Rice and fish are important in Asian diets. Up to now the supplies of rice and fish have come from differentRice and fish are important in Asian diets. Up to now the supplies of rice and fish have come from different sources. The traditional practice of catch-ing wild fish in ricefields is insignificant today. Recent investigations however,have indicated that integrated rice-fish systems offer possibilities of increasing rice yields by as much as 15% and at the same time harvesting up to 500 kg/ha of fish every rice crop. ICLARM' s ecological modelling software ECOPATH H applied by a team of ICLARM, IRRI and CLSU scientists raises the question whether managing ricefields as a sustainable production system may require integration with fish.