EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A3 - Infralittoral rock and other hard substrata > A3.3 - Atlantic and Mediterranean low energy infralittoral rock > A3.32 - Kelp in variable salinity on low energy infralittoral rock > A3.321 - Codium spp. with red seaweeds and sparse Laminaria saccharina on shallow, heavily-silted, very sheltered infralittoral rock

Codium spp. with red seaweeds and sparse Laminaria saccharina on shallow, heavily-silted, very sheltered infralittoral rock

English name: Codium spp. with red seaweeds and sparse Laminaria saccharina on shallow, heavily-silted, very sheltered infralittoral rock

Quick facts

EUNIS habitat type code A3.321
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Description (English)

Very shallow, heavily-silted infralittoral rock characterised by dense stands of Codium spp., together with silt-tolerant red seaweeds, the green seaweed Ulva spp. and often only a sparse covering of the kelp Laminaria saccharina. This biotope appears to have a restricted distribution, being known at present only from the sheltered voes of Shetland, some Scottish lagoons and from the harbours of south-west England. These locations suggest the habitat is likely to be subject to reduced salinity conditions (although the habitat data indicate mostly fully marine records). Dense Codium spp. can occur at very sheltered sites, on cobbles or boulders, often in dense patches interspersed with filamentous red seaweeds Bonnemaisonia hamifera, Antithamnionella spirographidis and Ceramium spp. Where sediment is present the red seaweed Polyides rotundus is commonly found along the rock-sediment interface, and the sponge Dysidea fragilis often occurs on the rock. Other red seaweeds that may be present include Chondrus crispus, Callophyllis laciniata, Gelidium latifolium, Corallina officinalis and coralline crusts. The brown seaweeds Halidrys siliquosa, Desmarestia viridis or Chorda filum may be present in high abundance and although kelp L. saccharina may occur, it is usually sparse. There are no conspicuous fauna that typify this biotope, though polychaetes such as terebellids and spirorbids may occur. The opisthobranch Elysia viridis may be locally abundant on the seaweeds and is known to favour Codium fragilis in particular. Large stands of Codium sp. (generally Common abundance) are accompanied by red seaweeds such as G. latifolium, C. laciniata and A. spirographidis on the rock beneath. Cod has been reported to occur in the shallows of The Fleet, Bembridge Ledges, Pagham Harbour and Jersey (Tittley et al. 1985). In Ireland, species-poor shallow, silted bedrock in the North Water of Mulroy Bay, Co. Donegal, is characterised by Griffithsia corallinoides (Common) and Codium tomentosum (Frequent) forming a narrow band below the kelp zone (unit A3.3132). Cod has not been described from any other sites in Ireland. If Codium spp. is less than Common amongst dense L. saccharina and Chorda filum, it should not be recorded as Cod.
Situation: This biotope occurs on bedrock below a sublittoral fringe of mixed kelp L. saccharina and Laminaria digitata (unit A3.3131) or below a L. saccharina forest (A3.3132) or else on isolated boulders on sediment. It appears to be most frequently found in lagoons. Further information on which species of Codium is present and on the associated fauna is required.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Antithamnionella spirographidis
Algae Bonnemaisonia hamifera
Algae Callophyllis laciniata
Algae Chondrus crispus
Algae Chorda filum
Algae Codium tomentosum
Algae Corallina officinalis
Algae Desmarestia viridis
Invertebrates Dysidea fragilis
Invertebrates Elysia viridis
Algae Griffithsia corallinoides
Algae Halidrys siliquosa
Algae Laminaria digitata
Algae Laminaria saccharina
Algae Polyides rotundus
Species scientific name English common name Species group
Antithamnionella spirographidis Algae
Bonnemaisonia hamifera Algae
Callophyllis laciniata Algae
Chondrus crispus Algae
Chorda filum Algae
Codium tomentosum Algae
Corallina officinalis Algae
Desmarestia viridis Algae
Dysidea fragilis Invertebrates
Elysia viridis Invertebrates
Griffithsia corallinoides Algae
Halidrys siliquosa Algae
Laminaria digitata Algae
Laminaria saccharina Algae
Polyides rotundus Algae

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.LIR.KVS.Cod <I>Codium</I> spp. with red seaweeds and sparse <I>Laminaria saccharina</I> on shallow, heavily-silted, very sheltered 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 A3.321 Codium spp. with red seaweeds and sparse Laminaria saccharina on shallow, heavily-silted, very sheltered infralittoral rock same
EUNIS Habitat Classification 200308 A3.3125 Codium spp. with red seaweeds and sparse Laminaria saccharina on shallow, heavily-silted, very sheltered infralittoral rock same
EUNIS Habitat Classification 200202 A3.3125 Sparse Laminaria saccharina with Codium spp. and sparse red seaweeds on heavily silted very sheltered infralittoral rock same
EUNIS Habitat Classification 199910 A3.3125 Sparse Laminaria saccharina with Codium spp. and sparse red seaweeds on heavily silted very sheltered infralittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) SIR.K.Lsac.Cod Sparse Laminaria saccharina with Codium spp. and sparse red seaweeds on heavily silted very sheltered infralittoral rock same
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