AA.M1H1 Baltic photic mixed substrate dominated by crustose moss animals (Electra crustulenta)


HELCOM RED LIST Biotope Expert Team

Textual description 

Baltic photic bottoms with 10- 90 % coverage of hard (rock/boulders/stone) and 10-90 % soft substrata (e.g. muddy/coarse sediment/sand). Epibenthic moss animals cover at least 10%of the seabed and more than other perennial attached erect groups. Out of the epibenthic moss animals, crustose moss animals constitute at least 50 % of the biomass.

Physical environment       

Substrate is soft or crystalline rock, boulders or stones mixed with mobile substrates such as sand or coarse substrate.

Characteristic species  

Electra crustulenta  

Quality descriptors

Diversity, abundance and biomass of fauna


Whole Baltic Sea

Correspondence with other classification systems

HELCOM 1998:
2.8 Mixed sediment bottoms

2.8.2 Sublittoral photic zone With little or no macrophyte vegetation

EUNIS 2012:

A5 Sublittoral sediment

A5.4 : Sublittoral mixed sediments

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

A5.411 : Baltic level mixed sediment bottoms of the infralittoral photic zone with little or no macrophyte vegetation