Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA3.11 Kelp with cushion fauna and/or foliose red seaweeds on wave-exposed Atlantic infralittoral rock

Kelp with cushion fauna and/or foliose red seaweeds on wave-exposed Atlantic infralittoral rock

Quick facts

Red List habitat type code NEAA3.11
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

This is a rocky habitat occurring in the infralittoral zone in areas exposed or extremely exposed wave action and/or strong tidal streams. It typically occurs from low water to depths of up to 45m. The rock supports a community of kelp Laminaria hyperborea or further south Laminaria ochroleuca, with foliose seaweeds and animals, the latter tending to become more prominent in areas of strongest water movement. In extremely wave exposed conditions, the sublitttoral fringe is characterised by dabberlocks Alaria esculenta  which, may extends from 5 to 10 m depth, or even replace L. hyperborea as the dominant kelp in the infralittoral zone. The depth to which the kelp extends varies according to water clarity, exceptionally (e.g. St Kilda, Scotland) reaching 45 m. The shallowest kelp plants are often short or stunted, while deeper plants are taller with heavily epiphytised stipes with foliose red seaweeds. At some sites the red seaweeds can be virtually mono-specific, while at other sites show considerable variation, containing a dense mixed turf of a large variety of species. 

The faunal and floral understorey is generally rich in species due, in part, to the relatively low urchin-grazing pressure in such shallow exposed conditions. As the exposure increases the rock surface is covered by a dense turf of anthozoans such as Sagartia elegansPhellia gausapata and Corynactis viridis, encrusting sponges and coralline algae. The gastropod Margarites helicinus can be found grazing on the kelp fronds, whereas the crab Cancer pagurus can be found among the kelp stipes. The bryozoan Tubularia indivisa also occurs, but it does not form such a dense turf as in more shallow waters, while the ascidian Botryllus leachi is found encrusting the large brown seaweeds. Cryptopleura ramosa is the dominant red seaweed on horizontal surfaces. Winter storms may remove patches of kelp, and fast-growing annuals may form a temporary forest

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.

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

Threat status

Synthesis of Red List assessment

Detailed information on the abundance and extent of this habitat is lacking, but it is known to have a widespread distribution. There is also a lack of data on the quantity and quality of this habitat, including any historical or recent, trends across the region.
This habitat has a large EOO and AOO, and therefore qualifies as Least Concern under criterion B. However the habitat is assessed as Data Deficient both at the EU 28 and EU 28+ levels because of the lack of 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

  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
  • Climate change
    • Changes in biotic conditions
    • Migration of species (natural newcomers)

Habitat restoration potential

Perennial species of kelp have a fast recovery potential but in North West Spain, where increased sea surface temperatures led to significant loss, recovery of L.ochroleuca forest was only observed at depth four years after a decline in both shallow and deeper waters.

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

The main approach to the conservation of this habitat is through regulation of the harvesting of kelp. Measures to combat the effects of climate change (sea temperature and sea level rise) will also be beneficial.

List of conservation and management needs

  • Measures related to marine habitats
    • Other marine-related measures
  • 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

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
Macaronesia
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 1,921,515 224 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+ >224 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 Alaria esculenta
Algae Callophyllis laciniata
Algae Corallina officinalis
Algae Cryptopleura ramosa
Algae Delesseria sanguinea
Algae Dictyota dichotoma
Algae Kallymenia reniformis
Algae Laminaria hyperborea
Algae Laminaria ochroleuca
Algae Mastocarpus stellatus
Algae Palmaria palmata
Algae Phycodrys rubens
Algae Plocamium cartilagineum
Invertebrates Alcyonium digitatum
Invertebrates Asterias rubens
Invertebrates Botryllus leachi
Invertebrates Cancer pagurus
Invertebrates Caryophyllia smithii
Invertebrates Corynactis viridis
Invertebrates Echinus esculentus
Invertebrates Electra pilosa
Invertebrates Halichondria panicea
Invertebrates Margarites helicinus
Invertebrates Membranipora membranacea
Invertebrates Nucella lapillus
Invertebrates Obelia geniculata
Invertebrates Pachymatisma johnstonia
Invertebrates Patella vulgata
Invertebrates Phellia gausapata
Invertebrates Sagartia elegans
Invertebrates Tubularia indivisa
Invertebrates Urticina felina
Species scientific name English common name Species group
Alaria esculenta Algae
Callophyllis laciniata Algae
Corallina officinalis Algae
Cryptopleura ramosa Algae
Delesseria sanguinea Algae
Dictyota dichotoma Algae
Kallymenia reniformis Algae
Laminaria hyperborea Algae
Laminaria ochroleuca Algae
Mastocarpus stellatus Algae
Palmaria palmata Algae
Phycodrys rubens Algae
Plocamium cartilagineum Algae
Alcyonium digitatum Invertebrates
Asterias rubens Invertebrates
Botryllus leachi Invertebrates
Cancer pagurus Invertebrates
Caryophyllia smithii Invertebrates
Corynactis viridis Invertebrates
Echinus esculentus Invertebrates
Electra pilosa Invertebrates
Halichondria panicea Invertebrates
Margarites helicinus Invertebrates
Membranipora membranacea Invertebrates
Nucella lapillus Dog whelk Invertebrates
Obelia geniculata Invertebrates
Pachymatisma johnstonia Invertebrates
Patella vulgata Invertebrates
Phellia gausapata Invertebrates
Sagartia elegans Invertebrates
Tubularia indivisa Invertebrates
Urticina felina Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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