Underwater Observations on the Fauna of Shallow Rocky Areas in the Neighbourhood of Plymouth

A brief description is given of the commonest sessile animals observed by diving from twelve positions near Plymouth, including three offshore reefs. The coelenterate Corynactis viridis is generally abundant on shaded rock surfaces. Many sessile species, even where common, tend to be dispersed in scattered patches or colonies; from this it is suggested that their distribution is affected by predation from browsing animals, particularly Echinus esculentus.