Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA5.52 Kelp and seaweed communities on Atlantic infralittoral mixed sediment

Kelp and seaweed communities on Atlantic infralittoral mixed sediment

Quick facts

Red List habitat type code NEAA5.52
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

Shallow sublittoral mixed sediments consisting of hard substrate components (cobbles, pebbles, gravel and shells) in various densities which support seaweed communities, typically including the kelp Saccharina latissima the bootlace weed Chorda filum and various red and brown seaweeds, particularly filamentous types. The environmental conditions also dictate the typical seaweed communities present. In areas where winter storms are common, seaweed cover will be more ephemeral and fragmented, due to high mortality rates from damage and detachment; whilst in more sheltered areas, long term attachment to smaller cobbles/pebbles is possible. Loose mats may be present in the most sheltered environments. The strength of tidal flow and type of substrate also influence the community type.

A diverse array of animals is associated with these kelps and seaweeds, including burrowing polychaete worms and bivalves, scavenging hermit crabs, crabs, starfish, fish and grazing top shells. Kelps and seaweeds growing on sediment greatly increase the primary production of an area and create a more diverse habitat. Gastropods, amphipods, sea urchins and fish graze the seaweeds; starfish, urchins, hermit crabs and crabs are scavengers; crabs and fish are opportunistic predators; and a mixed infauna of deposit feeders and suspension feeders develops, depending on sediment type. Various biotopes have been described associated with this habitat characteristised by Saccharina.latissima, Chorda.filum and red seaweeds on sheltered muddy sediments as well as mats of  Trailliella on muddy gravel  and  loose-lying mats of Phyllophora crispa on muddy sediment.

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

Survey information confirms that this habitat has a widespread distribution in the North East Atlantic. It has been studied in detail in some localities however there is insufficient information to determine whether there have been any historical, recent and trends in quantity or quality.
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 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
    • Marine and Freshwater Aquaculture
    • Fishing and harvesting aquatic resources
    • Professional active fishing
    • Benthic or demersal trawling
    • Benthic dredging
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
    • Marine water pollution
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Removal of sediments (mud...)

Habitat restoration potential

Removal of the substratum will remove most of the key species of this feature, although if suitable substratum remains, recovery is likely to be rapid as most of the epibiota species are known to be rapid colonizers and fast growing. Sediment infauna are probably slower to re-colonise and develop into a stable community. Some species such as Cerianthus lloydii may be very slow to re-establish after disturbance. Overall, because of the dominance of rapid settling and fast growing species, such as S.latissima and C.filum, some of the elements 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

This habitat is afforded some protection within some Marine Protected Areas. Beneficial management measures include the control of bottom-contact fishing activity, the regulation of dredging, aquaculture and the construction of hard coastal defence structures. Additionally, water quality improvement programmes to reduce the risk of toxic contamination or nutrient inputs leading to eutrophication should also be considered.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
  • Measures related to spatial planning
    • Establish protected areas/sites
  • Measures related to urban areas, industry, energy and transport
    • Urban and industrial waste management

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 590,514 172 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+ >172 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 Chorda filum
Algae Phycodrys rubens
Algae Phyllophora crispa
Invertebrates Ampelisca brevicornis
Invertebrates Asterias rubens
Invertebrates Capitella capitata
Invertebrates Heterochaeta costata
Invertebrates Liocarcinus depurator
Invertebrates Mediomastus fragilis
Invertebrates Mysella bidentata
Invertebrates Pagurus bernhardus
Invertebrates Tubificoides benedii
Species scientific name English common name Species group
Chorda filum Algae
Phycodrys rubens Algae
Phyllophora crispa Algae
Ampelisca brevicornis Invertebrates
Asterias rubens Invertebrates
Capitella capitata Invertebrates
Heterochaeta costata Invertebrates
Liocarcinus depurator Invertebrates
Mediomastus fragilis Invertebrates
Mysella bidentata Invertebrates
Pagurus bernhardus Invertebrates
Tubificoides benedii Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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