AA.A1C Baltic photic rock and boulders characterized by perennial algae


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. Perennial attached algae 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 usually down from about 0.5 meters

Characteristic species        

Fucus spp., Furcellaria lumbricalis, Coccotylus truncatus, Deleseria sanguinea,Polysiphonia spp, Cladophora rupestris, Sphacelaria spp.

Mapping advise (habitat delineation, identification, similar types)             

In areas of low salinity, the dominating species can be plants with their roots between and their canopy spreading over the boulders. Mapping should take place during the months when the vegetation is fully developed.

Quality descriptors            

Lower limit of vegetation, especially Fucus spp. where applicable; amount of epiphytic algae

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 Level bottoms dominated by macrophytevegetation

2.1.2 Solid rock (bedrock) Sublittoral photic zone Level bottoms dominated by macrophytevegetation

2.2 Stony bottoms

2.2.2 Sublittoral photic zone Level bottoms dominated by macrophyte


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