Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA3.34 Submerged fucoids, green or red seaweeds on low salinity Atlantic infralittoral rock

Submerged fucoids, green or red seaweeds on low salinity Atlantic infralittoral rock

Quick facts

Red List habitat type code NEAA3.34
Threat status
Europe Data Deficient
EU Data Deficient
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

Very shallow submerged rocky habitats in bays, inlets or estuaries subject to permanently reduced salinity conditions. These particular conditions lead to a variety of seaweed-dominated communities, which include fucoids, green and red macroalgae species. The fucoids, more typical of intertidal Atlantic habitats, penetrate into the subtidal under the reduced salinity conditions which are not tolerated by kelps. This habitat may also includes dense stands of Ascophyllum nodosum if salinities are high enough (>20psu).

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. Dominance of fucoids (cover or biomass ratios of fucoids to other macroalgae) or penetration of fucoids along the salinity gradient is used in some countries as a Water Framework Directive parameter for assessing ecological status.

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

Threat status

Synthesis of Red List assessment

This habitat does not have a restricted geographical distribution however it may have a restricted Area of Occupancy. There is insufficient information to determine any overall trends in quantity or quality in the North East Atlantic
The current Red List assessment is that although AOO is less than 50, this habitat qualifies as Data Deficient because of incomplete information on its area, and any trends in quantity and quality.
EU
Red List Category Red List Criteria
Data Deficient -
Europe
Red List Category Red List Criteria
Data Deficient -

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Other urbanisation, industrial and similar activities
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
  • Natural System modifications
    • Human induced changes in hydraulic conditions

Habitat restoration potential

The capacity for this habitat to recover after being severly damaged is unknown.

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

Regulation of coastal construction and maintenance of good water quality will benefit this habitat. Inclusion within Marine Protected Areas and identification in spatial planning documents can also raise awareness about the biodiversity interest of this habitat and specify measures to prevent degradation and loss. There may be some scope for habitat restoration by opening up or removing any barriers to water movement that have altered the salinity regime.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to marine habitats
    • Restoring marine habitats
  • Measures related to spatial planning
    • Other marine-related measures
    • Establish protected areas/sites

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 Unknown
Celtic Seas
Greater North Sea
Kattegat

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 193,333 >30 Unknown EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the threshold for threatened status for EOO.
EU28+ >30 Unknown EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the threshold for threatened status for EOO.
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 Ascophyllum nodosum
Algae Chondrus crispus
Algae Chorda filum
Algae Cladophora rupestris
Algae Fucus ceranoides
Algae Fucus serratus
Algae Fucus vesiculosus
Algae Furcellaria lumbricalis
Algae Mastocarpus stellatus
Algae Polyides rotundus
Invertebrates Actinia equina
Invertebrates Anemonia viridis
Invertebrates Arenicola marina
Invertebrates Ascidiella aspersa
Invertebrates Ascidiella scabra
Invertebrates Asterias rubens
Invertebrates Carcinus maenas
Invertebrates Ciona intestinalis
Invertebrates Clavelina lepadiformis
Invertebrates Mytilus edulis
Invertebrates Pagurus bernhardus
Species scientific name English common name Species group
Ascophyllum nodosum Algae
Chondrus crispus Algae
Chorda filum Algae
Cladophora rupestris Algae
Fucus ceranoides Algae
Fucus serratus Algae
Fucus vesiculosus Algae
Furcellaria lumbricalis Algae
Mastocarpus stellatus Algae
Polyides rotundus Algae
Actinia equina Invertebrates
Anemonia viridis Invertebrates
Arenicola marina Invertebrates
Ascidiella aspersa Invertebrates
Ascidiella scabra Invertebrates
Asterias rubens Invertebrates
Carcinus maenas Invertebrates
Ciona intestinalis Invertebrates
Clavelina lepadiformis Invertebrates
Mytilus edulis Invertebrates
Pagurus bernhardus Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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1050 Copenhagen K
Denmark
Phone: +45 3336 7100