Biodiversity & Conservation

Laminaria digitata and piddocks on sublittoral fringe soft rock



Image David George - View across shore showing extensive kelp beds on chalk. Image width ca 4 m.
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Distribution map

IR.MIR.KR.Ldig.Pid 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 Recorded from a few sites on the south Kent coast and north Wales.
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

Soft rock, such as chalk, in the sublittoral fringe characterized by Laminaria digitata and rock-boring animals such as piddocks (Barnea candida, Pholas dactylus and Petricola pholadiformis), the bivalve Hiatella arctica and worms Polydora spp. Beneath the kelp forest, a wide variety of red seaweeds, including Corallina officinalis, Palmaria palmata, Chondrus crispus, Membranoptera alata and Halurus flosculosus, may occur. Empty piddock burrows are often colonised by the anemones Sagartia elegans or by the sand-tube building worm Sabellaria spinulosa. The undersides of small chalk boulders are colonised by encrusting bryozoans, colonial ascidians and the keel worm Pomatoceros lamarcki. The boulders and any crevices within the chalk provide a refuge for small crustaceans such as Carcinus maenas, young Cancer pagurus, Pagurus bernhardus and Porcellana platycheles. (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. 2008. Laminaria digitata and piddocks on sublittoral fringe soft rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 01/12/2015]. Available from: <>