Aquaculture is a rapidly growing food producing sector. The sector has grown at an average rate of 8.9% per year since 1970, compared to only 1.2% for capture fisheries and 2.8% for terrestrial farmed meat-production systems over the same period (FAO, 2004). In contrast to aquaculture, capture fisheries landings as a whole is stagnant. Although catch rates for some species did not decline during the 1990s, most ocean fisheries stocks are now recognized as fully or over fished. The worldwide decline of ocean fisheries stocks and the further expansion of the human population are an incentive for the further growth of aquaculture. Despite the growth of the sector, aquaculture production still needs to increase 5-fold in the next 2 decades in order to satisfy the minimum protein requirement for human nutrition (FAO, 2004).