Methods used during these surveys included a desk-based study, a digital aerial survey and ground-based counts. The digital aerial survey involved an aircraft flying systematic 2km spaced transects through the survey area recording high definition video along four 200m strips thus achieving 10% sampling coverage of the area. The images recorded were processed, and bird and mammal species were identified by analysts post survey and strip transect analysis undertaken to derive abundance estimates for the study area. Density surface modelling was undertaken for fulmars, gannets and auk species. 1.3 Ground-based counts involved an ornithologist undertaking a bird and marine mammal survey from 14 vantage points along the west coast of Lewis. These counts were co-ordinated as much as possible with the aerial survey, and were used to gain more information about more difficult to identify species, or undertaken in places known to be important for seabirds but likely to be missed by the aerial survey. A further vantage point study covering the majority of Loch Roag was also undertaken, covering areas outside the aerial survey study area.