Sanday is one of the northernmost islands in the Orkney Islands archipelago. In 2005 Sanday was designated as a Special Area of Conservation (SAC), based on the island’s role in supporting one of the largest colonies of common seals Phoca vitulina in Scotland, and for its ‘subtidal sandbanks’, ‘intertidal mud and sandflats’ and ‘rocky reefs’. This designation built upon the existing East Sanday Coast Site of Special Scientific Interest (SSSI), notified in 1999, which recognised the importance of varied and extensive intertidal sediment flats and rocky reef habitats in supporting common seals and a range of ornithological and botanical interests.
The aim of the current study (2008) was to initiate site condition monitoring of the marine habitat features present within the SAC and SSSI, establishing a baseline biological dataset against which to underpin future condition assessments. In the subtidal an extensive drop-down video survey of reef and sediment biotopes (different habitats with their recurring characteristic species communities) guided a subsequent targeted programme of semi-quantitative diver sampling and quantitative benthic infaunal sampling. In the intertidal, relocatable transects were established at ten locations deemed to best represent the shore types present.