AA.H1B Baltic photic muddy sediment characterized by submerged rooted plants


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). Submerged rooted plants, including plants with rhizoids (i.e. Charales) cover at least 10 % of the seabed and more than other perennial attached erect groups.

Physical environment       

Substrate is muddy sediment. Salinity range: all; Exposure range: sheltered; Depth range: photic zone

Characteristic species        

Stuckenia pectinata, Myriophyllum spicatum, Najas marina, Chara tomentosa

Geographic range               

Whole Baltic Sea

Anthropogenic threats     


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