AB.M Baltic aphotic mixed substrate


HELCOM RED LIST Biotope Expert Team

Textual description

Baltic bottoms in the aphotic zone with less than 90 % coverage of a certain substrate type. Mixed substrates comprise any proportion of mix of any substrate type of soft/mobile and/or hard/non-mobile substrates.

Physical environment

Salinity range: All; Exposure range: All; Depth range: Below photic zone ‑ more common on elevations.

Characteristic species

Blue mussels (Mytilus spp.), hydroids (Hydrozoa), Baltic tellin (Macoma balthica)

Mapping advise (habitat delineation, identification, similar types)

Aphotic zone areas which form a mosaic of both hard and soft substrata

Geographic range

Whole Baltic Sea

Correspondence with other classification systems

HELCOM 1998:

2.8 Mixed sediment bottoms

2.8.1 Aphotic zone

EUNIS 2012:

A5 Sublittoral sediment

A5.4 : Sublittoral mixed sediments

A5.41 : Sublittoral mixed sediment in low or reduced salinity

A5.412 : Baltic mixed sediment bottoms of the aphotic zone