AA.A1H Baltic photic rock and boulders characterized by epibenthic moss animals (Bryozoa)


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with at least 90 % coverage of rock, boulders or stones of more than 63 mm in diameter. Sessile/semi-sessile epibenthic moss animals cover at least 10 % of the seabed and more than other perennial attached erect groups.

Physical environment       

Salinity range: All; Exposure range: all, more common in exposed areas; Depth range: photic zone

Characteristic species        

Electra crustulenta, Flustra foliacea

Mapping advise (habitat delineation, identification, similar types)             

Moss animals can live as epiphytes (e.g. Electra crustulenta on Fucus spp.). In the BSEUNIS classification epiphytes are considered to be quality descriptors, not habitat forming.

Quality descriptors             

Diversity, abundance and biomass of fauna.

Geographic range               

Whole Baltic Sea

Anthropogenic threats     


Correspondence with other classification systems               

HELCOM 1998:

2.1 Rocky bottoms

2.1.1 Soft rock Sublittoral photic zone

2.1.2 Solid rock (bedrock) Sublittoral photic zone

2.2 Stony bottoms

2.2.2 Sublittoral photic zone

EUNIS 2012:
A3.4 : Baltic exposed infralittoral rock
A3.5 : Baltic moderately exposed infralittoral rock
A3.6 : Baltic sheltered infralittoral rock