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) |
Summary
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.
Threat status
Synthesis of Red List assessment
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+.
| EU | |
| Red List Category | Red List Criteria |
| Near Threatened | A1 |
| Europe | |
| Red List Category | Red List Criteria |
| Near Threatened | A1 |
Confidence in the assessment
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
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
Distribution
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. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
