gene flow and its possible consequences
• non-target species and biodiversity impacts
• resistance risk assessment and management
• transgene expression and locus structure
• problem formulation and options assessment
• useful links to scientific resources
|Non-target species and biodiversity impacts|
In the agricultural and natural environments, GM crops and their transgene products will come into contact with hundreds of non-target species with important ecological functions.
How do you assess risks to such species and to biodiversity in your environment? Which species and ecological processes are most at risk?
There are too many species to assess all potential effects individually. It is essential to evaluate, rank and select the species and ecological processes to identify those possibly most affected by the GM crop for further assessment.
Step 1. Identifying Ecological Functional
Groups. Species and ecological processes can be divided into ecological
functional groups – such as predators, pollinators and decomposers
– that relate to possible environmental risks. Some of these may
Species or ecological processes are classified to the groups. Each identified ecological functional group is analyzed separately in Step 2.
Step 2. Association with Target Crop and Significance. In each functional group from Step 1, all relevant species and ecological processes associated with the target crop in your country are ranked for their importance.
- how closely associated is the species or ecological
process with the crop?
Important species and ecological processes are retained for further analysis in Step 3.
Step 3. Exposure to GM Product: Preliminary Assessment. For the retained species and ecological processes, how likely is contact between these and the transgenic products produced by the GM plant?
What other ecological impacts on these species or processes
This will reduce the number of species and processes to a manageable number all of which are more likely to be associated with a risk than those not retained.
These three steps analyze and synthesize existing information, using local expertise. This helps to identify and prioritize key knowledge gaps in biodiversity at the region or country level.
Step 4. Retained species and ecological processes can be specifically tested for an actual effect on them that may represent a possible risk. It is important to use methods that are relevant to the biology and food webs of the species or ecological process in their crop environment.
The results of these analyses lead to the description of possible hazard pathways. We develop a relevant hypothesis for each pathway, and experiments to test each of them. In some cases, one simple experiment may answer the hypothesis and confirm or refute a possible risk; in other cases a series of experiments may be necessary. We suggest experiments for pre-release testing in confined use (laboratory, greenhouse or screen house), and for small-scale field trials. We also provide guidance on criteria important for designing ecologically relevant experiments.
a flow chart of the methodology for prioritizing non-target species and ecological processes
Pentatomid bug with boll weevil
spider on a cotton leaf
wasp parasitoid (Braconid)