Biodiversity & Conservation

Fucus serratus, sponges and ascidians on tide-swept lower eulittoral rock


<i>%Fucus serratus%</i>, sponges and ascidians on tide-swept lower eulittoral rock
Distribution map

LR.HLR.FT.FserT recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • UK_BAP

Text page icon Habitat description

Map icon Distribution of biotope in Britain and Ireland This biotope is found on the west (and south-west) coasts of Britain. It has been recorded in the mouths of several river / estuary systems in the south-west of England including Plymouth Sound and the River Fowey. In Wales it exists in Milford Haven and in the Menai Strait. In Scotland it has been recorded in several locations in the Inner and Outer Hebrides, the Orkneys, the Shetlands and on the north-west coast of the mainland.
National importance Scarce

Text page icon Description of biotope

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

Sheltered to extremely sheltered lower eulittoral bedrock, boulders and cobbles that are subject to increased tidal water movement and characterized by the wrack Fucus serratus and a rich assemblage of filter-feeding fauna. This community is encouraged by the increased water movement. It includes species such as the sponges Grantia compressa, Halichondria panicea and Hymeniacidon perleve, which occur frequently on steep and overhanging faces. Underneath the Fucus serratus canopy is a diverse flora of foliose red seaweeds including Mastocarpus stellatus, Lomentaria articulata, Membranoptera alata and Chondrus crispus. The green seaweeds Cladophora spp., Ulva intestinalis and Ulva lactuca and the wrack Ascophyllum nodosum are present though usually in small numbers. On the rock underneath the seaweed canopy, species such as the limpet Patella vulgata, the barnacles Semibalanus balanoides and Balanus crenatus and the whelk Nucella lapillus can be found though in lower abundance than higher up the shore. Also present on the rock are the tube-forming polychaetes Pomatoceros triqueter and spirorbids and more mobile species such as the winkle Littorina mariae, the top shell Gibbula cineraria and the crab Carcinus maenas. Lastly, several species of bryozoans are usually present including Electra pilosa, Flustrellidra hispida and Alcyonidium gelatinosum, all competing for space with the hydroid Dynamena pumila, which can form dense populations on the Fucus serratus fronds. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 04.05: Connor et al., 2004.).

Additional information icon Additional information

This review can be cited as follows:

Marshall, C.E. 2005. Fucus serratus, sponges and ascidians on tide-swept lower eulittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 27/11/2015]. Available from: <>