Mytilus edulis and/or barnacle communities on wave-exposed Atlantic littoral rock
Quick facts
Red List habitat type | code NEAA1.11 |
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Threat status | |
Europe | Least Concern |
EU | Least Concern |
Relation to |
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Source | European Red List habitat factsheet |
European Red List of habitats reports | |
European Red List of habitats (Excel table) |
Summary
This habitat type is found in the mid- to upper eulittoral on shores that are moderately or very exposed to wave action. It is characterised by bedrock and boulders dominated by the mussel Mytilus edulis, barnacles Chthamalus spp. and/or Semibalanus balanoides and limpets Patella spp. There is much regional variation in the species and zonation of the barnacles. Amongst the mussels small red algae including Ceramium shuttleworthianum, Corallina officinalis, Mastocarpus stellatus and Aglaothamnion spp. can be found. Two red algae in particular, Porphyra umbilicalis and Palmaria palmata, are commonly found on the Mytilus itself and can form luxuriant growths.The abundance of the red algae generally increases down the shore and in the lower eulittoral they may form a distinct zone in which mussels or barnacles are scarce. The lichen Lichina pygmaea may be prominent, especially in the south, where it can form distinct patches or even a separate zone among the Chthamalus spp.
With decreasing wave exposure F. vesiculosus is able to survive, gradually replacing the barnacles and P. vulgata biotope. On such moderately exposed shores this habitat may occur on steep and vertical faces, while fucoids dominate the flatter areas. In areas of soft rock (e.g. shales), the barnacles may be scarce or absent and the rock dominated by P. vulgata.
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 overtime.
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. Indicators which have been developed for the assessment of ecological quality of coastal water bodies for the Water Framework Directive (WFD) that are relevant to this habitat include a consideration of macroalgae species richness, proportions of different taxa of algae present , and the abundace and coverage of the rocky surfaces by typical species.
Threat status
Synthesis of Red List assessment
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
- Pollution
- Marine water pollution
- Oil spills in the sea
- Climate change
- Changes in abiotic conditions
- Temperature changes (e.g. rise of temperature & extremes)
- Wave exposure changes
- Sea-level changes
- Changes in biotic conditions
- Habitat shifting and alteration
- Migration of species (natural newcomers)
Habitat restoration potential
Trends in extent |
|
Average current trend in quantity |
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Stable ![]() |
Stable ![]() |
EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
Stable ![]() |
Stable ![]() |
EU28 | EU28+ |
Conservation and management needs
More general beneficial measures include pollution control and regulation, development control and contingency plans to be followed in the event of a major pollution incident, survey and monitoring programmes, raised public awareness of their ecological value and vulnerability, representation in marine protected areas and measures to reduce global warming and sea level rise.
List of conservation and management needs
- Measures related to marine habitats
- Other marine-related measures
- Measures related to spatial planning
- Other marine-related measures
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) |
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Bay of Biscay and the Iberian Coast | Present | unknown | Stable | Stable |
Celtic Seas | ||||
Greater North Sea | ||||
Macaronesia |
Extent of Occurrence, Area of Occupancy and habitat area
Extent of Occurrence (EOO) (Km2) | Area of Occupancy (AOO) | Current estimated Total Area | Comment | |
---|---|---|---|---|
EU28 | 644,989 | 603 | unknown | EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the thresholds for threatened status. |
EU28+ | 603 | unknown | EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the thresholds for threatened status. |
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 |
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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 | Reefs | 1170 | Overlap | http://ec.europa.eu/environm...rective/index_en.htm |