Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA3.32 Kelp in variable salinity low energy Atlantic infralittoral rock

Kelp in variable salinity low energy Atlantic infralittoral rock

Quick facts

Red List habitat type code NEAA3.32
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 structurally complex habitat that develops in areas of very wave-sheltered infralittoral bedrock, boulders and cobbles subject to only weak tidal streams in the sublittoral fringe and infralittoral zone, with variable/reduced salinity typical for estuaries. The variabile salinity and increased turbidity have a signficiant effect on the biota, limiting species richness of seaweeds and the occurance to shallower parts of the infralittoral zone. The kelp canopy is characterised by Saccharina latissima only with accompanying foliose red seaweeds and coralline crusts. Laminaria hyperborea is generally missing due to the low salinity and weak tidal currents.  The associated biotopes may support dense stands of silted filamentous green seaweeds and red seaweeds,   depauperate coralline-encrusted rock with few foliose seaweeds but many grazing urchins and, in very shallow, heavily-silted situations, dense stands of Codium spp., together with silt-tolerant red seaweeds, the green seaweed Ulva spp. and often only a sparse covering of the kelp Saccharina latissima.

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. The depth limit of kelp and/or red seaweeds 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

There is a lack of information on the extent of this habitat and any trends in quantity or quality over the last 50 years. Future trends have not been predicted. For the purposes of Red List assessment it is therefore considered to be Data Deficient for both the EU 28 and EU 28+.
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
    • Disposal of household / Recreational facility waste
    • Disposal of industrial waste
    • Water discharges (with/without contaminants)
  • Pollution
    • Marine water pollution
    • Non-synthetic compound contamination
    • Synthetic compound contamination
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Landfill, land reclamation and drying out, general
    • Modification of hydrographic functioning, general
    • Modification of water flow (tidal & marine currents)
    • Wave exposure changes
    • Dykes, embankments, artificial beaches, general
    • Sea defense or coast protection works, tidal barrages
    • Dykes and flooding defense in inland water systems
  • Climate change
    • Flooding and rising precipitations
    • Water flow changes (limnic, tidal and oceanic)
    • Wave exposure changes

Habitat restoration potential

The dominating kelp species S. latissima is capable of rapid settling and fast growing. Therefore the dominating element can recover rapidly but establishment of a community containing the range of characteristic species associated with an undisturbed and mature community may take several years.

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 and management of this habitat should be through regulation of fishing methods which damage or disturb seabed communities. In addition, controls on activities that change the hydrological regime, such coastal development and hard coastal defence structures are also important. Furthermore, water quality improvement programmes to reduce the risk of contamination should also be considered. Lastly, measures to reduce climate change effects will benefit this habitat. This habitat is afforded protection within some Marine Protected Areas.

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

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 unknown unknown Unknown This habitat is widespread in estuaries and inlets however there is insufficient quantitative data to make an accurate estimate of EOO and AOO.
EU28+ unknown Unknown This habitat is widespread in estuaries and inlets however there is insufficient quantitative data to make an accurate estimate of EOO and AOO.
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 Laminaria hyperborea
Algae Lithothamnion glaciale
Algae Phycodrys rubens
Invertebrates Ascidiella scabra
Invertebrates Asterias rubens
Invertebrates Balanus crenatus
Invertebrates Buccinum undatum
Invertebrates Carcinus maenas
Invertebrates Ciona intestinalis
Invertebrates Corella parallelogramma
Invertebrates Echinus esculentus
Invertebrates Gibbula cineraria
Invertebrates Modiolus modiolus
Invertebrates Ophiothrix fragilis
Invertebrates Pagurus bernhardus
Invertebrates Pomatoceros triqueter
Invertebrates Psammechinus miliaris
Species scientific name English common name Species group
Laminaria hyperborea Algae
Lithothamnion glaciale Algae
Phycodrys rubens Algae
Ascidiella scabra Invertebrates
Asterias rubens Invertebrates
Balanus crenatus Invertebrates
Buccinum undatum Invertebrates
Carcinus maenas Invertebrates
Ciona intestinalis Invertebrates
Corella parallelogramma Invertebrates
Echinus esculentus Invertebrates
Gibbula cineraria Invertebrates
Modiolus modiolus Invertebrates
Ophiothrix fragilis Invertebrates
Pagurus bernhardus Invertebrates
Pomatoceros triqueter Invertebrates
Psammechinus miliaris 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