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.

The hydroid Obelia longissima is particularly characteristic to this biotope. The common periwinkle is part of the biotope name and has therefore also been listed as an important characterizing species. Ulva intestinalis, although not a characterizing species per se, is representative of other ephemeral green algae that may be found in LR.H. It also provides a food source for the common periwinkle. The common mussel Mytilus edulis has been included as another important species since it was found in almost all records of the biotope, often in abundance, and mussel patches may provide some stability to this otherwise unstable and transient biotope. The acorn barnacle Semibalanus balanoides is likely to be found attached to stones and shells. It has been listed as important 'other' since it may be common is some LR.H pools.

The MNCR reported 129 species from this biotope, although not all species occur in all examples of the biotope (JNCC, 1999).