AB.J3L11 Baltic aphotic sand dominated by multiple infaunal polychaete species including Ophelia spp and Travisia forbesii


HELCOM RED LIST Biotope Expert Team

Textual description 

Baltic aphotic 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 bivalves dominates and is highest in the group that includes infaunal bivalves/polychaetes/crustaceans/echinoderms/insect larvae. Ophelia spp. and Travisia forbesi constitute ≥10 % of the macroinfaunal biomass when disregarding the biomass of bivalves.

Characteristic species        

Ophelia spp., Travisia forbesii

Quality descriptors

Diversity, abundance and biomass of fauna

Geographic range

Kiel bight to Darss sill

Correspondence with other classification systems               

HELCOM 1998:

2.5 Sandy bottoms

2.5.1 Aphotic zone

EUNIS 2012:

A5 Sublittoral sediment

A5.2 Sublittoral sand

A5.27 Deep circalittoral sand

A5.273 Baltic sandy bottoms of the aphotic zone


 Related Information

This biotope has been listed as Near Threatened (NT) in the HELCOM Red List of Baltic Sea biotopes and habitats.

See the Biotope Information Sheet of AB.J3L11