AA.I1Q2 Baltic photic coarse sediment dominated by stable aggregations of unattached Fucus spp. (typical form)


Author                                     

HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic bottoms in the photic zone with at least 90 % coverage of coarse sediment. Coarse sediment has less than 20 % of mud/silt/clay fraction (<63 µm), and the proportion of gravel and pebbles (grain size 2–63 mm) exceeds 30% of the combined gravel and sand fraction . No perennial attached erect group has a coverage ≥ 10%. Stable aggregations of unattached perennial vegetation covers at least 10 %, out of which Fucus spp. (dwarf form) constitutes at least 50 % of the biovolume.

Physical environment       

Salinity range: >4.5 psu; Exposure range: sheltered to exposed; Depth range: photic zone from about 0.5 to 5 meters

Characteristic species        

Fucus vesiculosus dwarf form (synonym f.pygmaea)

Geographical RAnge

Known from Swedish and German coasts

ANTHROPOGENIC THREATS

Decreased light penetration depth and increased sedimentation caused by eutrophication.

Correspondence with other classification systems               

HELCOM 1998:

2.4 Gravel bottoms

2.4.2 Sublittoral photic zone

2.4.2.2 Level bottoms dominated by macrophyte vegetation

EUNIS 2012:

A5 Sublittoral sediment

A5.5 Sublittoral macrophyte-dominated sediment

http://eunis.eea.europa.eu/habitats/1733

 Related Information

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

See the Biotope Information Sheet of AA.I1Q2

 Publications

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