1.Background and PurposernIntroductionrnAquaculture production and trade in aquaculture products continues to grow at a fast pace,responding to increased global demand for fish,shrimp,mollusks and other aquatic products.In 2004,aquaculture production reached59 million tones,with a farm gate value of $ 70 billion.Developing countries dominate aquaculture production and trade,contributing over 80％ of production and 50％ to the value of internationally traded aquatic products.Aquaculture is making an increasingly significant contribution to the global seafood trade,as well as to domestic consumption,and will continue to grow due to stagnating wild capture fisheries supplies.