Abstract
Faunal changes of benthic animals after the construction of dikes for reclamation were compared among case studies in Japan （Isahaya Bay）and Korea（Saemangeum and Shihwa）. After the isolation of Isahaya Bay in April １９９７, Musculista senhousia temporarily increased in May １９９７, and then Potamocorbula sp. and Corophium sinense replaced the pre-isolation benthic community in August １９９７. Potamocorbula sp. and Corophium spp. also increased in Saemangeum and Shihwa, western Korea after the dike construction. Therefore, it can be estimated that these species will also multiply after opening the gate of Isahaya reclamation dike, and the other marine species of benthic animals will increase according to the improvement of sediments by these pioneer species.
