Description of key species and physical characteristics

Although the five species under consideration here share some common features at the level of definition of biogenic reefs presented above, they are each quite distinct in physical form and are therefore described separately below. (This variation is further illustrated in the respective distributions as well as the underpinning environmental and ecological attributes discussed in subsequent chapters).

Sabellaria alveolata

Sabellaria spinulosa

Modiolus modiolus

Mytilus edulis

Serpula vermicularis