Influence of aquaculture facilities on water flow at semi-closed water areas

In Hokkaido, more than 30 semi-closed water areas exist, and aquaculture has been performed in many of those water areas. Since semiclosed water areas connected to open sea by a narrow inlet are very calm water area, such areas are suitable for the aquaculture of scallops, oysters, and other marine products. However there is also the risk that the water quality may suddenly decrease with change of the surrounding environment. For permanent use for aquaculture, maintenance of the water quality is needed. As one of the water quality preservation methods, promotion of water exchange has been pointed out. Although the aquaculture facilities densely installed in water areas are one factor that worsens water exchange, flow analysis and evaluation of amount of water exchange in considering the influence of aquaculture facilities has not been performed. In this paper, the influence of aquaculture facilities on water exchange clarified by the flow analysis that set up fluid resistance is described.