information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Verrucaria mucosa and/or Hildenbrandia rubra on upper to mid shore cave walls



UK and Ireland classification

UK and Ireland classification


The upper walls and ceilings of the entrances and inner reaches of upper shore caves affected by direct wave action (and therefore moistened by sea spray), characterized by a mosaic of the olive green lichen Verrucaria mucosa and the non-calcified encrusting red alga Hildenbrandia rubra. The black lichen Verrucaria maura and red coralline algae can be present, though not dominating. The fauna in these upper shore caves is generally limited, due to problems of desiccation. However, where conditions remain sufficiently moist, and particularly in crevices and fissures, the barnacle Semibalanus balanoides, the limpet Patella vulgata and winkles Littorina saxatilis may occur, particularly towards the rear of the cave. Although the characterizing species of this biotope also occur on the shore, they do not generally occur in a distinct band other than in moist dark caves. The turf-forming red seaweed Rhodochorton purpureum (syn. Audouinella purpurea) may occasionally occur in low abundance (where Rhodochorton purpureum covers an extensive area, generally on softer rock such as chalk, the biotope should be recorded as RhoCla).

LR.FLR.CvOv.VmucHil generally occurs on upper walls and ceilings towards the rear of dark, moist caves, but can also occur at cave entrances that are directly affected by sea-spray. Where VmucHil occurs at cave entrances and to approximately 5 m into the cave, it is usually found above a zone of Sem and below LR.FLR.CvOvGCv or LR.FLR.CvOvRhoCla. Further into the cave LR.HLR.MusB.Sem is replaced completely by VmucHil. There are no records for VmucHil in soft rock caves. (Information from Connor et al., 2004).

Depth range

Upper shore, Mid shore

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Additional information



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  2. Crump, R. & Moore, J., 1997. Monitoring of upper littoral lichens at Sawdern Point. Report to the Shoreline and Terrestrial Task Group, Sea Empress Environmental Evaluation Committee (SEEEC), July 1997.

  3. Cullinane, J.P., McCarthy, P. & Fletcher, A., 1975. The effect of oil pollution in Bantry Bay. Marine Pollution Bulletin, 6, 173-176.

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  6. Fletcher, A., 1980. Marine and maritime lichens of rocky shores: their ecology, physiology, and biological interactions. In The Shore Environment, vol. 2: Ecosystems (ed. J.H. Price, D.E.G. Irvine & W.F. Farnham), pp. 789-842. London: Academic Press. [Systematics Association Special Volume no. 17(b)].

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  8. Honeggar, R., 2008. Morphogenesis. In Lichen Biology 2edn. (Nash III, T.H. ed.), pp 69-93. Cambridge, Cambrdige University Press

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  14. OBIS, 2016. Ocean Biogeographic Information System (OBIS)., 2016-03-15

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  16. Pugh, P.J.A. & King, P.E., 1985a. Feeding in intertidal Acari. Journal of Experimental Marine Biology and Ecology, 94, 269-280.

  17. Ranwell, D.S., 1968. Lichen mortality due to 'Torrey Canyon' oil and decontamination measures. Lichenologist, 4, 55-56.

  18. Rolan, R.G. & Gallagher, R., 1991. Recovery of Intertidal Biotic Communities at Sullom Voe Following the Esso Bernicia Oil Spill of 1978. International Oil Spill Conference Proceedings: March 1991, Vol. 1991, No. 1, pp. 461-465.doi:

  19. Sancho, L.G., Allan Green, T.G. & Pintado, A., 2007. Slowest to fastest: Extreme range in lichen growth rates supports their use as an indicator of climate change in Antarctica. Flora - Morphology, Distribution, Functional Ecology of Plants, 202 (8), 667-673.

  20. Underwood, A.J., 2006. Why overgrowth of intertidal encrusting algae does not always cause competitive exclusion. Journal of Experimental Marine Biology and Ecology, 330 (2), 448-454.

  21. Underwood, A.J., 1980. The effects of grazing by gastropods and physical factors on the upper limits of distribution of intertidal macroalgae. Oecologia, 46, 210-213.

  22. Wootton, J.T., 1991. Direct and indirect effects of nutrients on intertidal community structure: variable consequences of seabird guano. Journal of Experimental Marine Biology and Ecology, 151, 139-153.


This review can be cited as:

Tyler-Walters, H., 2016. [Verrucaria mucosa] and/or [Hildenbrandia rubra] on upper to mid shore cave walls. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 19-06-2018]. Available from:

Last Updated: 10/03/2016