The risks to the environment resulting from releases of genetically modified organisms will be
analogous to the risk from release of classical biological control agents, or to the release of novel
organisms to a new environment. Many of the same ecological, cultural, political and economic
pressures will be present.
Risk assessment where release into the environment is projected is totally different from that for
contained use. The wide nature of the environment is such as to make it extremely difficult to
produce a 'flow-scheme' for an assessment of risk. What almost all countries have done is to
produce a series of questions regarding the organism, vectors and predecessors and the site into
which it is to be released. These questions allow a case-by-case estimate of risk, based largely on
familiarity with the organism, the host, donor and vector.
In many cases, particularly with the release of genetically modified plants, microbes for
bioremediation or animals, the major difference is that the modified organism has been designed
to survive in the environment, and in particular circumstances has been designed to be fitter for
the environment than the wild-type. Examples might be heat-or cold tolerance, drought or
saline-tolerance in plants, and tolerance to heavy metals or organic chemicals for both plants and
microbes. If a fish is given a growth hormone gene to enable faster growth during early life, it
may remove all food for other fish which develop more slowly and be more fitted to its new
environment than the traditional fish. This implies many different approaches to risk assessment
than that used for contained use.
There is much information about the effects of releases (of both modified and natural). Several
'lessons' have been identified
- Negative environmental effects may result from the release of novel genetically modified
organisms or natural organisms
- To adequately document the negative impacts, appropriate questions need to be asked and
trials designed to answer them
- Self-dispersing organisms will find their way to suitable available habitats and will not
stay within the prescribed area without management
- Self-reproducing organisms and certain long-lived ones may affect ecosystems at many
levels and in direct and indirect ways far into the future. Therefore, modified organisms
should be created which cannot establish wild populations, or if establishment is desired,
then extra precautions need be considered
- Extinction of non-target species are probable, but by recognizing vulnerable species early,
many of these extinctions may be prevented. Vulnerable species should be monitored.
- The use or dispersal of organisms for short-term benefit will be attempted. Extra
precautions, security and enforcement will be needed.
The assessment of risk may well be different for crop plants released into the agricultural
environment, and for microbial products which are released into the more general environment,
or even where they are released into a polluted environment where the organism has been
modified to use one of the pollutants as its sole carbon source. Many believe that risk
assessments do not provide sufficient assurance to allow the release of genetically modified fish.