Laminaria digitata and piddocks on sublittoral fringe soft rock

English name: Laminaria digitata and piddocks on sublittoral fringe soft rock

Quick facts

EUNIS habitat type code A3.2113
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Description (English)

Soft rock, such as chalk, in the sublittoral fringe characterised by Laminaria digitata and rock-boring animals such as piddocks Barnea candida and Pholas dactylus, the bivalve Hiatella arctica and worms Polydora spp. Beneath the kelp forest, a wide variety of foliose red seaweeds occur such as Palmaria palmata, Chondrus crispus, Membranoptera alata and Halurus flosculosus. Filamentous red seaweeds often present are Polysiphonia fucoides and Ceramium nodulosum, while coralline crusts cover available rock surface. The bryozoan Membranipora membranacea and the hydroid Dynanema pumila can form colonies on the kelp fronds, while the bryozoan Electra pilosa more often occur on the foliose red seaweeds. Empty piddock burrows are often colonised by the polychaete Sabellaria spinulosa or in more shaded areas the sponges Halichondria panicea and Hymeniacidon perleve. The undersides of small chalk boulders are colonised by encrusting bryozoans, colonial ascidians and the tube-building polychaete Pomatoceros lamarcki. The boulders and any crevices within the chalk provide a refuge for small crustaceans such as Carcinus maenas, the mussel Mytilus edulis or the barnacle Semibalanus balanoides. The echinoderm Asterias rubens is present as well.
Situation: This biotope occurs on moderately exposed soft rock where unit A3.2111 would normally occur. Above it may lie a zone of Fucus serratus on similarly bored soft rock (unit A1.2143) or a variant of one of the F. serratus biotopes (e.g. A1.2141). Lower shore sites influenced by sand may have more Mytilus edulis beneath the seaweed canopy (A1.222) or the sand-binding red seaweed Rhodothamniella floridula (A1.215). Below this biotope a variety of biotopes can occur such as A3.123 on unstable infralittoral cobbles and boulders or even A4.231 in the turbid waters of south-east England where the kelp generally extends to less than 4m BCD.
Temporal variation: The under-storey of foliose and filamentous seaweeds will diminish towards the autumn and regrow in the spring. Since the soft rock does not provide a strong hold for the seaweeds they are easily dislodged during storm periods. After such an event the green seaweeds Enteromorpha spp. and Ulva spp. and/or the red seaweed P. palmata may temporarily cover much of the rock. Eventually a more diverse range of seaweeds and associated animals will re-establish on the rock.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Asterias rubens
Invertebrates Barnea candida
Invertebrates Carcinus maenas
Algae Chondrus crispus
Invertebrates Electra pilosa
Algae Fucus serratus
Invertebrates Halichondria panicea
Algae Halurus flosculosus
Invertebrates Hiatella arctica
Algae Laminaria digitata
Invertebrates Membranipora membranacea
Algae Membranoptera alata
Invertebrates Mytilus edulis
Algae Palmaria palmata
Invertebrates Pholas dactylus
Algae Polysiphonia fucoides
Algae Rhodothamniella floridula
Invertebrates Sabellaria spinulosa
Invertebrates Semibalanus balanoides
Species scientific name English common name Species group
Asterias rubens Invertebrates
Barnea candida Invertebrates
Carcinus maenas Invertebrates
Chondrus crispus Algae
Electra pilosa Invertebrates
Fucus serratus Algae
Halichondria panicea Invertebrates
Halurus flosculosus Algae
Hiatella arctica Invertebrates
Laminaria digitata Algae
Membranipora membranacea Invertebrates
Membranoptera alata Algae
Mytilus edulis Invertebrates
Palmaria palmata Algae
Pholas dactylus Invertebrates
Polysiphonia fucoides Algae
Rhodothamniella floridula Algae
Sabellaria spinulosa Invertebrates
Semibalanus balanoides Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.MIR.KR.Ldig.Pid <I>Laminaria digitata</I> and piddocks on sublittoral fringe soft 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 A3.2113 Laminaria digitata and piddocks on sublittoral fringe soft rock same
EUNIS Habitat Classification 200308 A3.2113 Laminaria digitata and piddocks on sublittoral fringe soft rock same
EUNIS Habitat Classification 200202 A3.2113 Laminaria digitata and piddocks on sublittoral fringe soft rock same
EUNIS Habitat Classification 199910 A3.2113 Laminaria digitata and piddocks on sublittoral fringe soft rock same
MNCR BioMar 97.06 (Britain & Ireland) MIR.KR.Ldig.Pid Laminaria digitata and piddocks on sublittoral fringe soft rock same
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