Red List habitat classification > RL - Marine habitats > RLBAL - Baltic > BAL16 Emergent vegetation communities on Baltic infralittoral coarse sediment

Emergent vegetation communities on Baltic infralittoral coarse sediment

Quick facts

Red List habitat type code BAL16
Threat status
Europe Least Concern
EU Least Concern
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

This is a Baltic Sea benthic habitat in the photic zone where at least 90% of the substrate is coarse sediment according to the HELCOM HUB classification. It is found across all salinity ranges in the Baltic and in areas where there is low to moderate exposure to wave action typically to depths of about 2 meters. The associated communities of sedges and/or reeds are more typically found in areas of soft sediment. Their presence on coarse sediment may indicate that siltation is already taking place and that the establishment of sedges and reeds will increase the rate of siltation, changing the substrate to finer sediments over time. 

Two associated biotopes with different dominant plant species have been identified. The common reed (Phragmites australis) forms the charactersitic biotope in water depths of up to 2m and in moderately exposed conditions, where as sedges such as Schoenoplectus spp, Bolbaschoenus maritimus are generally in more sheltered and shallower waters.  Nutrient levels play a part in affecting the balance between the two biotopes with reed dominated areas favoured by conditions of eutrophication. 

Indicators of quality: 

Both biotic and abiotic indicators have been used to describe marine habitat quality. These include: the presence of characteristic species as well as those which are sensitive to the pressures the habitat may face; water quality parameters; levels of exposure to particular pressure, and more integrated indices which describe habitat structure and function, such as trophic index, or successional stages of development in habitats that have a natural cycle of change over time. There are no commonly agreed indicators of quality for this habitat, although particular parameters may have been set in certain situations e.g. protected features within Natura 2000 sites, where reference values have been determined and applied on a location-specific basis. The overall quality and continued occurrence of this habitat is, however, largely dependent on the presence of the emergent plant species which create the biogenic structural complexity on which the characteristic associated communities depend. The density and the maintenance of a viable population of these species is a key indicator of habitat quality, together with thevisual evidence of presence or absence of physical damage. In the case of this habitat the situation is further complicated because the reed dominated biotope is favoured by the deterioration of the sedge dominated biotope under conditions of eutrophication.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

Increases in extent have been evident in this habitat in the last 50 years, though this is mainly due to the increase of reed (Phragmites australis) while at the same time sedges have decreased, most likely a response to eutrophication favouring the former. In the case of the sedge dominated biotopes some loss in density/biomass may be occuring but there are no monitoring data to confirm this.
The overall assessment for this EUNIS level 4 habitat has been based on the HELCOM (2013) assessments for the associated HELCOM HUB biotopes. Draft assessments were derived using a weighted approach whereby the HELCOM assessment outcomes were assigned a score. This was averaged across the relevant biotopes. The outcomes were reviewed by Baltic experts to reach a final conclusion. HELCOM (2013) assessed AA.I1A1 and AA.I1A2 as Least Concern (A1). Expert opinion is that this habitat is either stable or has increased in extent over the last 50 years and therefore should be assessed as Least Concern for both the EU 28 and EU 28+.
EU
Red List Category Red List Criteria
Least Concern -
Europe
Red List Category Red List Criteria
Least Concern -

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
    • Input of contaminants (synthetic substances, non-synthetic substances, radionuclides) - diffuse sources, point sources, acute events
  • Natural System modifications
    • Modification of water flow (tidal & marine currents)
    • Dykes, embankments, artificial beaches, general
    • Sea defense or coast protection works, tidal barrages
  • Climate change
    • Changes in abiotic conditions
    • Wave exposure changes
    • Sea-level changes
    • Changes in biotic conditions
    • Habitat shifting and alteration

Habitat restoration potential

Phragmites is a pioneer species and a strong competitor therefore there is considered to be a good capacity for recovery at least for the reed dominated biotope.

Trends in extent

Average current trend in quantity

Increasing Increasing
EU28 EU28+

Trends in quality

Average current trend in quality

Stable Stable
EU28 EU28+

Conservation and management needs

In some areas, there is an active programme of reed removal to encourage re-establishement of the sedge dominated biotopes. Improvements in water quality are also beneficial although it should be noted that whereas increased eutrophication leads to reed replacing sedges, a later decrease in eutrophication does not necessarily facilitate a process where sedges come back.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
  • Measures related to marine habitats
    • Other marine-related measures

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

Seas Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Baltic Proper Present Unknown Stable Increasing
Gulf of Bothnia
Gulf of Finland
Gulf of Riga
The Sound
Belt Sea

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 >50,000 Unknown Unknown This habitat is present in all the Baltic sub-basins however there is insufficient information for accurate calculation of EOO and AOO.
EU28+ Unknown Unknown This habitat is present in all the Baltic sub-basins however there is insufficient information for accurate calculation of EOO and AOO.
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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1050 Copenhagen K
Denmark
Phone: +45 3336 7100