In Malaysia, a study (RICE-FISH INTEGRATION IN MALAYSIA: PRESENT STATUS AND FUTURE PROSPECTS) was conducted concerning just such a system involving rice fields filled with fish that take advantage of the flooding during growing season, providing fertilizer for the rice crop before being harvested for eating or market at the end of the season. This shows just how large such a system can get with even the most basic provisions taken.
The abstract: "The biological and ecology of rice-fish farming system in Malaysia is reviewed and discussed. Ricefish integration is suitable for development in areas outside of the present rice growing scheme where optimization of land use would result in better income and reduce risks to small scale farmers. Although the biological and ecological findings indicate that the present rice-fish farming method is suitable, improvement to the system could be done in order to maintain or even increase fish production. Better management and improvement to rice-fish culture method should reduce the constraints to higher fish production. However, introduction or improvement of the present rice-fish farming system should take into account the site and socio-cultural specificity of the system. In areas where rice is the major crop, rice-fish farming would not be successful due to pressure on farmers to produce more rice to take advantage of the present rice subsidy program."
Read the entire study here, and for supplemental diagrams and pictures, see here.