Abstract
The Okhotsk Sea of Hokkaido is covered with drift ice in winter. Drift ice which rushed into Saroma Lagoon caused heavy damages to scallops and oysters, and its facilities. So the ice boom which prevents the drift ice from rushing into is started constructing in 1994, and is completed its 80%. Especially, ice boom with net that set at the center of lagoon mouth completely shut out the drift ice. However, decrease of the amount of sea water exchange is worried about.
In this paper, the authors make two experiment about movement of ice floe, and prove that quality of water does not become worse because of ice boom construction.