Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock

English name: Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock

Quick facts

EUNIS habitat type code A3.1112
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Description (English)

Exposed sublittoral fringe bedrock characterised by a mixture of the kelps Laminaria digitata and Alaria esculenta with an understorey of red seaweeds including Palmaria palmata and Corallina officinalis with encrusting coralline algal on the rock surface. Anthozoans such as Halichondria panicea, the mussel Mytilus edulis and the barnacle Semibalanus balanoides can be found attached in cracks and crevices. The limpets Patella vulgata or on southern shores Patella ulyssiponensis can be found in their characteristic "scars" grazing the biofilm/algal crusts on the rock surface, while the limpet Helcion pellucidum is restricted to grazing the kelp fronds. Colonies of the bryozoan Electra pilosa can cover the red seaweeds Mastocarpus stellatus and Chondrus crispus or the rock surface.
Situation: This unit represents an intermediate on the wave exposure gradient, with pure stands of A. esculenta (unit A3.1111) being found on more exposed shores and pure L. digitata (unit A3.1112) on more sheltered shores. This biotope usually occurs immediately above a sublittoral Laminaria hyperborea forest (units A3.115 or A3.214), although a narrow band of L. digitata (A3.1112) may occur between these two zones, particularly on less exposed shores. In southwest England a zone of mixed kelp forest L. hyperborea and Laminaria ochroleuca may occur below the A. esculenta (A3.1153). A number of different biotopes can occur above A3.1112; most commonly these are the mussel-barnacle zone (A1.111), Himanthalia elongata (A1.123), a red algal turf or a Fucus serratus-red algal mosaic (A1.2141) on the less exposed shores. This biotope also occurs on steep and vertical shores of moderately exposed coasts where a localised increase in wave action restricts the growth of L. digitata. As a result of this increased wave action the L. digitata plants are usually small and often show signs of damage.
Temporal variation: There may be seasonal changes in the amount of ephemeral seaweeds due to disturbance caused by winter storms.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Alaria esculenta
Algae Chondrus crispus
Algae Corallina officinalis
Invertebrates Electra pilosa
Algae Fucus serratus
Invertebrates Halichondria panicea
Algae Himanthalia elongata
Algae Laminaria digitata
Algae Laminaria hyperborea
Algae Laminaria ochroleuca
Algae Mastocarpus stellatus
Invertebrates Mytilus edulis
Algae Palmaria palmata
Invertebrates Patella ulyssiponensis
Invertebrates Patella vulgata
Invertebrates Semibalanus balanoides
Species scientific name English common name Species group
Alaria esculenta Algae
Chondrus crispus Algae
Corallina officinalis Algae
Electra pilosa Invertebrates
Fucus serratus Algae
Halichondria panicea Invertebrates
Himanthalia elongata Algae
Laminaria digitata Algae
Laminaria hyperborea Algae
Laminaria ochroleuca Algae
Mastocarpus stellatus Algae
Mytilus edulis Invertebrates
Palmaria palmata Algae
Patella ulyssiponensis Invertebrates
Patella vulgata Invertebrates
Semibalanus balanoides Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.HIR.KFaR.Ala.Ldig <I>Alaria esculenta</I> and <I>Laminaria digitata</I> on exposed sublittoral fringe bedrock source
CORINE Land Cover 5.2.3. Sea and ocean n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A3.1112 Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock same
EUNIS Habitat Classification 200308 A3.1112 Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock same
EUNIS Habitat Classification 200202 A3.1112 Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock same
EUNIS Habitat Classification 199910 A3.1112 Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock same
MNCR BioMar 97.06 (Britain & Ireland) EIR.KFaR.Ala.Ldig Alaria esculenta and Laminaria digitata on exposed sublittoral fringe bedrock same
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