Modeling of dissolved oxygen of aquaculture grounds in a semi-enclosed bay

Coastal aquaculture has been increased and developed in a semi-enclosed bay. In Sido Bay, lasted northeast side of Kagawa Pref., could produce marine aquaculture productions to supply the population demands. The feeding rate of fish farming is approximately 12,378 tones a year, with the highest rate in summer. Therefore, the pollution from floating aquaculture cage can affect the environment via fecal waste, dissolved waste and excess feed settles. After the field experiments, it was found the tidal current, bottom topography and DO consumption rate by sediment are important factors to evaluate the carrying capacity of aquaculture grounds. The authors proposed a more appropriate evaluation method for DO by using 3-dimensional numerical model taking the effect of oxygen consumption by the fish in the aquaculture cage and bottom sediment into consideration.