抄録
The objective of this study was to evaluate the restoration of eelgrass (Zostera marina L.) beds by filling up borrow pits along the coast of Iwakuni, in the Seto Inland Sea, Japan. We constructed an eelgrass habitat at the edge of previously constructed borrow pits in eelgrass beds by filling up the pits with natural sediment. We monitored sand movement, underwater irradiance and eelgrass shoot density in the constructed and natural habitats. Sand movement in the constructed habitat was from -8 cm to 9 cm, which is slightly different from that in the natural habitat. The averaged underwater irradiance in the constructed habitat was more than 3 mol photons · m-2 · day-1, which was the amount necessary for eelgrass. Eelgrass disappeared after typhoon occurrences in 2004-2006, whereas seedlings of eelgrass have continuously appeared in the constructed and natural habitats every winter. These results suggest that the restoration of eelgrass habitats by filling up borrow pits is a useful technique for eelgrass bed restoration.
