Improvements in production methods over the last two decades have resulted in aquaculture becoming a significant contributor to food production in many countries.  Increased efficiency and production levels are off-setting unsustainable capture fishing practices and contributing to food security, particularly in a number of developing countries.  The challenge for the rapidly growing aquaculture industry is to develop and apply technologies that ensure sustainable production methods that will reduce environmental damage, increase productivity across the sector, and respect the diverse social and cultural dimensions of fish farming that are observed globally.  The aquaculture industry currently faces a number of technology trajectories, which include the option to commercially produce genetically modified (GM) fish.  The use of genetic modification in aquaculture has the potential to contribute to increased food security and is claimed to be the next logical step for the industry.  However, the potential use of these technologies raises a number of important ethical questions.  Using an ethical framework, the Ethical Matrix, this paper explores a number of the ethical issues potentially raised by the use of GM technologies in aquaculture.  Several key issues have been identified.  These include aspects of distributive justice for producers; use of a precautionary approach in the management of environmental risk and food safety; and impacts on the welfare and intrinsic value of the fish.  There is a need to conduct a comparative analysis of the full economic cycle of the use of GM fish in aquaculture production for developing countries.  There is also a need to initiate an informed dialogue between stakeholders and strenuous efforts should be made to ensure the participation of producers and their representatives from developing nations.  An additional concern is that any national licensing of the first generation of GM fish, i.e., in the USA, may initiate and frame an assessment cycle, mediated by the WTO, which could dominate the conditions under which the technology will be applied and regulated globally.  Therefore, an integrated analysis of the technology development trajectories, in terms of international policy, IPR, and operational implications, as well as an analysis of a broader range of ethical concerns, is needed.