In the rocky and gravely bottoms there are endolithic and epilithic species, and some soft bottom species. It was possible to distinguish in these bottoms the following communities: 1) supralittoral rock; 2) upper mediolittoral rock; 3) lower mediolittoral rock; 4) infralittoral rock; 5) infralittoral gravel; 6) circalittoral rock; and 7) semi-obscure caves.
