Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA1.12 Robust fucoid and/or red seaweed communities on wave-exposed Atlantic littoral rock

Robust fucoid and/or red seaweed communities on wave-exposed Atlantic littoral rock

Quick facts

Red List habitat type code NEAA1.12
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 habitat occurs on extremely exposed to moderately exposed upper to lower shores with seaweeds that are able to tolerate the extreme conditions of exposure. The physical stresses caused by wave action often results in dwarf forms of the individual seaweeds. The strong holdfasts and short tufts structure of the wracks Fucus distichus and Fucus spiralis f. nana allow these fucoids to survive on extremely exposed shores. Another seaweed able to tolerate the wave-wash is the red seaweed Corallina officinalis, which can form a dense turf on the mid- to lower shore. The olive brown wrack Pelvetia canaliculata positioned at the highest points of the intertidal shore, can withstand long periods of exposure. The wrack Himanthalia elongata occurs on the lower shore and can extend on to moderately exposed shores. The red seaweed Mastocarpus stellatus is common on both exposed and moderately exposed shores, where it may form a dense turf (particularly on vertical or overhanging rock faces. Very exposed to moderately exposed lower eulittoral rock can support a pure stand of the red seaweed Palmaria palmata. It is found either as a dense band or in large patches above the main sublittoral fringe.

Two biotopes associated with this habitat are characterised by extensive areas or a distinct band of Osmundea pinnatifida in areas exposed to moderately exposed lower eulittoral rock, and outcrops of fossilised peat in the eulittoral that are soft enough to allow a variety of piddocks, such as Barnea candida and Petricola pholadiformis, to bore into them.

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. Long term loss of the characteristic fucoids and/or red algae would indicate a deterioration in quality. 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 abundance and coverage of the rocky surfaces by typical species. 

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

Threat status

Synthesis of Red List assessment

This habitat has a large natural range in the North East Atlantic region, extending from the Canaries and Azores in the west to the Skagerrak coast of Sweden in the east. Local and/or seasonal factors often exert a substantial influence on intertidal habitats making it difficult to distinguish any long-term trend across the region. This is complicated further because differences between localities are often linked to differences in geographical latitude and, therefore, to differences in climatic traits such as temperature and/or ice cover.
There are studies showing short and long term trends in extent and quality in some locations, for example following natural events such as severe weather conditions or pollution incidents such as oil spills however expert opinion is that the extent of this habitat has most likely been stable over the last 50 years. Trends in quality are unknown. The nature and size of threats to this habitat, and the distribution data which are available, suggest that known threats are unlikely to affect all localities at once. This habitat has therefore been assessed as Least Concern for both 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

low
Red List of habitat categories and criteria descriptions

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

Generally, the effects of chronic impacts on this habitat are reversible provided the disturbance is stopped. Recovery from acute impacts is also possible but may take much longer depending on the scale and type of impact.

Trends in extent

Average current trend in quantity

Stable Stable
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

There are limited opportunities and need for specific conservation and management measures directed at this habitat. 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
    • Establish protected areas/sites
    • Legal protection of habitats and species

Distribution

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)
Bay of Biscay and the Iberian Coast Present unknown Unknown 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 320,274 267 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+ 267 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.
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

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Algae Cladophora rupestris
Algae Corallina officinalis
Algae Enteromorpha intestinalis
Algae Fucus distichus
Algae Fucus spiralis
Algae Himanthalia elongata
Algae Laminaria digitata
Algae Lomentaria articulata
Algae Mastocarpus stellatus
Algae Osmundea pinnatifida
Algae Palmaria palmata
Algae Pelvetia canaliculata
Algae Ulva lactuca
Algae Ulva rigida
Invertebrates Barnea candida
Invertebrates Halichondria panicea
Invertebrates Megabalanus azoricus
Invertebrates Mytilus edulis
Invertebrates Nucella lapillus
Invertebrates Patella vulgata
Invertebrates Petricola pholadiformis
Invertebrates Semibalanus balanoides
Species scientific name English common name Species group
Cladophora rupestris Algae
Corallina officinalis Algae
Enteromorpha intestinalis Algae
Fucus distichus Algae
Fucus spiralis Algae
Himanthalia elongata Algae
Laminaria digitata Algae
Lomentaria articulata Algae
Mastocarpus stellatus Algae
Osmundea pinnatifida Algae
Palmaria palmata Algae
Pelvetia canaliculata Algae
Ulva lactuca Algae
Ulva rigida Algae
Barnea candida Invertebrates
Halichondria panicea Invertebrates
Megabalanus azoricus Azorean barnacle Invertebrates
Mytilus edulis Invertebrates
Nucella lapillus Dog whelk Invertebrates
Patella vulgata Invertebrates
Petricola pholadiformis Invertebrates
Semibalanus balanoides Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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