Barnacles and fucoids on moderately wave-exposed Atlantic littoral rock

Rocky shores in the mid- and lower eulittoral zone moderately exposed to wave action, characterised by a mosaic of fucoids and barnacles on bedrock and boulders. The extent of the fucoid cover is typically less than the blanket cover associated with sheltered shores except on the lower shore where there may be dense Fucus serratus. There is typically a lichen zone above and a kelp-dominated community below in the sublittoral zone. Where the moderately exposed lower shore rock is sand-influenced it can be characterised by dense mats of Rhodothamniella floridula. The presence of boulders and cobbles on the shore can increase the micro-habitat diversity, which often results in a greater species richness (crabs, tube-forming polychaetes such as Pomatoceros triquiter, sponges and bryozoans).

Indicators of quality:

Both biotic and abiotic indicators have been used to describe marine habitat quality. These include: the presence of characteristic species as well as those which are sensitive to the pressures the habitat may face; water quality parameters; levels of exposure to particular pressure, and more integrated indices which describe habitat structure and function, such as trophic index, or successional stages of development in habitats that have a natural cycle of change over time.

There are no commonly agreed indicators of quality for this habitat, although particular parameters may have been set in certain situations e.g. protected features within Natura 2000 sites, where reference values have been determined and applied on a location-specific basis.  Indicators which have been developed for the assessment of ecological quality of coastal water bodies for the Water Framework Directive (WFD) that are relevant to this habitat include a consideration of macroalgae species richness, proportions of different taxa of algae present, and the abundance and coverage of the rocky surfaces by typical species. 

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats