AA.I1B6 Baltic photic coarse sediment dominated by Ranunculus spp.


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, Ranunculus spp. constitutes at least 50 % of the biovolume.

Physical environment       

Salinity range: >6 psu; Exposure range: moderate to high; Depth range: photic zone from about 1 to 7 meters.

Characteristic species        

Ranunculus spp.


Whole Baltic Sea

Anthropogenic threats   


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

A5.543 Vegetation of brackish waters dominated by [Ranunculus baudotii]