AA.A1 Baltic photic rock and boulders characterized by macroscopic epibenthic biotic structures


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. At least 10 % coverage of macroscopic vegetation or sessile macroscopic epifauna?

Physical environment

Salinity range: All; Exposure range: all, More common in exposed areas; Depth range: Photic zone ‑ more common in shallow areas.

Characteristic species

Cladophora spp., Ceramium spp., Laminaria sp., Fucus sp., Furcellaria lumbricalis, Polysiphonia fucoides, Aegogrophila linnaei, Fontinalis sp. Ascidiaceae, Electra crustulenta, Flustra foliacea, Balanidae, Mytilus spp., Modiolus modiolus

Mapping advise (habitat delineation, identification, similar types)

Macroscopic vegetation or sessile macroscopic epifauna cover at least 10 % of the substrata. In areas of low salinity, the dominating species can be plants with their roots between and their canopy spreading over the boulders.

Quality descriptors

Lower limit, 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 vegetation

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