The St. Kilda Special Area of Conservation (SAC) has been selected to provide protection for reefs, sea cliffs and sea caves.
The St Kilda archipelago is a westerly outlier of the Outer Hebrides and represents extremely wave-exposed reefs. The islands are formed of hard, igneous rock, which forms steep and vertical reefs around the entire island group. Littoral reef communities extend several metres above mean high water because of wave exposure, and populations of the uncommon exposed-shore fucoid Fucus distichus are present. Rock faces may extend sublittorally to reach depths of 50 m and support communities characteristic of very exposed conditions on rock walls, overhangs and ledges, in surge gullies and amongst boulders. The clarity of the Atlantic sea water is high, and dense kelp forests may occur as deep as 35 m. Sublittoral fringe biotopes which, elsewhere, are found only at low-water mark, may here reach depths of 12 m. Circalittoral rock is dominated by diverse communities of anemones, sponges and soft corals, with different species of sponge, hydroid and bryozoan occurring in surge gullies and caves .
This site now has fisheries management measures in place.
Read our response to the 2015 consultation on management measures for this site here:
Save Scottish Seas campaign members have assessed the management proposals and fully support the proposed management approach to prohibit the use of mobile demersal fishing gear throughout the site.
We agree with the management advice to remove/avoid pressure for the reefs, as any activity which has abrasive impacts or which causes an increase in suspended sediment on or near the reefs may risk the health of the bed and the biodiversity it supports. Bedrock and stony reef habitats are important seabed structures, providing a refuge and nursery grounds for juvenile fish and shellfish.
The use of static gear on and around the reefs should be monitored closely to ensure that this practice is conducted sustainably and without causing damage to the reef structure or its typical species. An Appropriate Assessment may be necessary if deemed to have any likely significant effects. St Kilda is a UNESCO World Heritage Site and boasts internationally important colonies of many species of seabird and an extensive history and cultural heritage. Static gear use should be subjected to an Appropriate Assessment and should be monitored to ensure that foraging seabirds,
cetaceans and basking sharks are not at risk from entanglement in creel lines. Should any evidence
arise to indicate that damage was being caused, static gear should be prohibited from this SAC. Set nets should be prohibited from this site to prevent entanglement of foraging seabirds.
 St. Kilda SAC site summary, JNCC