Marine, intertidal, mixed coarse, partially exposed, eulittoral

Mixed-coarse sediments are those where no one grain size occupies more than 70 percent of a stretch of beach. Instead, the beach is a mix (in variable quantities) of a few boulders, with cobble, gravel, and sand. Such sites often exist where sea stacks or other features reduce the wave energy reaching the shore. These habitats usually have very high species diversity because of the range of microhabitats they provide: stable tops of cobbles, undersides of cobbles, among loose sediment, and within the stable sediment beneath the cobbles. Clams often thrive in this sediment because it is hard for predators to dig to them. Drift algae may accumulate in these habitats, providing additional food and habitat for a variety of organisms.