AA.M2W Baltic photic mixed substrate characterized by microphytobenthic organisms and grazing snails


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with more than 10 %, but less than 90 % coverage of both hard and soft substrata. Sessile/semi-sessile macroscopic epibenthic fauna and flora is present but has less than 10 % coverage. Microphytobenthic organisms and grazing snails dominate. Grazing snails (e.g. Hydrobiidae, Theodoxus, Bithynia, Radix) constitute 50 % in biomass or volume

Physical environment       

Salinity range: moderate to high; Exposure range: all; Depth range: photic zone, more common in the deepest and the most shallow parts.

Geographic range               

Whole Baltic Sea

Correspondence with other classification systems               

HELCOM 1998:

2.8 Mixed sediment bottoms

2.8.2 Sublittoral photic zone


EUNIS 2012:

A5 Sublittoral sediment

A5.4 : Sublittoral mixed sediments

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