AA.M1Q4 Baltic photic mixed substrate dominated by stable aggregations of unattached rigid hornwort(Ceratophyllum demersum)


HELCOM RED LIST Biotope Expert Team

Textual description 

Baltic bottoms in the photic zone with more than 10 %, but less than 90 % coverage of both hard and soft substrata. No perennial attached erect group has a coverage ≥ 10 %. Stable aggregations of unattached perennial vegetation covers at least 10 %, out of which unattacher rigid hornwort constitutes at least 50 % of the biovolume.

Physical environment       

Exposure range: extremely sheltered; Depth range: photic zone to about 2 meters

Characteristic species  

Ceratophyllum demersum


Found in sheltered bays.

Correspondence with other classification systems               

HELCOM 1998:

2.8 Mixed sediment bottoms

2.8.2 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