Vegetated (ephemeral) Atlantic littoral mixed sediment

This habitat comprises littoral mixed substrata (pebbles and cobbles overlying sand or mud) that are subject to variations in salinity and/or siltation, characterised by dense blankets of ephemeral green and red seaweeds. This habitat is found primarily on enclosed stony shores sheltered from wave action with weak to moderate tidal streams and often subject to variable levels of salinity. It is found predominately in the mid shore zone above, or at the same level as, the biotope dominated by the barnacles S. balanoides and/or E. modestus and Littorina spp. If it is found in the upper shore region it can be backed by saltmarsh species such as Salicornia sp. and Spartina sp. Below are biotopes dominated by the wracks Fucus serratus or Fucus vesiculosus or by M. edulis or by the polychaete Hediste diversicolor and the tellin Macoma balthica depending on the substratum.

Eulittoral pebble and boulder beaches in the Macaronesian archipelagos are mainly located at the mouth of steep brook valleys (Barrancos). At depths where wave action is only slight, stable ecosystems can develop with species-rich plant covers, lodging many different animals. In the eulittoral the biota is reduced to a few  small turf green and red seaweeds (usually Ulva species and Gelidium pusillum), but in the infralittoral, several species of red seaweeds occur, such as Ellisondia officinalis, Halophytis incurva and members of the family Liagoraceae, also brown seaweeds, like Stypocaulon scoparium and Sargassum spp. Among the faunal components, limpets (Patella spp.), periwinkles (Osilinus spp.) and crabs (Pecnon gibbessi) are common species. 

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.

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats