Recent reports on seaweed and seagrass establishment and restoration

Abstract

In recent years, natural seaweed and seagrass beds in Japan have been depleted; at the same time artificial seaweed and seagrass beds have been created in order to restore ecosystem functions of coastal waters. Vigorous efforts are being made to recover and re-establish endangered seaweed and seagrass beds in Japan. Fishermen have been transplanting kelp and seedlings using a spore-bag technique for many years. Regenerated seaweed beds are being developed on artificial structures at both the prefectural and national levels. The seaweed beds so created are sometimes protected from fish and sea urchin grazing. Furthermore, the concept has been extended to include the creation of “marine farms” using sea walls, coastal defenses and structures as breakwaters. The recent construction of artificial islands and underwater “mounds” have also increased seaweed bed productivity and associated fishery resources. Artificial seagrass beds have been created by transplantation to new sand-mud substrata and by seeding in the Seto Inland Sea. However, the creation of new seagrass beds is greatly affected by currents and sand-mud conditions at most of the experimental sites. © 2002, The Japanese Society of Fisheries Science. All rights reserved.