AA.J3 Baltic photic sand characterized by macroscopic infaunal biotic structures

Author

HELCOM RED LIST Biotope Expert Team

Textual description

Baltic bottoms in the photic zone 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. Macroscopic infauna present, no macrovegetation or epibenthic macrofauna.

Physical environment

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

Characteristic species

Bathyporeia pilosa, Arenicola marina, Macoma balthica, Mya arenaria, Cyathura carinata

Mapping advise (habitat delineation, identification, similar types)

Photic zone areas with pure sand, often characterized by ripple marks. Sediment must contain less than 20 % of mud/silt/clay fraction (<63 µm), and more than 70 % of sand (grain size 0.063–2 mm ). Macroscopic infauna present, no macrovegetation or epibenthic macrofauna.

Quality descriptors

Soft sediment covering the sand will decrease the quality.

Geographic range

Whole Baltic Sea

Anthropogenic threats

Silting caused by eutrophication, dredging spoil deposition etc.

Correspondence with other classification systems

HELCOM 1998:

2.5 Sandy bottoms

2.5.2 Sublittoral photic zone

2.5.2.1 Level bottoms with little or no macrophytevegetation

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