Abstract
Long‐term biofouling communities on stationary man‐made substrata in the shallow waters of northern seas as a rule are composed of mussels. Prolonged investigation of the structure and dynamics of epibenthic communities in the White Sea and the Shallow waters off East Kamchatka (1976–1990) showed that the mussel community is not completely stable. Succession of this community is cyclical in character when the habitat is unstable. Such unstable habitats are most common in estuarine zones where large hydrotechnical structures are usually concentrated. Many of these structures have steel surfaces which constantly suffer the corrosive effects of the marine environment. In stable habitats with inert substrata and insignificant salinity gradients, a mussel community is not a terminal stage of succession. Duration of the mussel successional stage is about 10–20 years, and this is followed by the climax communities which are typical of a given climatic zone. Thus, it can be concluded that the mussel community is not a climax community but a relatively stable point in a prolonged multi‐staged succession.