AB.B1E Baltic aphotic hard clay characterized by epibenthic bivalves


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic aphotic zone bottoms with at least 90 % coverage of hard clay. Sessile/semi-sessile epibenthic bivalves have a coverage of at least 10%.

Physical environment       

Substrate is hard clay. Typically high energy exposure areas.

Characteristic species        

Mytilus spp.

Quality descriptors             

Diversity, abundance and biomass of fauna.

Geographic range               

Whole Baltic Sea

Anthropogenic threats     


Correspondence with other classification systems               

HELCOM 1998:

2.3 Hard clay bottoms

2.3.1 Aphotic zone