NUMERICAL-SIMULATION MODEL FOR QUANTITATIVE MANAGEMENT OF AQUACULTURE

A numerical model is developed for aquaculture management, which consists of four parts: (1) a current simulation model, which calculates tidal and wind-induced currents, (2) a chemical oxygen demand (COD) diffusion model, which calculates spatial distribution of COD using the simulated current, (3) a dissolved oxygen (DO) diffusion model, which calculates the spatial distribution of DO, and (4) an accumulation model, which calculates the distribution of deposits from fish aquaculture. Our model is capable of calculating the detailed spatial distribution of COD and DO by dividing the bay into many grid points. It also takes into consideration the effects of feed and fish in each rafts and the loading of COD from rivers. Using this model, we can assess the influence of the location or the area of aquaculture rafts on the ecological and/or environmental system. It is also of practical use in order to obtain a better distribution of rafts in bay areas, or to calculate the basic data for the renewal of licenses of an aquaculture business. The model is applied to Mikame Bay in Ehime Pref., west Japan, as a case study.