that when HTGM sugar beet followed HTGM winter oilseed rape, additional
herbicides were needed to control volunteer rape.
There were also problems
with crossbreeding between herbicide tolerant varieties of rape, producing
seeds resistant to more than one herbicide, and making management of minimal
herbicide regimes very tricky even for experienced practitioners.
The authors of
BRIGHT have since looked further into the problem of persistence of GM seeds
in seedbanks in a new study on the population dynamics of volunteer
rape, Brassica napus, comparing two GMHT winter oilseed rape cultivars
and two conventional cultivars [4].
They found that seed remaining in the field after
harvest averaged 3 575 seeds per square metre but ranged from less than 2
000 up to more than 10 000 seeds. There was a rapid decline in seed number
during the first few months after harvest; a mean loss of 60 percent of seeds
thought to be removed by wildlife. But in subsequent seasons, the seedbank
declined much more slowly at four of the five sites, at about 20 percent per
year. The models predicted a 95 percent seed loss after approximately nine
years, resulting in nearly 200 seeds per square metre, which would give rise
to at least two HT rape volunteers nine years after the original crop was
sown. This predicts the emergence of an average of one plant per square metre
after 15 years.
Although there was no difference between the
four cultivars in either the number of seeds shed at harvest or in their subsequent
persistence, the importance of the persistence of GM rape seeds, simply in
the context of the coexistence of GM and non-GM crops is a clear cause for
concern. The researchers concluded that the density of more than two volunteers
per square metre would exceed the European Union threshold of 0.9 percent
adventitious presence of GM seeds in a non-GM crop, if the subsequent crop
were conventional.
These results
come in the same week as DEFRA’s report showing that the harmful effects on
wildlife from GMHT crops in the Farm Scale Evaluations (see “GM crop fails
final test” SiS 26) persist for at least two years
[5]. Results
showed that weed seedbanks following GMHT spring oilseed rape
were significantly lower than following conventional crops over this period
as was the case with winter oilseed rape [6]. Seedbanks following GMHT beet
were also smaller providing empirical evidence for longer-term effects of
GMHT cropping on farmland biodiversity [5]. Seedbanks for GMHT maize were
higher than conventional, mostly probably due to the use of the now banned
herbicide atrazine on the conventional crop.
Illegal contamination with GM material
These cases of environmental contamination with GM material have been detected
in the UK where there is as yet no commercial planting of GM crops; emphasising
that contamination in countries such as Canada, the US and Argentina - where
GM monocultures are becoming, or are already the norm – is far more extensive
(“Soya disaster in Latin America”, SiS28).
Though hardly reported in the mainstream press,
well over 60 incidents of illegal or unlabelled GM contamination have been
documented in 27 countries on five continents; eight of which occurred in
the UK. And those are only the recorded incidents [7]. The worst single contamination incident
was of StarLink Maize, a GM variety approved only for animal feed which entered
the human food chain in seven countries, the US, Canada, Egypt, Bolivia, Nicaragua, Japan and South Korea.
Moreover GM DNA is in the European human food chain via GM animal feed (“DNA
in food and feed” SiS
23), but milk and meat are not labelled as such, and are considered safe
by the UK Food Standards Agency.
Recent GM contamination in Europe
UK Member of Parliament Michael Meacher recently condemned seven years of secrecy
over GM food and feed safety [8]. “On the seventh anniversary of the first
disclosure of scientific concern about GM food safety I am supporting calls
for freedom of access to the data used by the Government to approve GM foods.”
Meacher said, “ Since the issue is the launching of GM products into the nation’s
food supply that have never been independently tested, this is a public scandal
of huge proportions.”
Next year the EU will decide how member countries
will draft ‘coexistence laws’ for GM, conventional and organic crops to be
grown together. But at a conference in Bologna, Italy, in September,
experts maintained such ‘co-existence’ to be biologically impossible. Angelika
Hilbeck of the Swiss Federal Institute of Technology Zurich said that [9],
“[trying to prevent GMO contamination] starts with the seeds; you want to
make sure you get uncontaminated seeds. This is the origin of everything,
from there on the contamination multiplies. For example, in Canada it is
hardly possible to get GM-free canola seeds.”
News emerged in October about Monsanto’s massive
illegal GM contamination of Romania. The country has the largest GM
cultivated landscape in Europe; officially half the 140 000 hectares of soya
planted in 2005 is registered to be GM. However, according to representatives
of farmers’ associations and even biotech giant Monsanto’s former Romanian
manager, up to 90 percent of soya is GM. The core of the problem is due to
genetically engineered crops contaminating the traditional cultures, as well
as the illegal selling of GM soya seeds. GM potatoes and plums were also
found [10].
Greenpeace protesters stopped
the 125 000 tonne bulk-carrier Étoile’s huge consignment of GM animal
feed from the US from being unloaded in Bristol. The feed was destined for British dairy cows to produce milk
for the UK’s biggest supermarkets. Sainsbury's, Tesco, Asda, Waitrose and Morrisons
all sell own-brand milk from cows fed on American GM feed. The GM
varieties were banned in Europe, but were found by expert laboratory analysts in samples taken from ships over
the last two years.
Campaigners believe that only
strict rules with liability regulations applied by governments can stop the
unauthorised spread of GM seeds and products, which seems to be increasingly
out of control all around the world. Doreen Stabinsky of Greenpeace International
says, “If states do not act and set strict rules now GM crops will further
contaminate lands, seeds and food around the world.” But no Government or
international agency has established a public record of contamination incidents
or other problems associated with GM crops. GeneWatch UK and Greenpeace International are launching the first on-line register of genetically
modified contamination incidents. The on-line, searchable web site gives details
of all the known cases of GM contamination of food, feed, seed and wild plants
that have taken place worldwide [11].
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