Algae

Seaweeds are one of the most conspicuous features of rocky shores and in areas where there is little wave action they may be present in such high densities that they dominate the shore. In common with higher plants, they are capable of photosynthesis and are thus restricted to the shore and shallow and surface waters where there is adequate light. Seaweeds are macroscopic marine algae. Most are firmly anchored to the substratum by a holdfast, although unattached forms are frequently found in calm waters.