ENVIRONMENTAL SURVEY OF ARTIFICIAL REEF AND DISCUSSION ON CORAL DISTRIBUTION CHARACTERISTICS IN HAMASAKI COAST

Abstract

 In the coastal area, new breakwaters and seawalls have been constructed and existing structures have been strengthened to ensure safety and security against storm surges, high waves, and tsunamis. Although "disaster prevention" and "environment preservation" have often been regarded as conflict relation, it is desirable for coastal protection projects to be coexistent in the future projects. This study focused on the artificial reef at Hamasaki coast in Motobu town, Okinawa Prefecture, and conducted water quality and coral distribution survey with the purpose of clarifying the factors why coral growth status are better than neighboring structures. As a result of water quality survey, there are little differences in water temperature and salinity between the survey lines and the tide conditions, but DO tended to be higher in the surface layer near the artificial reef. Moreover, the results of analyzing the cover rate according to the type of coral indicated that there is a difference depending on the section, and the cover rate of coral on the southern offshore side is higher than the other sections.