AB.E2 Baltic aphotic shell gravel characterized by sparse macroscopic epibenthic biotic structures


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic aphotic bottoms with at least 90 % coverage of shell gravel. Coverage of sessile macroscopic epifauna is 0><10%.

Physical environment       

Substrate is shell gravel. Depth is typically ? meters. Appears mostly in high energy exposure areas.

Characteristic species        

Mytilus spp., Modiolus modiolus,Ciona intestinalis, Balanidae, Bryozoa

Mapping advise (habitat delineation, identification, similar types)             

Coverage of sessile macroscopic epifauna is 0><10%.

Geographic range               

Southern part of Baltic Sea, the Sound, Kattegat

Anthropogenic threats     

Increase in atmospheric CO2 (Ocean acidification)

Correspondence with other classification systems               

HELCOM 1998:
2.6 Shell gravel bottoms

2.6.1 Aphotic zone

HELCOM 2007:

Shell gravel bottoms

  • habitat under threat and/or in decline in all areas of occurrenc: The Southern Baltic Proper, The Gulf of Gdansk, Bay of Mecklenburg, Kiel Bay, Little Belt, Great Belt, The Sound, Kattegat

EUNIS 2012:

A5 Sublittoral sediment

A5.1 Sublittoral coarse sediment

A5.11 Infralittoral coarse sediment in low or reduced salinity

A5.115 Baltic shell gravel bottoms of the aphotic zone