Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock

Quick facts

EUNIS habitat type code MB121A1
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Description (English)

Moderately exposed upper infralittoral bedrock and boulders characterised by a dense forest of Laminaria hyperborea with dense foliose red seaweeds beneath the canopy. These include Callophyllis laciniata, Plocamium cartilagineum, Cryptopleura ramosa and Delesseria sanguinea. Kelp stipes are usually covered in a rich mixture of red seaweeds of which Palmaria palmata, Phycodrys rubens and Membranoptera alata are often present. Small kelp plants can also be found on the larger kelp stipes. Kelp fronds may be covered with a hydroid growth of Obelia geniculata or the bryozoans Membranipora membranacea and Electra pilosa. The kelp holdfasts can be colonised by bryozoans Scrupocellaria spp. and/or crisiids and colonial ascidians such as Botryllus schlosseri. The rock surface between the kelp plants is generally covered by encrusting coralline algae, often with sponge crusts Halichondria panicea. Small vertical surfaces within the kelp forest generally lack kelp plants, instead being characterised by foliose red seaweeds such as Dictyota dichotoma, the anthozoans Alcyonium digitatum, Urticina felina and Caryophyllia smithii, the tube-building polychaete Pomatoceros triqueter and gastropods including Calliostoma zizyphinum and Gibbula cineraria. Many grazers are found in the kelp forest, the most commonly occurring being the gastropods Gibbula cineraria and Calliostoma zizyphinum and the echinoderm Echinus esculentus. Other echinoderms present include Asterias rubens and Antedon bifida which can be locally abundant, particularly in the north-west.
Situation: This biotope occurs over a wide geographic area and is generally found below the sublittoral fringe Laminaria digitata zone (unit MB1-23A1) and above the L. hyperborea park (unit MB1-21A2). In the north, Shetland in particular, unit MB1-232 can occur in the lower infralittoral; where grazing influence is present the abundance of red seaweeds may be much reduced (unit MB1-21A4). In turbid water kelp park is often absent and dense foliose seaweed cover may occur instead (unit MB1-21B). In areas affected by scour, such as the rock-sediment interface at the base of bedrock slopes, a mixed kelp canopy can develop below the kelp forest (unit MB1-235).
Temporal variation: The under-storey of foliose and filamentous seaweeds will diminish towards the autumn and regrow in the spring. Otherwise this biotope is not known to vary markedly over time. Certain areas are prone to urchin grazing and this can substantially alter the community structure of the biotope, such that any site subject to intensive urchin grazing should be recorded as unit MB1-21A3.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Callophyllis laciniata
Algae Cryptopleura ramosa
Algae Delesseria sanguinea
Algae Dictyota dichotoma
Algae Laminaria digitata
Algae Laminaria hyperborea
Algae Membranoptera alata
Algae Palmaria palmata
Algae Phycodrys rubens
Algae Plocamium cartilagineum
Invertebrates Antedon bifida
Invertebrates Asterias rubens
Invertebrates Calliostoma zizyphinum
Invertebrates Caryophyllia smithii
Invertebrates Echinus esculentus
Invertebrates Electra pilosa
Invertebrates Gibbula cineraria
Invertebrates Halichondria panicea
Invertebrates Membranipora membranacea
Invertebrates Obelia geniculata
Invertebrates Urticina felina
Species scientific name English common name Species group
Callophyllis laciniata Algae
Cryptopleura ramosa Algae
Delesseria sanguinea Algae
Dictyota dichotoma Algae
Laminaria digitata Algae
Laminaria hyperborea Algae
Membranoptera alata Algae
Palmaria palmata Algae
Phycodrys rubens Algae
Plocamium cartilagineum Algae
Antedon bifida Invertebrates
Asterias rubens Invertebrates
Calliostoma zizyphinum Invertebrates
Caryophyllia smithii Invertebrates
Echinus esculentus Invertebrates
Electra pilosa Invertebrates
Gibbula cineraria Invertebrates
Halichondria panicea Invertebrates
Membranipora membranacea Invertebrates
Obelia geniculata Invertebrates
Urticina felina Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A3.2141 Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A3.2141 Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
EUNIS Habitat Classification 200308 A3.2121 Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
EUNIS Habitat Classification 200202 A3.2121 Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
EUNIS Habitat Classification 199910 A3.2121 Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) MIR.KR.Lhyp.Ft Laminaria hyperborea forest and foliose red seaweeds on moderately exposed upper infralittoral rock same
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