Epifaunal communities on Baltic infralittoral rock and mixed substrata (predominantly hard)
_(1).jpg "HELCOM RED LIST Biotope Expert Team 2013 and Baltic Sea Working Group for the European Red List of Habitats 2014 and 2015.")
_(2).jpg "HELCOM RED LIST Biotope Expert Team 2013 and Baltic Sea Working Group for the European Red List of Habitats 2014 and 2015.")
Quick facts
| Red List habitat type | code BAL7 |
|---|---|
| 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 rock, boulders or stones and mixed (predominantly hard), according to the HELCOM HUB classification. Eleven associated biotopes have been identified dominated (at least 50% of the biomass) by either epibenthic bivalves, chordates, cnidarians, bryozoans, crustaceans or sponges. They are typically present in a depths of between 2-20 meters but have varying distributions depending on salinity and exposure. For example those biotopes where Mytilidae such as Mytilus spp. or Modiolus modiolus dominate typically occur in depths of 5 – 20 meters, in all exposure classes and in salinities over 5 psu. Biotopes dominated by the mussel Dreissena polymorpha (AA.A1E2/AA.M1E2) usually occupy a depth zone of between 2 – 10 meters, in sheltered to moderate exposure and in salinities less than 5 psu. They occur in the eastern parts of the Gulf of Finland and along the Estonian west coast. ‘Baltic photic rock and boulders/mixed sediment dominated by erect moss animals (Flustra foliaceae)’ (AA.A1H2/AA.M1H2) is found only in western and southwestern Baltic Sea due to salinity constraints (15 psu).
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 the dominate species and associated fauna are potential indicators of quality of this habitat
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 all the associated Baltic biotopes as Least Concern (A1) except for those dominated by the bryozoan Flustra foliacea (AA.A1H2 and AA.M1H2) which were assessed as Near Threatened (A1). With no additional information on changes in extent or quality of this habitat, and because the biotopes assessed as Near Threatened by HELCOM are less common than the other biotopes, current expert opinion is that this habitat should be assessed as Least Concern for 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
Pressures and threats
- 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)
- 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 hunting, taking and fishing and species management
- Regulation/Management of fishery in marine and brackish systems
- Measures related to urban areas, industry, energy and transport
- Urban and industrial waste management
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 sub-basins. |
| EU28+ | >50 | Unknown | This habitat is present in all the Baltic sub-basins |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
