Skip to Content

Marine Habitat Classification


Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Laminaria digitata on moderately exposed sublittoral fringe bedrock


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Exposed, Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Bedrock; boulders
Zone Sublittoral fringe
Depth Band 0-5 m, Lower shore
Other Features

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.MIR.KR.Ldig.Ldig <I>Laminaria digitata</I> on moderately exposed sublittoral fringe bedrock

  • 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

Exposed to sheltered sublittoral fringe bedrock dominated by a dense canopy of Laminaria digitata, often with a wide range of filamentous and foliose red seaweeds beneath. The most frequently occurring red seaweeds are Palmaria palmata, Corallina officinalis, Mastocarpus stellatus, Chondrus crispus, Lomentaria articulata and Membranoptera alata. Generally the rocky substratum is covered by encrusting coralline algae, on which occasional limpets Patella vulgata and topshells Gibbula cineraria graze. A wide variety of fauna occurs, some of the most commonly occurring species being the sponge Halichondria panicea and the tube-building polychaete Pomatoceros triqueter. Kelp holdfasts provide a refuge for a varied assemblage of species such as sponges and the limpet Helcion pellucidum, while encrusting bryozoans such as Electra pilosa more often are found on the fronds of foliose red seaweeds. Solitary ascidians may be locally abundant where overhanging or vertical rock occurs, while the hydroid Dynamena pumila can be abundant on Fucus serratus and Laminaria sp. fronds. On exposed, wave-surged shores, the robust red seaweeds M. stellatus, C. crispus and C. officinalis can form a dense turf beneath the kelp along with the occasional green seaweed Ulva lactuca. Similarly on such shores the mussel Mytilus edulis can occur in extremely dense aggregations on the rock, beneath the kelp canopy.

Situation

This biotope is usually found on the extreme low shore below the Fucus serratus zone (Fser) and above the truly sublittoral Laminaria hyperborea zone (Lhyp).

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
Halichondria panicea 3 Occasional 41-60 %
Dynamena pumila 1 Occasional 21-40 %
Pomatoceros triqueter 1 Occasional 41-60 %
Gibbula cineraria 2 Occasional 41-60 %
Patella vulgata 2 Occasional 21-40 %
Helcion pellucidum 1 Occasional 21-40 %
Mytilus edulis 1 Occasional 21-40 %
Electra pilosa 3 Occasional 41-60 %
Palmaria palmata 5 Frequent 61-80 %
Corallinaceae 13 Abundant 61-80 %
Corallina officinalis 4 Occasional 41-60 %
Chondrus crispus 4 Frequent 61-80 %
Mastocarpus stellatus 4 Frequent 41-60 %
Lomentaria articulata 1 Occasional 21-40 %
Membranoptera alata 2 Occasional 41-60 %
Laminaria digitata 29 Abundant 81-100 %
Fucus serratus 3 Occasional 41-60 %
Ulva lactuca 1 Occasional 21-40 %

Similar biotopes

IR.HIR.KFaR.Ala.Ldig
Alaria esculenta is generally at least Common in this biotope and/or of similar abundance to L. digitata, with dense mussels and barnacles overgrowing coralline-encrusted rock.

IR.MIR.KR.Ldig.Bo
L. digitata on moderately exposed boulder shores and occasionally on exposed or sheltered shores. Other canopy-forming kelps such as A. esculenta and Laminaria saccharina are not present in this biotope.

IR.MIR.KR.Ldig.Pid
L. digitata and rock-boring animals such as piddocks (Barnea candida, Pholas dactylus and Petricola pholadiformis), the bivalve Hiatella arctica and worms Polydora spp. on soft littoral fringe rock.

IR.MIR.KR.Ldig.Ldig
L. saccharina and L. digitata generally occur in equal abundance on silted, sheltered rock. Kelps often 'cape-form'. Fewer faunal species and fewer red seaweeds is present, but Chorda filum often present.

Biotope history

Classification Habitat code
6.95 LRK.LDIG.LDIG

Photos

IR.MIR.KR.Ldig.Ldig Laminaria digitata on moderately exposed sublittoral fringe bedrock, Wembury. Keith Hiscock © JNCC
IR.MIR.KR.Ldig.Ldig Laminaria digitata on moderately exposed sublittoral fringe bedrock, Wembury. Keith Hiscock © JNCC
IR.MIR.KR.Ldig.Ldig Laminaria digitata on moderately exposed sublittoral fringe bedrock, Auliston Point, Loch Sunart. Dale Rostron © JNCC
IR.MIR.KR.Ldig.Ldig Laminaria digitata on moderately exposed sublittoral fringe bedrock, Auliston Point, Loch Sunart. Dale Rostron © JNCC

Back to top