Biodiversity & Conservation

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

A forest or park of the fast-growing, opportunistic kelps Laminaria saccharina and/or Saccorhiza polyschides often occurs on seasonally unstable or scoured infralittoral rock. The substratum varies from large boulders in exposed areas to smaller boulders and cobbles in areas of moderate wave exposure or nearby bedrock. In these cases, movement of the substratum during winter storms prevents a longer-lived forest of Laminaria hyperborea from becoming established. This biotope may also develop on bedrock where it is affected by its close proximity to unstable substrata. Other fast-growing algae such as Ulva spp., Alaria esculenta, Desmarestia spp. and Chorda filum are often present. This biotope can be found below the Laminaria hyperborea zone (EIR.LhypFa or EIR.LhypR), especially where close to a rock/ sand interface (subjected to sand scour in winter?). Some Laminaria hyperborea plants may occur in this biotope, but they are typically small since the plants do not survive many years. In St Kilda, this biotope is present on steep/vertical rock between the sublittoral fringe of Alaria esculenta and the Laminaria hyperborea forest below. In such places this biotope occurs because intense wave action in winter storms is too severe to allow Laminaria hyperborea to develop and remain in shallow water. (Information taken from the Marine Biotope Classification for Britain and Ireland, Version 97.06: Connor et al., 1997a, b). NB. Laminaria saccharina is now considered to be a synonym of Saccharina latissima.

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