When undertaking an appropriate assessment of impacts at a site, all features of European importance (both primary and non-primary) need to be considered.
Annex I habitats that are a primary reason for selection of this site
|Papa Stour is an example of very exposed reefs on hard rocks in the extreme north of Scotland. The rocky coastline of Papa Stour is among the most exposed in the UK, and the island and the adjacent mainland are fringed entirely by sublittoral bedrock and boulder reefs reaching depths of more than 30 m. The underwater terrain is rugged, with rock walls, slopes, gullies, ledges, ridges and boulder slopes, which support a diverse range of plant and animal communities. The extensive kelp forests on these reefs have a rich associated algal community at shallow depths because wave action prevents grazing by sea-urchins in some exposed areas. Kelp extends to depths of up to 28 m in the clear waters surrounding the island. Communities on circalittoral rock are characteristic of northern parts of the UK, with dominant species including the soft coral Alcyonium digitatum, the featherstar Antedon bifida, encrusting coralline algae, and the serpulid worm Pomatoceros triqueter. Wave-exposed gullies have rich, surge-tolerant communities, with turfs of the jewel anemone Corynactis viridis, ascidians and bryozoans. In the strong tidal streams of the Sound of Papa, boulder reefs and bedrock ridges are dominated by scour-tolerant organisms such as the hydroid Abietinaria abietina and the brittlestar Ophiocomina nigra.|
|8330 Submerged or partially submerged sea caves|
|Papa Stour has excellent examples of caves, tunnels and arches occurring in cold northerly waters. In very exposed sea conditions the caves support rich communities that illustrate the effects of surge, scour and changes in light conditions. The cave walls have extensive faunal turfs, and among the more unusual species present is the northern anemone Phellia gausapata. The rare, surge-tolerant alga Schmitzia hiscockiana is found on boulders in cave entrances. Further diversity is due to the presence of sheltered gullies and tunnels where the community zonation is influenced by tidal flows.|
Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site
Annex II species that are a primary reason for selection of this site
Annex II species present as a qualifying feature, but not a primary reason for site selection
Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.