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Marine Habitat Classification


Description of biotope or habitat type

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   Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Very exposed, Exposed, Moderately exposed
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock
Zone Infralittoral, Sublittoral fringe
Depth Band 0-5 m, 5-10 m, 10-20 m
Other Features Wave-surged gullies or caves;

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 IR.FIR.SG.DenCcor <I>Dendrodoa grossularia</I> and <I>Clathrina coriacea</I> on wave-surged vertical infralittoral 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.

Description

Vertical or overhanging infralittoral rock subject to considerable wave-surge, especially in the middle or back of caves but also in gullies and tunnels, and dominated by dense sheets of the ascidian Dendrodoa grossularia, together with variable quantities of the sponge Clathrina coriacea. At some sites D. grossularia forms continuous sheets, with few other species present. Other sponges such as Esperiopsis fucorum, Pachymatisma johnstonia, Leucosolenia botryoides, Scypha ciliata and Halichondria panicea regularly occur in this biotope, though generally at low abundance. Other ascidians, especially Polyclinum aurantium, Diplosoma spp. and other didemnids may also occur, though only P. aurantium is ever as abundant as D. grossularia. Being characteristically found in the middle or towards the backs of the caves mean that there is generally insufficient light to support any foliose seaweeds, although encrusting coralline algae are not uncommon. More scoured areas may also contain the anemone Urticina felina, whilst Sagartia elegans is often present in low numbers. Mobile fauna are often limited to the starfish Asterias rubens and Henricia spp., the brittlestar Ophiopholis aculeata and crabs Cancer pagurus and Necora puber. The barnacle Balanus crenatus can occur, usually in low densities.

Situation

Where this biotope develops in a cave or tunnel it can occur anywhere from the entrance to the rear of the system. Typically, it will give way to sponge crust or barnacle and encrusting tubeworm communities at the rear of the cave, where surge forces are amplified (CrSp or CC.BalPom). The vertical rock below the DenCla zone, abutting the cave/gully floor, is likely to be severely scoured, colonised by the robust CC.BalPom biotope. The cave or gully floor is generally scoured clean by boulders and/or cobbles (CC.Mo). The cave or gully entrance has more available light for algal growth so dense foliose seaweeds usually dominate the rock walls at the entrance, abutting the D. grossularia - C. coriacea zone further into the cave (FoSwCC). This dense seaweed growth may also extend to the upward-facing surfaces of boulders around the entrance. Where DenCla occurs in a gully situation, the rock tends to be colonised by dense Alaria esculenta in the sublittoral fringe (Ala) or by Laminaria hyperborea forest in the shallow infralittoral (LhypR.Ft).

Temporal variation

Unknown.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Clathrina coriacea 16 Common 81-100 %
Leucosolenia complicata 2 Frequent 21-40 %
Scypha ciliata 1 Occasional 21-40 %
Grantia compressa 1 Occasional 21-40 %
Pachymatisma johnstonia 3 Frequent 41-60 %
Halichondria panicea 4 Frequent 41-60 %
Porifera indet crusts 1 Occasional 21-40 %
Urticina felina 2 Occasional 41-60 %
Sagartia elegans 2 Occasional 21-40 %
Spirorbidae 1 Frequent 21-40 %
Balanus crenatus 3 Frequent 61-80 %
Cancer pagurus 4 Occasional 41-60 %
Necora puber 1 Rare 21-40 %
Henricia 2 Occasional 21-40 %
Asterias rubens 2 Occasional 21-40 %
Ophiopholis aculeata 2 Occasional 21-40 %
Polyclinum aurantium 1 Occasional 21-40 %
Didemnidae 1 Occasional 21-40 %
Dendrodoa grossularia 32 Abundant 81-100 %
Botryllus schlosseri 1 Occasional 21-40 %
Corallinaceae 1 Occasional 21-40 %

Similar biotopes

Not applicable or unknown.

Biotope history

Classification Habitat code
97.06 EIR.SCAs.DenCla

Photos

IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Scolpaig, North Uist. Francis Dipper © JNCC
IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Scolpaig, North Uist. Francis Dipper © JNCC
IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Deer Sound, Orkney. Eleanor Murray © JNCC
IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Deer Sound, Orkney. Eleanor Murray © JNCC
IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Islay. Keith Hiscock © JNCC
IR.FIR.SG.CrSpAs.DenCla Dendrodoa grossularia and Clathrina coriacea on wave-surged vertical infralittoral rock, Islay. Keith Hiscock © JNCC

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