HELCOM RED LIST Biotope Expert Team
aphotic zone bottoms with at least 90 % coverage of muddy sediment. The
sediment must contain at least 20 % of mud, silt or clay (grain size less
than 63 µm). Macrocommunities are not present. Anaerobic organisms
constitute at least 50% of the present biomass.
is muddy sediment. Depth is typically from 50 to 250 meters. Appears in all
wave exposure classes. No O2.
2.7 Muddy bottoms
2.7.1 Aphotic zone
A5 Sublittoral sediment
A5.3 Sublittoral mud
A5.37 Deep circalittoral mud
A5.378 Baltic muddy bottoms of the aphotic zone
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