AA.I1B1 Baltic photic coarse sediment dominated by pondweed Potamogeton perfoliatus and/or Stuckenia pectinata


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with at least 90 % coverage of coarse sediment. Coarse sediment has less than 20 % of mud/silt/clay fraction (<63 µm), and the proportion of gravel and pebbles (grain size 2–63 mm) exceeds 30% of the combined gravel and sand fraction . Submerged rooted plants cover at least 10 % of the seabed and more than other perennial attached erect groups. Of the submerged rooted plants, pondweed constitutes at least 50 % of the biovolume.

Physical environment       

Salinity range: <6 psu; Exposure range: sheltered; Depth range: photic zone from about 0.2 to 4 meters.

Characteristic species        

Potamogeton perfoliatus, Stuckenia pectinata


Whole Baltic Sea

Correspondence with other classification systems               

HELCOM 1998:
2.4 Gravel bottoms

2.4.2 Sublittoral photic zone Level bottoms dominated by macrophyte vegetation

EUNIS 2012:

A5 Sublittoral sediment

A5.5 Sublittoral macrophyte-dominated sediment

A5.54 Angiosperm communities in reduced salinity

A5.542 Association with [Potamogeton pectinatus]