Filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable-salinity Atlantic infralittoral rock
Quick facts
EUNIS habitat type | code MB121J |
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Relation to | Resolution 4 habitat type (used for designation of Emerald sites) |
Description (English)
Tide-swept infralittoral rock subject to variable salinity and turbid waters occurs in the mid to upper reaches of the rias of south-west Britain, where riverine freshwater input reduces the salinity. Very shallow rock under these conditions is characterised by a covering of filamentous red seaweed such as Callithamnion spp., Antithamnion spp., Ceramium spp., Griffithsia devoniensis, Pterothamnion plumula and Polysiphonia fucoides, as well as the filamentous green seaweed Cladophora spp. Foliose red seaweeds such as Hypoglossum hypoglossoides, Cryptopleura ramosa and Erythroglossum laciniatum commonly occur, as does the foliose green seaweed Ulva lactuca. Although Laminaria saccharina is often present it is usually in very low abundance (Occasional). The fluctuating salinity limits the number of species able to exist in this habitat. The animal community is dominated by the sponges Halichondria panicea and Hymeniacidon perleve and the barnacle Balanus crenatus. The ascidians Clavelina lepadiformis and Dendrodoa grossularia can be locally abundant at some sites. The crab Carcinus maenas is usually present, as is the mussel Mytilus edulis. The bryozoan Bugula plumosa is sometimes present. Where vertical rock is present, the seaweeds Ceramium nodulosum, P. plumula, C. ramosa, H. hypoglossoides and E. laciniatum are typically found.
Situation: This biotope is usually found amidst sediment or rock and as such there is no defined zonation of the surrounding biotopes. Shallow sediments nearby may support seagrass beds ( Zostera spp.) or infaunal-dominated sediments (unit MB3-2). Nearby, deeper tide-swept rock may support circalittoral communities dominated by sponges, hydroids and ascidians on stable rock (unit MC1-2411) or dense bryozoans on mixed substrata (units MC1-217 & MC1-219).
Source: EUNIS habitat classification
Legal status
Relation to other habitat types mentioned in legal instruments
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Species scientific name | English common name | Species group |
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Cryptopleura ramosa | Algae | |
Erythroglossum laciniatum | Algae | |
Griffithsia devoniensis | Algae | |
Hypoglossum hypoglossoides | Algae | |
Laminaria saccharina | Algae | |
Polysiphonia fucoides | Algae | |
Pterothamnion plumula | Algae | |
Ulva lactuca | Algae | |
Balanus crenatus | Invertebrates | |
Bugula plumosa | Invertebrates | |
Carcinus maenas | Invertebrates | |
Clavelina lepadiformis | Invertebrates | |
Dendrodoa grossularia | Invertebrates | |
Halichondria panicea | Invertebrates | |
Mytilus edulis | Invertebrates |
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 2007 (revised descriptions 2012) | A3.225 | Filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable-salinity infralittoral rock | same |
History
Classification | Code | Habitat type name | Relationship type | Comment |
---|---|---|---|---|
EUNIS Habitat Classification 200410 | A3.225 | Filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable-salinity infralittoral rock | same | |
EUNIS Habitat Classification 200308 | A3.314 | Laminaria saccharina on reduced or low salinity infralittoral rock | narrower | |
EUNIS Habitat Classification 200308 | A3.3141 | Filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable-salinity infralittoral rock | same | |
EUNIS Habitat Classification 200202 | A3.3141 | Sparse Laminaria saccharina with dense filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable salinity infralittoral rock | same | |
EUNIS Habitat Classification 199910 | A3.3141 | Sparse Laminaria saccharina with dense filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable salinity infralittoral rock | same | |
MNCR BioMar 97.06 (Britain & Ireland) | SIR.K.LsacRS.FiR | Sparse Laminaria saccharina with dense filamentous red seaweeds, sponges and Balanus crenatus on tide-swept variable salinity infralittoral rock | same |