Abstract
Many studies about long term change of the aquatic environment in Ariake Bay using the monthly-observed water temperature and salinity data are performed, but the conclusion occasionally varies from study to study. In this study, we performed the re-analysis which adds the new data to the previous study based on the monthly-observed water temperature and salinity data, and considered the relation between the variation in stratification and the closed sea dyke of Isahaya Bay, year-to-year variation river discharge, and variation in tide. As a main result, it became clear that the significant variational tendency isn't found because the surface salinity of Ariake Bay inner part has been strengthened after the closed Isahaya sea dyke, and the stratification potential is had a great influence by the year-to-year variation river discharge.
