As a result, the living organisms which inhabit them are different. Posidonia is found from shallow waters to a depth of 35 or so metres and their olive-like seeds are washed up on some beaches in Spring. Sea balls are Posidonia roots and stems worn into shape by rolling on the seabed-they are washed up in autumn and winter. Shingle beaches are often the poorest of the shoreline habitats as practically nothing survives the grinding action of such boeaches during periods of rough weather. Brown algae in a crevice on a rocky shore.
Rocky shores are also ol many different kinds.
The most notable and interesting are the hard limestone shores. What is most interesting in such areas. The shelf can be narrow or it may be several metres wide. In areas exposed to waves it can be in a series of steps, the higher ones in the most exposed areas, the lower ones in the more sheltered parts of the coast. Or it can be on one level if there are no significant differences in wave exposure.