HELCOM RED LIST Biotope Expert Team
aphotic zone bottoms with at least 10- 90 % coverage of hard (rock/boulders/stone)
and 10-90 % soft substrata (e.g. muddy/coarse sediment/sand). Epibenthic
bivalves cover at least 10 % of the seabed, and more than other perennial
attached erect groups. Out of the epibenthic bivalves, Mytilidae constitutes at
least 50 % of the biomass.
is soft or crystalline rock, boulders or stones mixed with mobile substrates
such as sand or coarse substrate. Depth is typically from 20 to 100 meters.
Appears in all wave exposure classes. Salinity >5 psu.
Mytilus spp. and Modiolus modiolus
of sediment. Diversity, abundance and biomass of fauna
Sea up to the Quark in the North
2.8 Mixed sediment bottoms
2.8.1 Aphotic zone
A5 Sublittoral sediment
A5.4 : Sublittoral mixed sediments
A5.41 : Sublittoral mixed sediment in low or reduced salinity
A5.412 : Baltic mixed sediment bottoms of the aphotic zone
OSPAR list of threathened biotopes:
Modiolus modiolus beds
Habitat occurs in the OSPAR Region II (including Kattegat) and is listed threatened and/or declining in this region
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