AA.M1R Baltic photic mixed substrate characterized by soft crustose algae


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with more than 10 %, but less than 90 % coverage of both hard and soft substrata. Coverage of soft crustose algae is at least 10 %, while perennial attached erect groups and unattached algae cover less than 10%.

Physical environment       

Salinity range: moderate to high; Exposure range: moderate to high; Depth range: photic zone, more common in the deepest and the most shallow parts.

Characteristic species        

Hildenbrandia spp., Pseudolithoderma spp.

Geographic range               

Whole Baltic Sea

Anthropogenic threats     


Correspondence with other classification systems               

HELCOM 1998:

2.8 Mixed sediment bottoms

2.8.2 Sublittoral photic zone by macrophyte vegetation

EUNIS 2012:

A5 Sublittoral sediment

A5.5 Sublittoral macrophyte-dominated sediment