Abstract
The purpose of this study is to disclose the relationship between marine organisms and sediments in gravel beach. From this viewpoint, the field observations on marine organisms are carried out in a man-made gravel beach and natural one. It is found that the diversity index of marine organisms in gravel beach depends on the time of exposure from sea water and the volume of gravel. For this reason, the the diversity index on marine organism in natural gravel beach is larger than those in man-made one and natural rocky coast.
