Effects of change of density stratification due to Isahaya Sea-Dyke on the fate of anoxic water in the Ariake Sea

Abstract

Abstract In this study, we aim to investigate the possibility that the construction of the Isahaya Sea-Dyke significantly causes anoxic water development in the bottom layer in the Ariake Sea, Japan. We numerically compared the vertical distribution of dissolved oxygen (DO) in the water column between two cases with the dyke and without it. As a result of this research, the followings are clarified: 1) DO totally decreased in Isahaya Bay due to construction of Isahaya Sea-Dyke; 2) The effect is relatively small during neap tide, but is larger in spring tide; and 3) The effect is not shown in the main body of the Ariake Sea.