부산대학교 도서관

Since April 1997, the inner part of Isahaya Bay has been isolated from Ariake Sea by a dike for reclamation. We periodically monitored water quality, grain-size of bottom sediments and benthic animals by the samples collected at (1) 50 fixed stations around inner part of Ariake Sea and (2) 16 fixed stations inside of the dike in June 2021 and June 2022. Both in the inner and outer parts of Isahaya Bay, the number of species and mean individual density of benthic animals have been still smaller than the past. After the shut-off, benthic animals rapidly decreased from 1998 to 2001, and then only few species increased from 2002 to 2003. However, from 2004 to 2022, most of them have disappeared or decreased rapidly around the central part of Ariake Sea. Based on the data obtained in these 25 years, the future trends in changes of benthic animals were predicted in both cases of opening and non-opening gates of the dike. The results of our research were published in scientific journals as well as explained to the public at local meetings. It is greatly expected that the results of our research will be helpful for future investigations on effects of the dike to the status of Isahaya Bay as basic scientific information.