Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock

English name: Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock

Quick facts

EUNIS habitat type code A3.121
Bern Convention Included in a Resolution 4 habitat type at a higher level (A3)

Description (English)

Exposed low-lying reefs in the sublittoral fringe or upper infralittoral (generally above 5m depth), mainly in the southwest and west, dominated by the kelp Saccorhiza polyschides. This opportunistic coloniser replaces Laminaria digitata or Laminaria hyperborea as the dominant kelp, following 'disturbance' of the canopy. This may be the result of storms, when loose sediment and even cobbles or boulders are mobilised, scouring most seaweeds and animals from the surrounding rock. As S. polyschides is essentially a summer annual (occasionally it lasts into a second year), it is also particularly common close to rock/sand interfaces which become too scoured during winter months to prevent the longer-living kelps from surviving. As a result of the transient nature of this biotope, its composition is varied; it may contain several other kelp species, including L. digitata, Laminaria saccharina and Alaria esculenta, at varying abundances. Laminaria spp. sporelings can also be a prominent feature of the site. Beneath the kelp, (scour-tolerant) red seaweeds including Corallina officinalis, Kallymenia reniformis, Plocamium cartilagineum, Chondrus crispus, Dilsea carnosa and encrusting coralline algae are often present. Foliose red seaweeds such as Callophyllis laciniata, Cryptopleura ramosa and Palmaria palmata also occur in this biotope. P. palmata and Delesseria sanguinea often occur as epiphytes on the stipes of L. hyperborea, when it is present. The foliose green seaweed Ulva spp. is fast to colonise newly cleared areas of rock and is often present along with the foliose brown seaweed Dictyota dichotoma. Due to the disturbed nature of this biotope, fauna are generally sparse, being confined to encrusting bryozoans and/or sponges, such as Halichondria panicea and the gastropod Gibbula cineraria.
Situation: On some shores (for example in Cornwall and south-west Ireland), S. polyschides competes so effectively with the other laminarians that it forms a well-defined zone in shallow water, between the L. digitata (unit A3.3131) and L. hyperborea zones (units A3.115 and A3.214). Elsewhere, it is found at sites that have been physically disturbed, removing areas of established kelp (L. hyperborea) thus allowing this opportunistic biotope to develop over a short space of time.
Temporal variation: There may be significant variations in this biotope over time, as by its very nature, it is dominated by many fast-growing annual seaweeds. The foliose green seaweed Ulva sp. is fast to colonise newly cleared areas of rock and can be present as a dense growth on the rock around the Saccorhiza polyschides. Similarly, large patches of Laminaria spp. sporelings may be present at times.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Alaria esculenta
Algae Callophyllis laciniata
Algae Chondrus crispus
Algae Corallina officinalis
Algae Cryptopleura ramosa
Algae Delesseria sanguinea
Algae Dictyota dichotoma
Algae Dilsea carnosa
Invertebrates Gibbula cineraria
Invertebrates Halichondria panicea
Algae Kallymenia reniformis
Algae Laminaria digitata
Algae Laminaria hyperborea
Algae Laminaria saccharina
Algae Palmaria palmata
Algae Plocamium cartilagineum
Algae Saccorhiza polyschides
Species scientific name English common name Species group
Alaria esculenta Algae
Callophyllis laciniata Algae
Chondrus crispus Algae
Corallina officinalis Algae
Cryptopleura ramosa Algae
Delesseria sanguinea Algae
Dictyota dichotoma Algae
Dilsea carnosa Algae
Gibbula cineraria Invertebrates
Halichondria panicea Invertebrates
Kallymenia reniformis Algae
Laminaria digitata Algae
Laminaria hyperborea Algae
Laminaria saccharina Algae
Palmaria palmata Algae
Plocamium cartilagineum Algae
Saccorhiza polyschides Algae

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 IR.HIR.KSed.Sac <I>Saccorhiza polyschides</I> and other opportunistic kelps on disturbed sublittoral fringe 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 A3.121 Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock same
EUNIS Habitat Classification 200308 A3.231 Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock same
EUNIS Habitat Classification 200202 A3.231 Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock same
EUNIS Habitat Classification 199910 A3.231 Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock same
MNCR BioMar 97.06 (Britain & Ireland) MIR.SedK.Sac Saccorhiza polyschides and other opportunistic kelps on disturbed upper infralittoral rock same
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