EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A3 - Infralittoral rock and other hard substrata > A3.2 - Atlantic and Mediterranean moderate energy infralittoral rock > A3.22 - Kelp and seaweed communities in tide-swept sheltered conditions > A3.224 - Laminaria saccharina with foliose red seaweeds and ascidians on sheltered tide-swept infralittoral rock

Laminaria saccharina with foliose red seaweeds and ascidians on sheltered tide-swept infralittoral rock

English name: Laminaria saccharina with foliose red seaweeds and ascidians on sheltered tide-swept infralittoral rock

Quick facts

EUNIS habitat type code A3.224
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Description (English)

Sheltered, tide-swept rock in south-western Britain tends to be restricted to estuarine conditions, where variable salinity and increased turbidity have a significant effect on the biota. Due to the turbidity of the water, the infralittoral zone is restricted to very shallow depths. Unlike the tide-swept channels in sealochs, which support a mixed kelp canopy, the rock in these estuaries is characterised by Laminaria saccharina alone, occurring in relatively low abundance (Frequent). The brown alga Desmarestia ligulata can occur in this biotope, though never dense, along with the non-native brown seaweed Sargassum muticum. Beneath the sparse kelp, cobbles and boulders, often surrounded by sediment, are encrusted by fauna and often a dense turf of red seaweed. The foliose red seaweeds associated with this biotope include Callophyllis laciniata, Nitophyllum punctatum, Kallymenia reniformis, Gracilaria gracilis, Gymnogongrus crenulatus, Hypoglossum hypoglossoides, Rhodophyllis divaricata, Chylocladia verticillata, Cryptopleura ramosa and Erythroglossum laciniatum as well as the filamentous Ceramium nodulosum and Pterothamnion plumula. Green seaweeds Ulva lactuca, Bryopsis plumosa and Cladophora spp. may be locally abundant. The dominating faunal species vary from site to site but include sponges such as Halichondria panicea, Esperiopsis fucorum, Dysidea fragilis and Hymeniacidon perleve as well as ascidians, particularly Dendrodoa grossularia and Morchellium argus, which can cover the rocks. Also present is the anthozoan Anemonia viridis, the barnacle Balanus crenatus and the tube-building polychaete Pomatoceros triqueter. The hydroid Plumularia setacea can cover rocks and seaweed fronds Of the range of solitary ascidians found in the north-west, only Ascidiella aspersa tends also to be present in these south-western inlets. There is also a general absence of echinoderms. Where there is vertical rock present, it tends to support more fauna, including barnacles Balanus crenatus, the ascidians Clavelina lepadiformis and Botryllus schlosseri and sometines the featherstar Antedon bifida. Where soft rock allows, such as the limestone in Plymouth Sound, rock-boring organisms such as Polydora sp. may be locally abundant. Sheltered, tide-swept rock is generally restricted to the narrows or tidal rapids of marine inlets. The clear tide-swept waters of Scottish sealochs are significantly different to the marine inlets of south-west Britain. This biotope deals with the latter.
Situation: This biotope generally occurs on rocky outcrops interspersed by sediment areas. Where the rock extends into deeper water, beyond the limit of kelp, sponges and ascidians tend to dominate these sheltered, tide-swept circalittoral sites (A4.251); also Alcyonium digitatum with sponges and Nemertesia antennina (A4.131).

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Bryopsis plumosa
Algae Callophyllis laciniata
Algae Chylocladia verticillata
Algae Cryptopleura ramosa
Algae Desmarestia ligulata
Algae Erythroglossum laciniatum
Algae Gracilaria gracilis
Algae Gymnogongrus crenulatus
Algae Hypoglossum hypoglossoides
Algae Kallymenia reniformis
Algae Laminaria saccharina
Algae Nitophyllum punctatum
Algae Pterothamnion plumula
Algae Rhodophyllis divaricata
Algae Sargassum muticum
Algae Ulva lactuca
Invertebrates Alcyonium digitatum
Invertebrates Anemonia viridis
Invertebrates Antedon bifida
Invertebrates Ascidiella aspersa
Invertebrates Balanus crenatus
Invertebrates Botryllus schlosseri
Invertebrates Clavelina lepadiformis
Invertebrates Dendrodoa grossularia
Invertebrates Dysidea fragilis
Invertebrates Esperiopsis fucorum
Invertebrates Halichondria panicea
Invertebrates Nemertesia antennina
Invertebrates Plumularia setacea
Invertebrates Pomatoceros triqueter
Species scientific name English common name Species group
Bryopsis plumosa Algae
Callophyllis laciniata Algae
Chylocladia verticillata Algae
Cryptopleura ramosa Algae
Desmarestia ligulata Algae
Erythroglossum laciniatum Algae
Gracilaria gracilis Algae
Gymnogongrus crenulatus Algae
Hypoglossum hypoglossoides Algae
Kallymenia reniformis Algae
Laminaria saccharina Algae
Nitophyllum punctatum Algae
Pterothamnion plumula Algae
Rhodophyllis divaricata Algae
Sargassum muticum Algae
Ulva lactuca Algae
Alcyonium digitatum Invertebrates
Anemonia viridis Invertebrates
Antedon bifida Invertebrates
Ascidiella aspersa Invertebrates
Balanus crenatus Invertebrates
Botryllus schlosseri Invertebrates
Clavelina lepadiformis Invertebrates
Dendrodoa grossularia Invertebrates
Dysidea fragilis Invertebrates
Esperiopsis fucorum Invertebrates
Halichondria panicea Invertebrates
Nemertesia antennina Invertebrates
Plumularia setacea Invertebrates
Pomatoceros triqueter Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.MIR.KT.LsacT <I>Laminaria saccharina</I> with foliose red seaweeds and ascidians on sheltered tide-swept infralittoral rock 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 A3.224 Laminaria saccharina with foliose red seaweeds and ascidians on sheltered tide-swept infralittoral rock same
EUNIS Habitat Classification 200308 A3.3124 Laminaria saccharina, foliose red seaweeds, sponges and ascidians on tide-swept infralittoral rock same
EUNIS Habitat Classification 200202 A3.3124 Laminaria saccharina, foliose red seaweeds, sponges and ascidians on tide-swept infralittoral rock same
EUNIS Habitat Classification 199910 A3.3124 Laminaria saccharina, foliose red seaweeds, sponges and ascidians on tide-swept infralittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) SIR.K.Lsac.T Laminaria saccharina, foliose red seaweeds, sponges and ascidians on tide-swept infralittoral rock same
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