One of the purpose of environmental restoration in coastal area is to revive an ecosystem in which the material cycle from suspended solid proceeds successfully. In this paper, we investigated bioturbation of sediment by the dominant deposit-feeding species of sea cucumber Stichopus japonicus in coastal sandy mud bottom.
Conclusions are as follows: 1) There were no feeding activity with a rise of water temperature, and concentrations of organic matter did not differ in respect with the presence of sea cucumbers. 2) Moving behavior of S. japonicus had decreased concentrations of reduced sulfide within the depth of 2cm. 3) The effects of bioturbation by S. japonicus acted to increase the number of infaunal bivalves, which may increase the amount of food for S. japonicus.