AA.E1F1 Baltic photic shell gravel dominated by vase tunicate (Ciona intestinalis)


HELCOM RED LIST Biotope Expert Team

Textual description            

Baltic photic bottoms at least 90 % coverage of shell gravel. Epibenthic chordates cover at least 10% of the seabed,and more than other attached erect groups. Out of the epibenthic chordates, Vase tunicate (Ciona intestinalis) constitutes at least 50 % of the biomass.

Physical environment       

Substrate is shell gravel.

Characteristic species        

Ciona intestinalis

Geographic range               

Known from German waters in the Baltic Sea

Anthropogenic threats     

Increase in atmospheric CO2 (Ocean acidification)

Correspondence with other classification systems               

HELCOM 1998:

2.6 Shell gravel bottoms

2.6.2Shell gravel bottoms in sublittoral photic zone

HELCOM 2007:

Shell gravel bottoms

  • habitat under threat and/or in decline in all areas of occurrence: The Southern Baltic Proper, The Gulf of Gdansk, Bay of Mecklenburg, Kiel Bay, Little Belt, Great Belt, The Sound, Kattegat

EUNIS 2012:

A5 Sublittoral sediment

A5.1 Sublittoral coarse sediment

A5.11 Infralittoral coarse sediment in low or reduced salinity

A5.113 : Baltic shell gravel bottoms in the infralittoral photic zone

 Related information

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

See the Biotope Information Sheet of AA.E1F1