Epibenthic communities in Baltic upper circalittoral mixed sediment
Quick facts
| Red List habitat type | code BAL49 |
|---|---|
| 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 is a Baltic Sea benthic habitat in the aphotic zone. The substrate is a mix of soft or crystalline rock, boulders or stones mixed with mobile substrates such as sand or coarse substrate as well as muddy sands as defined in the HELCOM HUB classification. It typically occurs in depths from 20-150m and seven associated biotopes have been described, some of which are more common in particular depth zones. The biotopes are variously characterised by epibenthic bivalves, chordates, cnidarians (soft corals and sea anemones), bryozoans, crustaceans, sponges and a mixed epibenthic macrocommunity. Some occur in all the sub-basins of the Baltic Sea whereas as others, such as aphotic mixed substrates characterised by epibenthic sponges, are only reported from the Belt Sea and the Gulf of Bothnia. Depending on the dominant species the biotope may either be encrusting or form a layer of living material extending 20cm about the substrate.
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. Diversity, abundance and biomass of fauna are potential indicators of quality.
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 four of the associated biotopes as NT(A1), and four as LC(A1). One further biotope was not evaluated. On the basis of these assessments and expert opinion, this habitat is assessed as Near Threatened, since there has been an estimated 10-30% decline in quantity over the last 50 years.
| 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
- Mining, extraction of materials and energy production
- Mining and quarrying
- Sand and gravel extraction
- Exploration and extraction of oil or gas
- Biological resource use other than agriculture & forestry
- Fishing and harvesting aquatic resources
- Professional active fishing
- Benthic or demersal trawling
- Benthic dredging
- 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
Habitat restoration potential
Trends in extent |
|
Average current trend in quantity |
|
Decreasing  |
Decreasing |
| 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
- Establish protected areas/sites
- Measures related to hunting, taking and fishing and species management
- Regulation/Management of fishery in marine and brackish systems
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 | Decreasing |
| 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 | 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. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
Characteristic species
Legal status
Relation to other habitat types mentioned in legal instruments
| Legal text | Annex | Name in legal text | Code in legal text |
Habitat type relationship |
More information |
|---|---|---|---|---|---|
| Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007 | Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation | Large shallow inlets and bays | 1160 | Overlap | http://ec.europa.eu/environm...rective/index_en.htm |
