Genetically modified crops and the environment

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Genetically modified crops and the environment

• Dr Brian Johnson
• Biotechnology Advisory Unit

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Biotechnology Advisory Unit

• Lead Agency on GM issue representing statutory
  conservation organisations in Britain
• Provides advice to central and local govt, the
  public and the media
• Only deals with impacts on biodiversity and
  countryside, not food and feed safety or human
  health

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Philosophical Point!

• Why oppose a technology?
• Because it is dangerous!

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So ban mechanical engineering!
Dangerous because

• The technology is very risky
• Some risks are unknowable
• It can kill or injure people
• Multinationals profit from it
• It is in the hands of rogue states

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Technologies are neutral
Real Issues What do we do with technologies?
When do we do it? How much do we need to
know? How do we recognise risks and benefits?
Who makes decisions and how? Do we need ethical
codes?
So what do we do with new technologies in
agriculture? We use them with little regard for
the consequences!
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Agriculture degrades physical resources

• 40 of worlds agricultural soil is now seriously
  degraded. An area of 2 billion ha larger than
  the US and Mexico combined
• Soil degradation has a significant adverse effect
  on productivity of 16 of world agricultural land
• Irrigation is increasing and water supply
  decreasing. Aquifers are lowering in
  agricultural areas. Rivers are drying up.

Source World Resources Institute Washington DC
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Agriculture Degrades Natural Systems

• Land take destroys natural forests, wetlands and
  grasslands Intensification damages biodiversity
  in farmed landscapes
• Agriculture pollutes water ploughing and
  chemicals
• Overgrazing, irrigation and arable production is
  turning productive land to desert even in North
• Most damage has been done by non-chemical
  agriculture but is accelerated by agrochemical
  use
• Limit to available arable soil area

We may need more food but not more of the same
agriculture
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UK Government Quality of Life Indicator Bird
Populations
Source British Trust for Ornithology surveys
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We need food, but different agriculture

• There should be much more intelligent ways to
  farm
• Modern organic systems
• No-till systems
• Agrochemicals with low environmental impacts
• Crops that defend themselves
• Crops adapted to the land not vice versa
• Crops that make their own nitrogen like clover
• Perennial crops replacing annuals
• Can we do all this using conventional crops?
• Can novel crops help? Could transgenic technology
  help?

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Is Biotechnology safe?

• Mutational breeding that changes hundreds of
  genes has been used for 70 years without serious
  problems
• European regulatory system for health and safety
  is rigorous for transgenic organisms
• GM crops that get to market appear to be as
  stable as those from other sources
• BUT there are unanswered questions about possible
  environmental risks from some GM crops

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The risks are different

• Putting genes from other organisms into new
  plants is relatively new
• GM traits are sometimes unachievable by
  conventional breeding
• Different risk does not mean bigger risk!

We need to understand risks and to be able to
assess them
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Risks from novel crops

• Direct Risks
• Toxicity to humans, livestock and wildlife
• Gene flow to other crops, wild relatives
• Gene stacking

• Indirect Risks
• Changes in management practices
• Changes in patterns of land use

Must be viewed in the context of risks from what
we do now
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Science Review - risks

• Environmental impacts of each GM crop should be
  fully assessed prior to commercial release
• Jury is still out on environmental impact of GMHT
  crops, pending further scientific study
• Need to better understand impacts of gene flow
  from GM crops to other crops and to wild
  relatives
• Gene stacking identified as an area that needs
  more study
• No merit in making generalised statements about
  the impacts of GM crops

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How can we assess risks?

• Some can be assessed theoretically then
  monitored to confirm
• Some may mean doing more science so we need time
• Need for good science done safely very strict
  controls and independent scrutiny
• Field scale trials may be needed

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Farm Scale Evaluations worlds biggest and best
study
Compared effects on biodiversity of how farmers
use herbicides in GM and conventional winter and
spring oil seed rape, maize and beet (sugar and
fodder)
Focussed on the impact on abundance and diversity
of farmland-dependent wildlife
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The results

• If GMHT oilseed rape and beet were grown on a
  large scale there would be further reductions in
  wildlife in fields
• GMHT maize could give some benefits for
  biodiversity
• Results were very clear and conclusive for these
  crops under this management

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Recent research on GM crops

• Seeds may be more important than pollen in gene
  flow to wild relatives
• Pollen will move over long distances (OSR)
• Hybrids between OSR and wild turnip are
  widespread
• Bt wild sunflowers have increased fitness, but
  fungal-resistant sunflowers do not
• GMHT beet can be managed to allow weeds to
  persist longer, but seed banks will be rapidly
  depleted and there is no benefit for birds

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So what does it all mean?

• Each GM crop has different impacts on the
  environment
• Technology is a red herring you can get similar
  environmental impacts from conventionally bred
  crops
• Not all impacts are damaging some GM crops may
  much better for the environment so if GM-free
  zones are established these could not be used
• Genes move but does that matter? Sometimes it
  might but often it will not we dont know yet!
• Containment using separation distances will
  not work for all crops
• The regulatory system works some crops get
  limited consent but some are banned!