Just to add my comments to the discussion on control of genetically modified organisms (GMOs) that might be introduced in developing country aquaculture. I make these comments, having been involved in research on the development, application and dissemination of genetic technologies (although not those that might be considered "biotechnology") in developing country aquaculture (mainly Asia) for over 10 years.
I think the first comment should be that physical containment of a species that have the capacity to survive in the developing country environment (which includes almost all commercially cultured species) would be virtually impossible. Tropical countries are exposed to greater environmental extremes, particularly flooding, and based on my experience of many years working in genetics research in Asia, I would never like to guarantee that any domesticated fish cannot escape from an aquaculture facility. Of course on top of this you have the human element and you can be fairly sure that if a fish is considered superior for aquaculture, its movement will be impossible to control completely.
Given the impracticality of physical containment, triploidy was proposed as a method of sterility. Several reservations have already been expressed related to:
- The difficulty in producing reliably 100% triploid
- The possibility that triploids might not be 100% sterile or could revert to a diploid state
- The prospect that triploids, even when sterile, can still interfere with reproduction and breeding of wild populations
I would like to add to this, that the application of triploidy in commercial stocks (mainly salmonids and grass carp) has been limited to species that are habitually bred using artificial fertilization and incubation. For most of the important species in developing country aquaculture (namely tilapias and carps) artificial fertilization is rarely used and therefore application of triploidy on a commercial scale would be very unlikely to be viable.
I am aware of at least one research group that is working on the induction of sterility through transgenesis itself (introduction of an antisense gene). The objective of this research would be to produce a selectively sterile fish which would only reproduce upon application of exogenous hormones/steroids to replace those missing from the disruption of its own biochemical/physiological pathways. It will of course be necessary to have some (selectively) fertile offspring to produce the future generations of transgenic fish. This may offer the best option for control of transgenics in the long run.
More generally, my feeling is that the emphasis on issues related to the uptake of GMOs differ quite greatly between developed and developing countries with the result that cost:benefit ratios look very different. Whereas in developed countries, consumer concerns presently dominate the discussion and limit uptake, these are far less prominent in developing countries, particularly where food security itself is a major issue. It was illuminating to see a recent documentary on the introduction of transgenic crops in India where the important issue was not one of environmental safety but of who controls access to and pricing of seed for production of transgenic crops.
I am not suggested that human health, and in particular environmental concerns should be given lesser consideration in developing countries, but I do think that it is inevitable that such issues will carry less weight in consideration of the efforts to ensure food security, where GMOs could clearly have a role to play. These result could well be that we see adoption of GMOs in aquaculture, first in developing countries. [In this context, see the message of Ashie Norris, 23 August.......Moderator]
Dr. Graham C. Mair
DFID Fish Genetics Program at AIT
Aquaculture & Aquatic Resources Management (AARM)
Asian Institute of Technology
PO Box 4, Klong Luang, Pathumthani 12120, Thailand
Tel/Fax 66 2 5245463; E-mail: [email protected]; Mirablis ICQ no. 7968035
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