EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A1 - Littoral rock and other hard substrata > A1.1 - High energy littoral rock > A1.12 - Robust fucoid and/or red seaweed communities > A1.121 - Fucus distichus and Fucus spiralis f. nana on extremely exposed upper eulittoral rock

Fucus distichus and Fucus spiralis f. nana on extremely exposed upper eulittoral rock

English name: Fucus distichus and Fucus spiralis f. nana on extremely exposed upper eulittoral rock

Quick facts

EUNIS habitat type code A1.121

Description (English)

Extremely exposed gently or steeply sloping upper shore bedrock which supports a mixture of the wracks Fucus distichus and Fucus spiralis f. nana, the latter often at the top of the zone. On some sites F. distichus dominates and F. spiralis is not present. Other seaweeds normally found on exposed coasts are common in this biotope. These include ephemeral species such as the foliose red Porphyra umbilicalis and the green Enteromorpha spp. The winkles Melarhaphe neritoides and Littorina saxatilis can be found grazing on the bedrock or on the fucoids, while red crusts of Hildenbrandia rubra and the mussel Mytilus edulis are restricted to moist cracks and crevices. A sparse covering of the black lichens Verrucaria maura and Verrucaria mucosa can be found in the upper part of this biotope competing for space with barnacle Semibalanus balanoides and the limpet Patella vulgata. This biotope is very rare and restricted to the far north and west coasts.
Situation: This mixed band of F. distichus and F. spiralis f. nana is generally found between the Verrucaria maura and Porphyra spp. zone (B3.1131 or B3.1132) above, and the M. edulis and barnacle zone below (A1.111). It may also occur above a red algal zone consisting of Mastocarpus stellatus as recorded on Barra (Scotland).
Temporal variation: Due to the occurrence of this biotope on very exposed coasts a certain amount of fluctuation between this biotope and unit B3.1131 from year to year is to be expected. More information is required to validate this hypothesis. There can be seasonal fluctuations in the density of ephemeral green algae.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Fucus distichus
Algae Fucus spiralis
Algae Hildenbrandia rubra
Invertebrates Littorina saxatilis
Algae Mastocarpus stellatus
Invertebrates Melarhaphe neritoides
Invertebrates Mytilus edulis
Invertebrates Patella vulgata
Algae Porphyra umbilicalis
Invertebrates Semibalanus balanoides
Species scientific name English common name Species group
Fucus distichus Algae
Fucus spiralis Algae
Hildenbrandia rubra Algae
Littorina saxatilis Invertebrates
Mastocarpus stellatus Algae
Melarhaphe neritoides Invertebrates
Mytilus edulis Invertebrates
Patella vulgata Invertebrates
Porphyra umbilicalis Algae
Semibalanus balanoides Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 LR.HLR.FR.Fdis <I>Fucus distichus</I> and <I>Fucus spiralis</I> f. <I>nana</I> on extremely exposed upper shore rock source
CORINE Land Cover 4.2.3. Intertidal flats n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A1.121 Fucus distichus and Fucus spiralis f. nana on extremely exposed upper eulittoral rock same
EUNIS Habitat Classification 200308 A1.121 Fucus distichus and Fucus spiralis f. nana on extremely exposed upper eulittoral rock same
EUNIS Habitat Classification 200202 A1.121 Fucus distichus subsp. anceps and Fucus spiralis f. nana on extremely exposed upper eulittoral rock same
EUNIS Habitat Classification 199910 A1.121 Fucus distichus subsp. anceps and Fucus spiralis f. nana on extremely exposed upper eulittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) ELR.FR.Fdis Fucus distichus subsp. anceps and Fucus spiralis f. nana on extremely exposed upper eulittoral rock same
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