AA.B1E1 Baltic photic hard clay dominated by Mytilidae


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic photic bottoms at least 90 % coverage of hard clay. Epibenthic bivalves cover 10% of the seabed, of which Mytilidae constitutes at least 50 % of the biomass.

Physical environment       

Substrate is hard clay.

Characteristic species        

Mytilus spp., Modiolus modiolus

Correspondence with other classification systems               

HELCOM 1998:

2.3 Hard clay bottoms Hard clay bottoms with little or no macrophyte vegetation


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