Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA4.22 Sabellaria reefs on moderate energy Atlantic circalittoral rock

Sabellaria reefs on moderate energy Atlantic circalittoral rock

Quick facts

Red List habitat type code NEAA4.22
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)


This habitat occurs on moderately wave-exposed, circalittoral bedrock, boulders and cobbles subject to moderately strong tidal streams and is characterised by dense crusts on the upper faces of the hard surfaces formed by the sandy tubes of the polychaete worm Sabellaria spinulosa. In some cases the S.spinulosa may completely cover the rock, binding gravel and pebbles together. A diverse fauna may be found attached to and sometimes obscuring the crust, often reflecting the character of surrounding biotopes. There is usually no significant raised reef area.

Indicators of quality:

The condition of S. spinulosa reefs can be judged in different ways. For instance: the areal extent of the reef, its spatial patchiness, temporal stability, or number of associated species. Categorisation of condition may also consider a combination of these parameters. At present there is no consensus of approach or accepted yardstick against which to compare condition of individual reefs. Further to this, evidence suggests that S. spinulosa reefs may repeatedly develop and decline in a regular succession, through resettlement and demise of successive generations. An apparent deterioration in condition may therefore be natural and not necessarily reflective of an anthropogenic impact. The apparently ephemeral nature of S. spinulosa reefs is such that the condition of S. spinulosa reef habitat should be considered at a wider scale than individual reefs.

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

Threat status

Synthesis of Red List assessment

The difficulty in detecting and categorising S. spinulosa reef structures, their spatially patchy distribution and their temporal instability all add to uncertainty about the current distribution, quantity and quality of this habitat in the North East Atlantic. The current area of reef has been estimated in some locations but not necessarily distinguishing between the occurrence of S.spinulosa on predominantly soft sediment and where it is associated with pebbles, cobbles, boulders and rock. An added complication is that trends and longevity can be related to the stability of the substratum. Longer lasting reefs might be limited to more stable substrata while thin crust like forms are probably annual or transitent features and may break up during winter storms.
There is insufficient information to provide an overall estimate of the extent of this habitat and any historical, recent and possible future trends in quantity and quality. For the purposes of Red List assessment this habitat is therefore considered to be Data Deficient for both the EU 28 and EU 28+.
Red List Category Red List Criteria
Data Deficient
Red List Category Red List Criteria
Data Deficient

Confidence in the assessment

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
  • 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
    • Modification of hydrographic functioning, general

Habitat restoration potential

There is limited information on reef longevity, stability and recovery however S.spinulosa is known to be a fast growing species which can recolonise quickly. Recruitment rates are high and recovery could be quite rapid as this species is often one of the first to settle on newly exposed surfaces. Existing tubes strongly stimulate settlement.

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

Management of marine activities and, in particular, certain fishing practices will be important in preventing further threat and decline of this habitat. Known reef areas could be protected through site safeguard. It should also be noted that as the larvae are strongly stimulated to metamorphose and settle on the tubes of both living and dead worms, conservation management could usefully be directed towards the protection of both living and dead reefs. Zoning to ensure that aggregate extraction does not take place on reef habitats is another management option and will depend on sufficient knowledge of the distribution of reef habitat.
Management proposals need to reflect the dynamic nature of reefs which can colonise, evolve and degrade rapidly. Research into the stability, rate of establishment, and recovery of damaged reefs will also be important as will better knowledge of the environmental conditions under which they do so and natural variation in extent, density and population structure of S.spinulosa reefs.

List of conservation and management needs

  • Measures related to spatial planning
    • Other marine-related measures
    • Establish protected areas/sites
  • Measures related to hunting, taking and fishing and species management
    • Regulation/Management of fishery in marine and brackish systems
  • Measures related to special resouce use
    • Regulating/Managing exploitation of natural resources on sea


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

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 There is insufficient information for accurate calculation of EOO and AOO.
EU28+ Unknown Unknown There is insufficient information for accurate calculation 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

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

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