Shrimp farms are scattered throughout the country but 55% can be found in Southern Thailand, 35% in the eastern part and some 10% in the central. About 80% of the shrimp farms are smaller than 1.5 ha 18% are between 1.5 and 2.5 ha and only about 2% are larger than 10 ha. (Rosenberry,1997). However, large-scale farms supply about 30°/o of the countryis total shrimp export.