| The Seto Inland Sea is the largest enclosed sea in Japan (22,000 km(2) surface area), and is very shallow (average depth of 37 m). Large Zostera marina L. beds throughout the Sea play an important role in its ecosystems and environments. This study reviews the long-term changes in the area of the Zostera beds, as well as some direct and indirect environmental factors which influence their distribution. In 1924, the area of the beds was 4,137 ha in the waters of the Okayama Prefecture, By 1989, 87 % of these beds had been lost. Industrialization and urbanization around the coasts of the Seto Inland Sea began in the 1950s. In the 1960s, the area of the Zostera beds in this Sea amounted to 22,625 ha. Since 1977, 70 % of these beds has been lost. This decline... |
