Abstract
The generation and movement of dysoxic water mass in bottom water in the head of Ariake Sea and the Isahaya Bay were examined from results of sea water density and dissolved oxygen observed in 2007, 2013 and 2014. In addition, a numerical simulation was conducted to estimate the effect of the Isahaya Sea Dyke on the stratification in the head of Ariake Sea and the Isahaya Bay in case of summer in 2007 with and without the dyke. It was revealed that (1) the stratification occurred severally in the head of Ariake Sea and the Isahaya Bay in the summer of 2007, 2013 and 2014, (2) the dysoxic water mass could not move from the Isahya Bay to the head of Ariake Sea through the bottom water layer; and (3) the effect of the dyke on stratification was limited in a small area in front of the dyke.
