EUNIS habitat classification 2017 > M - Marine benthic habitats > MA1 - Littoral rock > MA12 - Atlantic littoral rock > MA123 - Seaweed communities on full salinity Atlantic littoral rock > MA1238 - Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock

Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock

Quick facts

EUNIS habitat type code MA1238
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Description (English)

Very sheltered to extremely sheltered areas of mid eulittoral rock that are subject to strong to moderate tidal streams, such as the narrows in sea lochs, and characterised by the wrack Ascophyllum nodosum. The wracks Fucus vesiculosus and Fucus serratus are occasionally present. The increased water movement encourages a rich associated fauna including several filter-feeding groups. These include the sponges Leucosolenia spp., Grantia compressa, Halichondria panicea and Hymeniacidon perleve which frequently occur on steep and overhanging faces of boulders and bedrock. It also includes the sea squirts Dendrodoa grossularia and Ascidiella scabra, which occur on steep surfaces and beneath boulders. Hydroids such as the pink Clava multicornis can form colonies on A. nodosum while Dynamena pumila is more often found on F. vesiculosus or F. serratus. Underneath the canopy formed by the brown seaweeds is a diverse community of the red seaweeds Gelidium pusillum, Chondrus crispus, Lomentaria articulata, Membranoptera alata and coralline crusts, but the green seaweeds Enteromorpha intestinalis, Ulva lactuca and Cladophora rupestris can be present. The filamentous red seaweed Polysiphonia lanosa can usually be found growing on A. nodosum. On the rock beneath are the limpet Patella vulgata and the barnacle Semibalanus balanoides, while the crab Carcinus maenas and a variety of winkles including Littorina littorea, Littorina mariae and Littorina obtusata can be found on or among the boulders. The whelk Nucella lapillus can either be found in cracks and crevices or preying on the barnacles.
Situation: This biotope occurs lower on the shore than the Fucus spiralis biotope (MA1-242) although on some shores a narrow zone of F. vesiculosus (unit MA1-23D) may occur immediately above the A. nodosum. MA1-238 is found above the tide-swept F. serratus dominated biotope (unit MA1-239).
Temporal variation: A. nodosum can reach an age of 25 years and the communities are usually very stable. F. vesiculosus or F. serratus can occur in patches where the A. nodosum has been removed.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Cladophora rupestris
Algae Enteromorpha intestinalis
Algae Fucus serratus
Algae Fucus spiralis
Algae Fucus vesiculosus
Algae Ulva lactuca
Invertebrates Ascidiella scabra
Invertebrates Carcinus maenas
Invertebrates Clava multicornis
Invertebrates Dendrodoa grossularia
Invertebrates Halichondria panicea
Invertebrates Nucella lapillus
Invertebrates Patella vulgata
Species scientific name English common name Species group
Cladophora rupestris Algae
Enteromorpha intestinalis Algae
Fucus serratus Algae
Fucus spiralis Algae
Fucus vesiculosus Algae
Ulva lactuca Algae
Ascidiella scabra Invertebrates
Carcinus maenas Invertebrates
Clava multicornis Invertebrates
Dendrodoa grossularia Invertebrates
Halichondria panicea Invertebrates
Nucella lapillus Dog whelk Invertebrates
Patella vulgata Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A1.151 Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A1.151 Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock same
EUNIS Habitat Classification 200202 A1.3142 Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock same
EUNIS Habitat Classification 199910 A1.3142 Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) SLR.F.Asc.T Ascophyllum nodosum, sponges and ascidians on tide-swept mid eulittoral rock same
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