Marine, intertidal, gravel, protected, eulittoral

Few areas are mapped as this category because wave-protected areas tend to be characterized by mud rather than gravel. Gravel beaches seldom have one uniform grain size; most surveys report some sand mixed in.  These protected beaches are less disturbed by waves, contain more sand, are more stable, and consequently have higher biological diversity. They tend to have no plant life, however, and are occupied by mobile burrowing animals or epibenthic forms such as shrimp.