Biodiversity & Conservation

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.

• Corallina officinalis
• Lithophyllum incrustans

Corallina officinalis is the dominant characterizing species within the biotope and provides substratum and refuges for a diverse epifauna. Therefore, the community is dependant on the presence of Corallina officinalis and it has been included as key structuring. Encrusting coralline algae such as Lithophyllum incrustans are characteristic of the biotope. Gastropods Littorina littorea, Patella vulgata and Gibbula cineraria may graze pools in the eulittoral zone to such an extent that they are devoid of any foliose red algae and are reduced to encrusting coralline algae. They have been included as important structural species. Epiphytic grazers, such as amphipods, isopods small gastropods probably keep the turf free of epiphytic algae and are important structural species. Reference has been made to reviews of Hyale prevostii to represent the sensitivity of amphipods and small crustaceans.

The MNCR recorded ca 577 species in 176 records of this biotope, although not all species occurred in all records of the biotope (Connor et al., 1997b; JNCC, 1999).