Faunal Change of Bivalves in Ariake Bay after the Construction of a Dike for the Reclamation of Isahaya Bay, Western Kyushu, Japan

Drastic change of bivalves and gastropods caused by the huge reclamation projects in Japan and Korea

“…In June 1997, Modiolus (M.) comptus was generally distributed at the area of sediment with medium particle diameter (Md) of 1.5-2.0f (Fig. 9, Kanazawa et al 2005). From June 1999 to June 2000, the distribution area of sediment with Mdf 1.5-2.0 reduced in and around the mouth of Isahaya Bay, and Modiolus (M.) comptus temporarily disappeared from this area (Fig.…”

“…However, DO values were Ͼ4 mg L Ϫ1 in June 2000 and June 2002 (Fig. 7), and they were always Ͼ6 mg L Ϫ1 in November during 1998 and 2003 (Kanazawa et al 2005). (Fig.…”

“…However, a bivalve species, Modiolus (Modiolus) comptus Sowerby III (1915), distributed in the medium sand sediments, was abundant from June 1997 to June 1999 ( Fig. 9, Kanazawa et al 2005). Also, in June 1997, hypoxic water occurred near the region where the former 5 species lived rather than the region where M. (M.) comptus lived (Figs.…”

“…. Moreover, in the outer part of Isahaya Bay, environmental conditions suddenly changed, and fauna of bivalves was replaced on a drastic scale (Sato & Kanazawa 2004, Kanazawa et al 2005.…”