Red List habitat classification > RL - Marine habitats > RLBAL - Baltic > BAL60 Sparse or no macrocommunities of Baltic upper circalittoral muddy sediment

Sparse or no macrocommunities of Baltic upper circalittoral muddy sediment

Quick facts

Red List habitat type code BAL60
Threat status
Europe Near Threatened
EU Near Threatened
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


This Baltic Sea benthic habitat occurs in the aphotic zone in areas 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 μm). The associated biotope is : ‘Baltic aphotic muddy sediment dominated by meiofauna (AB.H4U1) although when degraded this may be represented by ‘Baltic aphotic muddy sediment dominated by anerobic organisms (AB.H4U2). The balance between the two depends on whether conditions are aerobic or anerobic and deterioration in the former biotope may result in the habitat being dominated by the latter (anerobic) biotope more typical of degraded conditions. 

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.

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

Threat status

Synthesis of Red List assessment

In the coastal zone there has been some deterioration in the extent and quality of this habitat due to increased sedimentation and eutrophication as a result of coastal development and increased levels of N, P and organic matter. Further offshore where anoxic conditions are more naturally prevalent, there has been some increase in the habitat extent. Overall there is a lack of quantitative information in changes in distribution, extent and quality of this habitat but expert opinion considers there to have been a decline in extent in the range of 25-35% of aphotic sediment dominated by meiofauna over the last 50 years .
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 the associated Baltic biotopes (AB.H4U1) as Near Threatened (A1). With no additional information on changes in extent or quality of this habitat, and due to the overall decline in quantity of this habitat current expert opinion is that this habitat should be assessed as Near Threatened for both the EU 28 and EU 28+.
Red List Category Red List Criteria
Near Threatened A1
Red List Category Red List Criteria
Near Threatened A1

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Urbanised areas, human habitation
    • Other patterns of habitation
  • Human intrusions and disturbances
    • Sport and leisure structures
    • Other sport / Leisure complexes
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Removal of sediments (mud...)
    • Estuarine and coastal dredging
    • Siltation rate changes, dumping, depositing of dredged deposits
    • Dumping, depositing of dredged deposits
    • Other siltation rate changes

Habitat restoration potential


Trends in extent

Average current trend in quantity

Unknown Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

More information is needed on the distribution and ecology of this habitat. Development and construction in the shallow muddy areas along the coast where it occurs should be restricted to maintain the aerobic conditions.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to spatial planning
    • Other marine-related measures
    • Establish protected areas/sites
  • Measures related to special resouce use
    • Regulating/Managing exploitation of natural resources on sea


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 Unknown Unknown
Belt Sea
Gulf of Bothnia
Gulf of Finland
Gulf of Riga
The Sound

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 >50 Unknown This habitat is present in all the Baltic Sea sub-basins.
EU28+ >50 Unknown This habitat is present in all Baltic sub-basins.
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
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