AA.J1B3 Baltic photic sand dominated by watermilfoil (Myriophyllum spicatum and/or Myriophyllum sibiricum)


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with at least 90 % coverage of sand. Sand has less than 20 % of mud/silt/clay fraction (<63 µm), and the proportion of sand (grain size 0.063–2 mm) exceeds 70% of the combined gravel and sand fraction. 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. Out of the submerged rooted plants, watermilfoil  constitutes at least 50 % of the biovolume.

Physical environment       

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

Characteristic species        

Myriophyllum spicatum, Myriophyllum sibiricum


Whole Baltic Sea

Anthropogenic threats

Decreased light penetration depth and increased sedimentation caused by eutrophication

Correspondence with other classification systems               

HELCOM 1998:

2.5 Sandy bottoms

2.5.2 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