Biodiversity & Conservation

Barnacles and fucoids (moderately exposed shores)


Barnacles and fucoids (moderately exposed shores)
Distribution map

LR.MLR.BF recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats

Text page icon Habitat description

Map icon Distribution of biotope in Britain and Ireland In Britain and Ireland, barnacle and fucoid biotopes are widespread on bedrock and boulder shores exposed to strong to moderate wave action and on steeply sloping or vertical rock on more sheltered shores.
National importance Widespread

Text page icon Description of biotope

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

On moderately exposed rocky shores the extent of fucoid cover is typically less than that found on sheltered shores (SLR.F). The fucoids form a mosaic with barnacles on bedrock and boulders, rather than the blanket cover associated with sheltered shores, except on the lower shore where there may be dense Fucus serratus (MLR.Fser). Beneath the band of lichens at the top of the shore (LR.YG and LR.Ver) the channel wrack Pelvetia canaliculata typically occurs overgrowing the black lichen Verrucaria spp. with sparse barnacles (MLR.PelB). Below, barnacles and limpets Patella may cover extensive areas of rock (ELR.BPat), particularly on steep or vertical rock. In the absence of ELR.BPat, the spiral wrack Fucus spiralis may occur (SLR.Fspi). On the mid shore the bladder wrack Fucus vesiculosus generally forms a mosaic with barnacles (MLR.FvesB). Finally, the serrated wrack Fucus serratus, dominates the lower shore (MLR.Fser); a number of sub-biotopes have been described: lower shore bedrock and boulders may be characterized by mosaics of Fucus serratus and turf-forming red algae (MLR.Fser.R); where the density of Fucus serratus is greater (typically common - superabundant) and the abundance of red algae less MLR.Fser.Fser should be recorded. The presence of boulders and cobbles on the shore can increase the micro-habitat diversity which often results in a greater species richness. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 97.06: Connor et al., 1997a, b).

Additional information icon Additional information

This review can be cited as follows:

Hill, J.M. 2000. Barnacles and fucoids (moderately exposed shores). 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: <>