Mousa was identified as a candidate Special Area of Conservation (cSAC) because of the presence of a large breeding colony of common seals, Phoca vitulina, a species listed in Annex II of the EC Habitats Directive; and for the presence of âreefsâ and âsubmerged and partly submerged sea cavesâ, habitats that are listed in Annex 1 of the EC Habitats Directive. Mousa cSAC supports one of the largest groups of common seals in Shetland and one of the most northerly groups in the UK. The reefs and sea caves within Mousa cSAC are considered highly natural and representative of the Shetland environment.
The seaward boundary extends to a minimum distance of 500m offshore, using the simplest straight-line boundaries possible. The boundary for the cSAC also includes all offshore rocks and skerries (Figure 1.1). The intertidal areas up to mean high water springs around the island are also included within the cSAC.
The present survey visited the island of Mousa cSAC in August and September 2003 with the aim of providing a comprehensive broad scale intertidal and subtidal biotope distribution map of Mousa cSAC. Particular emphasis was placed upon the mapping and recording of the reef and cave communities present on the island. Intertidal surveys of the island were supplemented by the use of acoustic ground discrimination system (AGDS) mapping techniques of the subtidal area. Photography, video footage and illustrations were used to illustrate habitats, communities and species. Video derived biological data has not been entered into Marine Recorder.
