EUNIS habitat classification 2017 > M - Marine benthic habitats > MB1 - Infralittoral rock > MB12 - Atlantic infralittoral rock > MB121 - Kelp and seaweed communities on Atlantic infralittoral rock > MB1212 - Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed Atlantic infralittoral bedrock

Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed Atlantic infralittoral bedrock

Description (English)

This biotope has only been recorded from Rockall, where Alaria esculenta appears to replace Laminaria hyperborea as the dominant kelp forest species on the extremely wave-exposed steep and vertical rock, a zone that extends from 14 m down to 35 m. Beneath the A. esculenta canopy, the rock surface is covered by a dense turf of anthozoans such as Sagartia elegans, Phellia gausapata and Corynactis viridis, encrusting sponges and coralline algae. The gastropod Margarites helicinus can be found grazing on the kelp fronds, whereas the crab Cancer pagurus can be found among the kelp stipes. The bryozoan Tubularia indivisa also occur, but it does not form such a dense turf as in more shallow waters, while the ascidian Botryllus leachi is found encrusting the large brown seaweeds. Cryptopleura ramosa is the dominant red seaweed on horizontal surfaces. The kelp Laminaria digitata is reported to occur mixed with A. esculenta on the nearby Helen's reef.
Situation: Above the zone with MB1-212 (about 5 m to 13 m) A. esculenta still dominates, but it resembles more closely the typical sublittoral fringe A. esculenta biotope (unit MB1-2111), though it has a very dense turf of small hydroids and few foliose algae. Towards the lower part of this A. esculenta forest (30 m to 35 m), the density of A. esculenta is reduced and the rock surface is characterised by a dense turf of red algae (unit MB1-221).

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code MB1212
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Alaria esculenta
Algae Cryptopleura ramosa
Algae Laminaria digitata
Algae Laminaria hyperborea
Invertebrates Botryllus leachi
Invertebrates Cancer pagurus
Invertebrates Corynactis viridis
Invertebrates Margarites helicinus
Invertebrates Phellia gausapata
Invertebrates Sagartia elegans
Invertebrates Tubularia indivisa
Species scientific name English common name Species group
Alaria esculenta Algae
Cryptopleura ramosa Algae
Laminaria digitata Algae
Laminaria hyperborea Algae
Botryllus leachi Invertebrates
Cancer pagurus Invertebrates
Corynactis viridis Invertebrates
Margarites helicinus Invertebrates
Phellia gausapata Invertebrates
Sagartia elegans Invertebrates
Tubularia indivisa Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A3.112 Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A3.112 Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 200308 A3.112 Alaria esculenta forest with dense anemones and crustose sponges on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 200202 A3.112 Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
EUNIS Habitat Classification 199910 A3.112 Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
MNCR BioMar 97.06 (Britain & Ireland) EIR.KFaR.AlaAnSC Alaria esculenta forest with dense anemones and sponge crusts on extremely exposed infralittoral bedrock same
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