Biodiversity & Conservation

Foliose red seaweeds on exposed or moderately exposed lower infralittoral rock



Image Rohan Holt - Foliose red seaweeds on exposed or moderately exposed lower infralittoral rock. Image width ca XX m.
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Distribution map

IR.EIR.KFaR.FoR recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats

Species indicative of sensitivity

To assess the sensitivity of the biotope, the sensitivity of component species is reviewed. Those species that are considered to be particularly indicative of the sensitivity of the biotope, and for which research has been undertaken in detail are shown below (see selection criteria). The biology of other component species of the biotope is also taken into account wherever information is known to the researcher.

Community Importance Species name Common Name
Important characterizing Delesseria sanguinea Sea beech
Important characterizing Lithophyllum incrustans Encrusting coralline alga
Important other Echinus esculentus Edible sea urchin
Important other Alcyonium digitatum Dead man's fingers
Important other Urticina felina Dahlia anemone
Important other Nemertesia antennina Sea beard
Important other Clavelina lepadiformis Light bulb sea squirt
Important other Calliostoma zizyphinum Painted top shell


The biotope is dominated by foliose and encrusting red algae, such as Delesseria sanguinea, Plocamium cartilagineum, Cryptopleura ramosa, Phycodrys rubens, Dilsea carnosa, Heterosiphonia plumosa and Corallinaceae. Delesseria sanguinea has been selected as an important characterizing species representative of the foliose red algae, as it occurs with the highest percentage frequency (Connor et al., 1997a). Lithophyllum incrustans represents the encrusting Corallinaceae. The edible sea urchin, Echinus esculentus, has been assessed to be a key functional species within the EIR.FoR biotope. Its grazing activity may help maintain the patchy and species rich epiflora/fauna by preventing species from becoming dominant (see Vost, 1983). Other important species include representatives of the sessile epifauna; anemones, soft corals, hydroids, bryozoans, ascidians and grazing molluscs such as Calliostoma zizyphinum. Mobile species such as crabs and fish are not faithful to the biotope although their sensitivity will be integrated where appropriate.

Additional information

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This review can be cited as follows:

Budd, G.C. 2002. Foliose red seaweeds on exposed or moderately exposed lower infralittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 28/11/2015]. Available from: <>