AA.H Baltic photic muddy sediment


HELCOM RED LIST Biotope Expert Team

Textual description

Baltic bottoms in the photic zone 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 ┬Ám).

Physical environment

Salinity range: all; Exposure range: sheltered; Depth range: photic zone

Characteristic species

Phanerogams, Charales, mobile epifauna, infauna

Mapping advise (habitat delineation, identification, similar types)

Photic zone areas with muddy sediment, such as soft clay, silt or mud. This includes mixed sediments where clay and/or mud are mixed with sand or gravel.

Geographic range

Whole Baltic Sea

Anthropogenic threats

Silting caused by eutrophication, dredging spoil deposition etc.

Correspondence with other classification systems

HELCOM 1998:
2.7 Muddy bottoms

2.7.2 Sublittoral photic zone

EUNIS 2012:

A5 Sublittoral sediment

A5.3 Sublittoral mud

A5.31 Sublittoral mud in low or reduced salinity

A5.311 Baltic brackish water sublittoral muddy biocenoses influenced by varying salinity