13. Recommendations for the decision-making processes relating to the market release of GM crops under progress can be derived from SIGMEA outcomes

Although gene flow is a common phenomenon for crop species, its implications for Genetically Modified Plants have raised new concerns. Undesirable effects related to gene flow may result in ecological or agronomic considerations (persistence of resistant volunteers, creation of new weeds, multiple resistances) as well as commercial considerations (unintended presence of GMOs in conventional crop production affecting its competitiveness in the marketplace). The coexistence between different types of crops is an important issue and has to be addressed once GM crops are approved in the EU. The European Union has issued guidelines designed to allow for the coexistence of various kinds of agriculture in support of its policy that “farmers should be able to cultivate freely the agricultural crops they choose, be it GM, conventional or organic” (Recommendation 2003/556/EC). New GMO regulations have been introduced as a basis for Member states to develop appropriate coexistence and traceability measures for delivery of food and feedstuffs complying with the labelling thresholds.

SIGMEA has produced a practical toolbox for addressing GM impacts in agriculture:

• A unique database including more than 100 data sets on geneflow and ecological impacts which may inform decision-makers on factors driving gene flow at the landscape level and on the variability of such processes across Europe, help regulators to set up coexistence measures at National levels as well as help scientists to identify further research priorities in that area.

• LandSFACTS is a user-friendly windows-based software to simulate crop allocation to fields by integrating typical crop rotations and crop spatio-temporal arrangements within agricultural landscapes and could be used for a practical implementation of coexistence measures

• The generic gene flow platform LandFlow-Gene, including validated rapeseed and maize modules and interfaced with the landscape generator LandSFACTS and GIS softwares, is now available as a prototype. It has been used to support regional case studies analysis and to set up scenarios for coexistence. This platform could be extended to other crops to provide a general framework for informing coexistence in all cropping systems of Europe.

• A user-friendly decision-support system (SMAC-Advisor) to assess maize coexistence feasibility at the field level was designed.

• Structural and organisational factors affecting coexistence in practice have been identified and strategies for managing coexistence at the regional level have been proposed;

• A comprehensive overview of monitoring and legal issues has been provided but, due to the delay in implementing regulations in most member states and the low development of commercial GM cropping in Europe, only general recommendations have been made.  
  

Altogether, these tools and outcomes can be combined to assess coexistence at various spatial scales (field, farm or region) and various decision-making levels (farmers, elevators, member states, EU). Depending on the decision problem and the amount of information available, various SIGMEA tools can be used.

SIGMEA findings make it possible to address issues such as "what will happen, in terms of gene flow, if a particular GM organism is introduced into a particular European region?" and "how can crops be deployed at the landscape level so as to maintain the adventitious presence of GMOs in conventional crops within the legal thresholds, or any specific market-driven requirements?".

The outcome of both field and modelling studies carried out in SIGMEA is that best practices for coexistence are highly variable and depend on local characteristics, crop practices, environments as well as farmer strategies and preferences, and that the feasibility of coexistence directly depends on the targeted threshold.

Based on regional case studies findings, contrasting global coexistence scenarios may be defined by considering different regulation approaches:

SIGMEA has developed tools to support the definition and implementation of flexible measures. Predictive gene flow models are now available (currently only for maize and oilseed rape but easily extendable to other crops). These can help decision-makers assess the feasibility of coexistence at the field, farm and silo level for the various targeted thresholds under various environmental and agronomic conditions. In addition simple decision-support tools, like SMAC Advisor can be used by farmers or advisors who would like to quickly assess coexistence feasibility using limited amounts of information at a local field level. 

It has been stressed that a coexistence regime based on “uniform isolation distances”, as implemented so far in several member states, is not optimal, not proportional and may lead to unnecessary additional costs or render coexistence impossible in practice.