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Marine Habitat Classification


Description of biotope or habitat type

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   Sabellaria alveolata reefs on sand-abraded eulittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed
Tidal streams
Substratum Cobbles; boulders; pebbles; sand
Zone Eulittoral - lower, Eulittoral - mid
Depth Band Lower shore, Mid shore
Other Features Sand-abraded

Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.

Distribution of habitat LS.LBR.Sab.Salv <I>Sabellaria alveolata</I> reefs on sand-abraded eulittoral rock

  • Records used to define the biotope (core records)
  • Other records assigned to this biotope, marked as 'certain'
  • Other records assigned to this biotope, marked as 'uncertain'

Point data based on records in the UK Marine Recorder Snapshot.

Description

Exposed to moderately exposed bedrock and boulders in the eastern basin of the Irish Sea (and as far south as Cornwall) characterised by reefs of the polychaete Sabellaria alveolata. The sand based tubes formed by S. alveolata form large reef-like hummocks, which serve to stabilise the boulders and cobbles. Other species in this biotope include the barnacles Semibalanus balanoides and Elminius modestus and the limpet Patella vulgata, the winkle Littorina littorea, the mussel Mytilus edulis and the whelk Nucella lapillus. The anemone Actinia equina and the crab Carcinus maenas can be present in cracks and crevices on the reef. Low abundance of seaweeds tend to occur in areas of eroded reef. The seaweed diversity can be high and may include the foliose red seaweeds Palmaria palmata, Mastocarpus stellatus, Osmundea pinnatifida, Chondrus crispus and some filamentous species e.g. Polysiphonia spp. and Ceramium spp. Coralline crusts can occur in patches. Wracks such as Fucus vesiculosus, Fucus serratus and the brown seaweed Cladostephus spongiosus may occur along with the ephemeral green seaweeds Enteromorpha intestinalis and Ulva lactuca. On exposed surf beaches in the south-west S. alveolata forms a crust on the rocks, rather than the classic honeycomb reef form, and may be accompanied by the barnacle Balanus perforatus (typically common to abundant). On wave-exposed shores in Ireland, the wrack Himanthalia elongata can also occur.

Situation

Above Salv are biotopes dominated either by ephemeral seaweeds, such as Enteromorpha spp. and Porphyra spp. or the perennial wrack Fucus vesiculosus on mixed substrata (FvesB; Fves.X; EphX; EntPor). Rockpool biotopes dominated by the red seaweed Corallina officinalis (Cor), by wracks such as Fucus spp. or by kelp such as Laminaria spp. (FK) can usually be found above this biotope. Beneath this biotope is a community consisting of mixed scour-tolerant like the kelp Laminaria digitata and opportunistic foliose red seaweeds such as Polyides rotundus and Ahnfeltia plicata (Ldig.Ldig; XKScrR; EphR; PolAhn). In adjacent sediment areas Lanice conchilega may dominante (Lan).

Temporal variation

These reefs may be susceptible to storm damage in the winter, although they can regenerate remarkably quickly in a season as long as some adults are left as they facilitate the larval settlement. S. alveolata is tolerant to burial under sand for several weeks. Changes in desiccation over a period of time can cause part of the population to die.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Actinia equina 2 Occasional 41-60 %
Sabellaria alveolata 24 Common 81-100 %
Lanice conchilega 1 Occasional 21-40 %
Elminius modestus 2 Occasional 21-40 %
Semibalanus balanoides 8 Frequent 61-80 %
Carcinus maenas 1 Occasional 21-40 %
Gibbula cineraria 1 Rare 21-40 %
Patella vulgata 5 Occasional 61-80 %
Littorina littorea 6 Frequent 61-80 %
Nucella lapillus 7 Frequent 61-80 %
Mytilus edulis 3 Occasional 41-60 %
Palmaria palmata 2 Occasional 41-60 %
Corallinaceae 3 Frequent 41-60 %
Corallina officinalis 2 Occasional 41-60 %
Chondrus crispus 2 Occasional 41-60 %
Mastocarpus stellatus 2 Occasional 41-60 %
Ceramium nodulosum 2 Occasional 41-60 %
Osmundea pinnatifida 2 Frequent 41-60 %
Polysiphonia 2 Occasional 21-40 %
Cladostephus spongiosus 2 Occasional 41-60 %
Fucus serratus 5 Frequent 61-80 %
Fucus vesiculosus 2 Occasional 21-40 %
Enteromorpha intestinalis 1 Occasional 21-40 %
Ulva lactuca 4 Occasional 61-80 %

Similar biotopes

IR.MIR.KR.Lhyp.Sab
Occurs in the upper infralittoral zone. Kelp such as Laminaria spp. are present.

Biotope history

Classification Habitat code
6.95 LMXD.SAB
96.7 MLR.Sab

Photos

LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Unspecified location. Rohan Holt © JNCC
LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Unspecified location. Rohan Holt © JNCC
LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Tarn Bay. Roger Covey © JNCC
LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Tarn Bay. Roger Covey © JNCC
LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Unspecified location. Rohan Holt © JNCC
LR.MLR.SAB.Salv Sabellaria alveolata reefs on sand-abraded eulittoral rock, Unspecified location. Rohan Holt © JNCC

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