In developing more effective and sustainable exploitation of fish populations, the systematic use of the considerable battery of genetical techniques now available (see e.g. Beardmore, 1998) is still relatively underdeveloped. This statement holds whether we consider natural populations, enhanced populations or cultured stocks. However, there is increasing recognition that combining well established techniques such as the selective breeding programme carried out on Atlantic salmon (Gjoen and Bentsen, 1997) with appropriate molecular techniques, should yield valuable results in aquaculture.
Of the range of molecular techniques available, some may be considered as platform technologies following the terminology of Hew and Fletcher (2001), and of these it seems likely that transgenesis will be one of the most significant.
The production of appropriate genetically modified organisms or GMOs (in some cases combined with other forms of genetic improvement) offers considerable opportunities for more efficient and more effective aquaculture across a wide range of species (see for example Sin, 1997). This is likely to be achieved by intervention aimed at removing or reducing current constraints to better production, some of which are listed in Section 3.
The value of GMOs in agronomy is already widely accepted, as the area sown to transgenic crop species world wide exceeds 60 million hectares and this area is increasing rapidly year by year. However, both in terrestrial and aquatic animal species, while many GMOs have been produced, we have not succeeded in obtaining any hard evidence of commercial use. In aquaculture Dunham (1999) has a statement that this is taking place in New Zealand and Scotland though we have no further evidence that this is indeed the case. Carr (1999) refers to small scale production in Cuba though several Cuban scientists have assured one of us (JAB) that there is no commercial production in that country. However, given the drive towards large increases in aquaculture production evident in some countries, e.g. China (Qi Jingfa, 2002) it seems inevitable that commercial production of aquatic GMOs will not be long in coming.
In this paper, our purpose is to discuss, for the benefit of the general community of aquaculturists as well as aquacultural geneticists, the nature of GMOs, the range of aquatic species in which GMOs have been produced, the methods and target genes employed, the benefits to aquaculture, the problems attached to use of GMOs and the regulatory and other social frameworks surrounding them. We conclude with a set of recommendations aimed at best practice.