part of has part composed primarily of continental shelf marine neritic benthic zone biome marine reef mussel reef envoCmecs The CMECs classification references shelf reefs in the definition. Thus this term is focused only on mussel reefs that are neritic. CMECS:338 A marine reef which is primarily composed of self-adhered or conglomerated mussel shells. envoMarine mussel reef substrate This class aligns to the Coastal and Marine Ecological Classification Standard (CMECS). In ENVO, we may adapt the definition for consistency, but the semantics (meaning) of the term should be unaffected. Please consult the CMECS catalogue (https://cmecscatalog.org/) for authoritative and semantically unconstrained definitions. https://cmecscatalog.org/cmecs/classification/unit/338.html Modiolus Mytilus ecological community