Research report Ecological and experimental constraints for field trials to study potential effects of transgenic Bt-crops on non-target insects and spiders
Field trials are an important element of the environmental risk assessment that is a part of the authorisation procedure for cultivation of a GM crop. Field trials are used to detect potential adverse effects on so-called non-target organisms. Field trials are considered increasingly important in environmental risk assessment and the requirements that are set for field trials are expanded. In the EFSA guidance on the environmental risk assessment of GM plants great importance, for instance to detect unexpected effects, is attached to field trials.
In field trials, significant effects on non-target organisms are, however, rarely observed. External factors may influence the results of field trials and may mask potential differences. In addition, conducting a field trial is complex and expensive.
COGEM has commissioned a research project to analyse to what extent field trials with GM crops are able to detect potential effects on non-target organisms, to investigate the limits of field trials, and to list the requirements that should be met when conducting a field trial.
The results from this research project indicate that field trials are only able to detect large effects on non-target organisms. Field trials are not capable to detect small adverse effects. It is also not possible to detect potential effects on non-target organisms if the non-target organisms of concern are mobile, present in low numbers, or when the natural variability in abundance is large.
COGEM considers the results from this research project important for the discussion and decision on declaring the EFSA guidance for the environmental risk assessment on GM plants legally binding. In view of the results of this research project, adjustment of the guidance document before giving them the force of law seems necessary.