Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA5.61 Polychaete worm reefs on Atlantic sublittoral sediment

Polychaete worm reefs on Atlantic sublittoral sediment

Quick facts

Red List habitat type code NEAA5.61
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

Sublittoral reefs of polychaete worms in mixed sediments are found in a variety of hydrographic conditions. Such habitats may range from extensive structures of tightly packed tubes to loose agglomerations of tubes. Patchiness can be a feature of this habitat with the reef structures interspersed with areas of sediment.They often play an important role in the structural composition or stability of the seabed and provide a wide range of niches for other species to inhabit. Consequently polychaete worm reefs often support a diverse flora and fauna. Three biotopes associated with this habitat have been described with different species of polychaete dominating: Sabellaria spinulosa on stable circalittoral mixed sediment,  Sabellaria alveolata on variable salinity sublittoral mixed sediment and Serpula vermicularis reefs on very sheltered circalittoral muddy sand.

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 overall quality and continued occurrence of this habitat is, largely dependent on the presence of tubeworms which creates the biogenic structural complexity on which the characteristic associated communities depend. The density and the maintenance of a viable population of this species is a key indicator of habitat quality, together with the visual evidence of presence or absence of physical damage.

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 determining its extent and any trends in quantity and quality is problematic not only because patchiness is a feature of this habitat, with the reef structures interspersed with areas of sediment, but also because of the apparently ephemeral nature of the most abundant and widespread polychaete worm reefs (i.e. those created by S.spinulosa).
While detailed, repeat assessments of S. spinulosa reef structures are rare S.spinulosa reefs are known to have been seriously degraded and reduced in the German Waddensea (by around 85%) over the last century. Over the last decade a further decline of around 33% is considered to have occurred. In the UK there are some localities where reefs are no longer present. Records indicate increases from the 1980's to the 2000's in the western North Sea with new reefs located off the southern North Sea in 2009. Trends in quality of subittoral S.alveolata reefs are also largely unknown whilst those of S.vermicularis appear to have shown substantial degradation. As the most abundant and extensive examples of this habitat are the reefs of S.spinulosa, the overall current trend in quantity and quality of this habitat is unknown.
Historical losses are known to have been substantial however it is not possible to determine whether these losses exceeded the threshold for Red Listing (loss of more than 40% of the extent of this habitat since 1750).
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 given the lack of information on its trends in quantity and quality and the fact that its overall distribution is unknown.
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

  • Mining, extraction of materials and energy production
    • Mining and quarrying
    • Sand and gravel extraction
    • Exploration and extraction of oil or gas
    • Renewable abiotic energy use
  • Transportation and service corridors
    • Utility and service lines
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
    • Professional active fishing
    • Benthic or demersal trawling
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Removal of sediments (mud...)
    • Extraction of sea-floor and subsoil minerals (e.g. sand, gravel, rock, oil, gas)

Habitat restoration potential

Given the apparent the ephemeral nature of the most abundant and widespread polychaete worm reefs (i.e. those created by S.spinulosa) reef structures which have some capacity to regenerate after natural collapse events through the settlement and growth of new individuals the timescale is likely to be short.

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

Protected areas and management measures include the regulation of fisheries and, waste water treatment (to reduce the risk of eutrophication) and reduction in suspended sediments can benefit this habitat. Proactive protection may be achieved through Environmental Impact studies prior to offshore developments or activities such as sand and gravel extraction that can damage this habitat type.

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
    • 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
Kattegat
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 174,236 52 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+ >52 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.
Invertebrates Abra alba
Invertebrates Ascidia mentula
Invertebrates Asterias rubens
Invertebrates Buccinum undatum
Invertebrates Eulalia tripunctata
Invertebrates Eumida sanguinea
Invertebrates Flustra foliacea
Invertebrates Gibbula cineraria
Invertebrates Harmothoe impar
Invertebrates Lanice conchilega
Invertebrates Mediomastus fragilis
Invertebrates Nemertesia antennina
Invertebrates Ophiothrix fragilis
Invertebrates Pagurus bernhardus
Invertebrates Psammechinus miliaris
Invertebrates Sabellaria alveolata
Invertebrates Sabellaria spinulosa
Invertebrates Scoloplos armiger
Invertebrates Serpula vermicularis
Species scientific name English common name Species group
Abra alba Invertebrates
Ascidia mentula Invertebrates
Asterias rubens Invertebrates
Buccinum undatum Invertebrates
Eulalia tripunctata Invertebrates
Eumida sanguinea Invertebrates
Flustra foliacea Invertebrates
Gibbula cineraria Invertebrates
Harmothoe impar Invertebrates
Lanice conchilega Invertebrates
Mediomastus fragilis Invertebrates
Nemertesia antennina Invertebrates
Ophiothrix fragilis Invertebrates
Pagurus bernhardus Invertebrates
Psammechinus miliaris Invertebrates
Sabellaria alveolata Invertebrates
Sabellaria spinulosa Invertebrates
Scoloplos armiger Invertebrates
Serpula vermicularis Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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