Classification

Description

GB distribution

Compiled by: Leigh Jones, Joint Nature Conservation Committee, Monkstone House, City Road, Peterborough PE1 IJY, UK.

Derived, in part, from: the UK marine biotope classification (Connor et al. 1997a) and a review undertaken for the UK Marine SACs Project (Holt et al. 1998).

Many wave-exposed boulder scar grounds in the eastern basin of the Irish Sea (and as far south as Cornwall), are characterised by reefs of Sabellaria alveolata, the tubes of which are built from the mobile sand surrounding the boulders and cobbles. The tubes formed by Sabellaria alveolata form large reef-like hummocks, which serve to stabilise the boulders. Other species in this biotope include the barnacles Semibalanus balanoides, Balanus crenatus and Elminius modestus and the molluscs Patella vulgata, Littorina littorea, Nucella lapillus and Mytilus edulis. Low abundances of algae tend to occur in areas of eroded reef. The main algal species include Porphyra spp., Mastocarpus stellatus, Ceramium spp., Fucus vesiculosus, Fucus serratus, Enteromorpha spp. and Ulva spp. On exposed surf beaches in the south-west Sabellaria forms a crust on the rocks, rather than the classic honeycomb reef, and may be accompanied by the barnacle Balanus perforatus (typically common). On wave-exposed shores in Ireland, the brown alga Himanthalia elongata can also occur.

Note: Sabellaria alveolata reefs may also form in the subtidal (e.g. in the Severn estuary), but these are not considered here.

(from MNCR database in February 1999)

Habitat requirements

Species composition and biodiversity

Ecological relationships

Sensitivity to human activities

Conservation and protection status

References