AA.J3M2 Baltic photic sand dominated by lugworms (Arenicola marina)


HELCOM RED LIST Biotope Expert Team

Textual description 

Baltic photic zone bottoms 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. Biomass of infaunal polychaetes dominates and is highest in the group that includes infaunal bivalves/polychaetes/crustaceans/echinoderms/insect larvae. Out of the infaunal polychaetes Arenicola marina constitutes at least 50 % of the biomass.

Physical environment       

Substrate is sand. Depth is typically from 1 to 5 meters, Appears in from low to high wave exposure. Salinity >10 psu

Characteristic species        

Arenicola marina, Mya arenaria, Cerastoderma sp.

Quality descriptors

Diversity, abundance and biomass of fauna.


Western Baltic Sea

Correspondence with other classification systems               

HELCOM 1998:

2.5 Sandy bottoms

2.5.2 Sublittoral photic zone Level bottoms with little or no macrophyte


EUNIS 2012:

A5 Sublittoral sediment

A5.2 Sublittoral sand

A5.21 Sublittoral sand in low or reduced salinity

A5.211 Baltic level sandy bottoms of the infralittoral photic zone with little or no macrophyte vegetation