Abstract
Many species of Japanese marine molluscs are threatened and facing extinction. The following characteristics are found in this case, 1) many species are threatened, 2) the most common and representative species of the ecosystem in the past are also threatened, 3) species that inhabit estuary and inner bay areas are especially threatened, and 4) species that inhabit sandy and muddy bottoms are also threatened. A total of 433 species of threatened molluscs are listed in the Red Data Books and conservation reports. This fact suggests that the Japanese marine ecosystem is now in danger. Molluscs have a lot of species diversity with ecological characteristics in various habitats, and thus, molluscs are one of the most suitable groups for assessing of the marine ecosystem. I have carried out a conservation movement of molluscs in the tidal flats and salt marshes as an amateur researcher in Kyushu. In this paper, I emphasized the importance of tidal flat and salt marsh bearing a primitive ecosystem. Transplanting molluscs has many problems as a method of mitigation. I suggested that coastal faunal conservation should be achieved by the preservation of habitats. On a project of local development in modern times, it is essential to consider the biodiversity at an early stage of the project. Inventories of important local ecosystems in the aspect of malacology and establishment of sanctuaries are also neccessary. In this respect the demand for participation of amateur researchers on conservation movements of biodiversity has increased recently and their activities would have essential roles in local environmental conservation.
