The effect of the Wave-dissipating block on the structural characteristics of the coral community

A case study of the east coast area of northern Okinawa

Abstract

Structures such as Wave-dissipating blocks, which were constructed in large scale projects about 30 years ago, are scheduled to be removed as the project ends. However, large corals inhabited the quiet waters formed by these structures, and it seemed to be functioning as a source of coral larvae to the surrounding sea area. And the biodiversity of the entire sea area might be increased by this specific environment. In this case, the natural environment of the area would be preserved better by leaving these structures. But, it is difficult to predict and evaluate this in the assessment at the beginning of the project. It is necessary to seek conservation measures based on the voluntary assessment with the evaluation by the expert opinion committee, and other laws and regulations (the Natural Parks Act, Fisheries Resources Protection Act etc).