AA.H1A2 Baltic photic muddy sediment characterized by sedges (Cyperaceae)


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with at least 90 % coverage of muddy sediment. The sediment must contain at least 20 % of mud, silt or clay (grain size less than 63 ┬Ám). Emergent vegetation covers least 10 % of the seabed and more than other perennial attached erect groups. Of the emergent vegetation, sedges form at least 50 % in biovolume.

Physical environment       

Salinity range: <5 psu; Exposure range: sheltered; Depth range: photic zone down to about 1 meters.

Characteristic species        

Schoenoplectus spp, Bolbaschoenus maritimus

Geographic range               

Whole Baltic Sea

Correspondence with other classification systems               

HELCOM 1998:
2.7 Muddy bottoms

2.7.2 Sublittoral photic zone Dominated by macrophyte vegetation

EUNIS 2012:

A5 Sublittoral sediment

A5.5 Sublittoral macrophyte-dominated sediment

A5.54 Angiosperm communities in reduced salinity


 Related information

This biotope has been listed as Near Threatened (NT) in the HELCOM Red List of Baltic Sea biotopes and habitats.

See the Biotope Information Sheet of AA.H1A2