AB.A1 Baltic aphotic rock and boulders characterized by macroscopic epibenthic biotic structures


Author                                     

HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the aphotic zone with at least 90 % coverage of rock, boulders or stones of more than 63 mm in diameter. Coverage of sessile macroscopic epifauna is≥10%.

Physical environment       

Salinity range: all; Exposure range: all; Depth range: below photic zone ‑ more common in the shallow.

Characteristic species        

Mytilus spp., Cordylophora caspia, Hydrozoa,Amphibalanus improvisus, Bryozoa, Porifera, Hydrozoa

Areas with at least 90 % coverage of rock, boulders and/or stones of more than 63 mm in diameter within the aphotic zone. Coverage of sessile macroscopic epifauna is ≥10%.

Geographic range               

Whole Baltic Sea

Correspondence with other classification systems               

HELCOM 1998:
2.1Rocky bottoms

2.1.1Aphotic zone

2.2Stony bottoms

2.2.1 Aphotic zone

Habitat types generally associated in the field                       

AB.B1