2006 年 22 巻 p. 981-986
In Hokkaido, more than 30 semi-closed water areas exist, and aquaculture has been performed in many of those water areas. Since semi-closed water areas connected to open sea by a narrow inlet are very calm water area, such areas are suitable for the aquaculture. However there is also the risk that the water quality may suddenly decrease. For permanent use for aquaculture, maintenance of the water quality is needed. As one of the water quality preservation methods, improvement of water quality by promotion of water exchange has been pointed out. Many of these water areas are located on the coast of the Okhotsk Sea. Ice floes normally reach the coast in winter, tides cause ice floes to pass through lagoon inlets into the lagoon. These ice floes have caused serious damage to aquaculture facilities. To prevent such damage, ice booms had started to be installed. However, these facilities have been used only during winter. In this paper, it proposes that the method of water quality improvement by use of these facilities.