This document presents an abbreviated summary of discussions in the FAO e-mail conference entitled "Gene flow from GM to non-GM populations in the crop, forestry, animal and fishery sectors", which took place from 31 May to 6 July 2002.
It was the seventh conference hosted by the FAO Electronic Forum on Biotechnology in Food and Agriculture since its launch in March 2000. The theme of the conference was clearly of major interest - although running for a shorter time period (5 weeks) than previous Forum conferences, more people joined (382) and sent messages (61) than in any of the previous six conferences. A broad range of stakeholders participated, with 32, 24, 17 and 13% of messages coming from people working in universities, research centres, non-governmental organisations and private companies respectively. Roughly one third of the 118 messages posted were from participants in developing countries and two thirds from developed countries.
During the moderated conference, discussions focused overwhelmingly on the issues concerning gene flow in the crop sector with only a few messages dedicated solely to these issues in forest trees, fish or animals. From the discussions it was clear that widely differing opinions are held regarding genetically modified organisms (GMOs) and the current or potential impacts of gene flow. (Note, unless otherwise stated, the term gene flow used in this document refers to gene flow from GM to non-GM populations).
The main topic of discussion in the conference was the real or potential ecological impacts of gene flow and, in addition, how a science-based ecological risk assessment framework might be applied to gene flow.
Regarding the ecological impacts, discussions focused on two main areas. The first was the impacts of gene flow on biodiversity. Here, it was argued that transgene flow might have greatest impact on the within-species genetic diversity of domesticated populations and, secondly, that other factors (such as the introduction of invasive alien species) could have far greater impacts on biodiversity. These other negative factors were either seen as putting gene flow in perspective as a minor problem or, alternatively, they encouraged participants to call for prudence as, initially, people had often not considered their potential risks. The second area was the ecological impacts of specific transgenes - either those currently in use, affecting herbicide tolerance and insect resistance traits, where it was argued that spread of these transgenes to non-target plants could have or already had negative ecological impacts (the case of herbicide tolerant GM canola in Canada was mentioned in particular), or transgenes that might be used in the future. Because different transgenes may raise different ecological issues in different environments, it was proposed that the ecological impacts of gene flow should be considered on a case by case basis rather than as a whole.
Assessing the ecological risk of gene flow was considered by participants to be very important prior to GMO release. In this context, there was much detailed discussion about two key terms that need to be considered in an ecological risk assessment framework i.e. hazard (undesired/injurious events or harm caused by gene flow to the environment) and exposure (the frequency of gene flow or the probability of the transgene spreading in the environment). The problems of identifying the hazards and testing for them were raised, as well as the complexities involved in predicting exposure. Participants were generally positive about using population genetics mathematical models for predicting the spread of transgenes in the wild.
A number of messages dealt with specific aspects of ecological risk assessment in developing countries. Here, the lack of key information on the ecology of native plant species was a common theme and the need to generate this information to enable risk assessment to be carried out using local ecological information was emphasised. It was also argued that the assessment needs to be based on the realities of local farming systems in developing countries, where farm sizes may be small and mixing of varieties and seed saving may be common practices.
Several participants emphasised the importance, after carrying out an ecological risk assessment of gene flow from a GM variety, of weighing up the risks in a bigger context i.e. against the gene flow risks associated with conventional breeding practices; considering the environment in which the GM varieties might be used (e.g. whether suffering environmental degradation) and, thirdly, against the potential benefits of the GM variety.
Three other topics that generated a good deal of discussion were i) whether GMOs are fundamentally different from conventionally bred organisms (CBOs), thus entailing new gene flow hazards ii) strategies to limit gene flow and iii) economic impacts of gene flow.
There was no consensus on the first of these topics, which was highly contentious, resulting from a dichotomy in the way that GMOs are viewed in relation to CBOs. For participants who considered that GMOs do not differ fundamentally in their genetic make-up from CBOs, gene flow from GM-populations was not more of an issue than gene flow from non-GM populations. For those, on the other hand, who considered them to be fundamentally different, it was important that the unique features of GMOs be identified and the consequences of their dispersal by gene flow be evaluated. The two main unique features proposed in this context were that GMOs may transfer exotic/foreign genes (of other species) to individuals of the same population, to wild relatives or to different species, with potential evolutionary implications, and, secondly, that the genetic modification process may create organisms that are potentially unstable, due to the way transgenes are regulated and since transgene insertion could damage the host DNA.
For the second topic, given the concerns about the ecological impacts of gene flow, as well as the potential difficulties involved in assessing its ecological risk (due to problems in identifying potential hazards and predicting exposure), an alternative approach proposed was to simply prevent or limit gene flow from GM populations. This seemed to receive general support from all parts. The pros and cons of a range of different strategies were discussed, including temporal or spatial separation of GM and non-GM populations; ensuring that GMOs (or the pollen) are sterile or chloroplast genetic engineering (where the transgene(s) is inserted into the chloroplast genome rather than the nuclear genome). It was also suggested that these strategies might be combined.
The third of these topics dealt with two main aspects concerning the economic impacts of gene flow: the potential negative implications for trade and export to non-GMO markets if gene flow occurs (mentioned as being especially detrimental for developing countries) and, secondly, the impacts of intellectual property issues, as ownership of genes or seeds raises the question of liability if gene flow causes damage and, secondly, patent owners may decide to enforce intellectual property legislation if gene flow takes place.
Finally, three other topics were given minor attention in discussions. The first was a reminder that, apart from the ecological and economic impacts, there is also a philosophical/ethical dimension to the gene flow question. The potential importance of this aspect for indigenous peoples was mentioned. The second was gene flow in centres of origin and diversification, where participants emphasised that the topic requires special attention because of the complex mixture of scientific, social and cultural issues that it raises. The third was gene flow to organic agriculture, which is an especially sensitive issue as organic agriculture does not permit use of GMOs. The specific case of organic canola farming in Canada was discussed.
A more detailed summary, including references to specific e-mail messages, has been published and is available at http://www.fao.org/biotech/logs/C7/summary.htm. The individual e-mail messages can be read at http://www.fao.org/biotech/logs/c7logs.htm.
[Abbreviations: CBOs = Conventionally bred organisms; FAO = Food and Agriculture Organization of the United Nations; GMOs = Genetically modified organisms].