AB.E1E1 Baltic aphotic shell gravel dominated by Mytilidae


HELCOM RED LIST Biotope Expert Team

Textual description 

Baltic aphotic bottoms at least 90 % coverage of hard clay. Epibenthic bivalves cover at least 10%of the seabed and more than other perennial attached erect groups. Out of the epibenthic bivalves, Mytilidae constitutes at least 50 % of the biomass.

Physical environment       

Substrate is shell gravel.

Characteristic species        

Mytilus spp., Modiolus modiolus

Correspondence with other classification systems               

HELCOM 1998:

2.6 Shell gravel bottoms

2.6.1 Aphotiz zone

HELCOM 2007:

Shell gravel bottoms

- Habitat under threat and/or in decline in all areas of occurrence

The Southern Baltic Proper, The Gulf of Gdansk, Bay of Mecklenburg, Kiel Bay, Little Belt, Great Belt, The Sound, Kattegat

EUNIS 2012:

A5 Sublittoral sediment

A5.1 Sublittoral coarse sediment

A5.11 Infralittoral coarse sediment in low or reduced salinity

A5.115 Baltic shell gravel bottoms of the aphotic zone

OSPAR list of threathened biotopes:

Modiolus modiolus beds

- Habitat occurs in the OSPAR Region II (including Kattegat) and is listed threatened and/or declining in this region