Biodiversity & Conservation

Barnacles and Littorina littorea on unstable eulittoral mixed substrata



Image Paul Brazier - Boulder shore backed by low cliffs (SLR.Bllit) Image width ca 1m in foreground.
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Distribution map

LR.HLR.MusB.Sem.LitX recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats
  • UK_BAP

Text page icon Habitat description

Map icon Distribution of biotope in Britain and Ireland Present on all rocky coasts of Britain but most common on the west coast. Recorded from two sites on the west coast of Ireland.
National importance Rare

Text page icon Description of biotope

For a full description of this biotope including characterizing species, distribution, survey information and references visit JNCC

Banks of cobbles and pebbles which are too unstable or too small to support fucoids are usually colonised by the barnacles Semibalanus balanoides (often with Elminius modestus) with Patella vulgata on larger rocks and often dense aggregations of Littorina littorea. Between the cobbles and pebbles Mytilus edulis often occurs, but always at low abundance (compare with SLR.MytX). Juvenile Carcinus maenas occur between pebbles, and where patches of sediment occur, infaunal species such as the lugworm Arenicola marina and cockle Cerastoderma edule may be present. Fucoids are rare in this biotope. This biotope covers a wide range of wave exposures from mobile exposed and unstable shores to more sheltered stony shores in which fucoids are unable to attach and Mytilus edulis is infrequent. [Further data required to split this biotope into two: open coast cobble sites and estuarine stony sediment sites]. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 97.06: Connor et al., 1997a, b).

Additional information icon Additional information

None entered

This review can be cited as follows:

Hill, J.M. 2002. Barnacles and Littorina littorea on unstable eulittoral mixed substrata. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/11/2015]. Available from: <>