Together with Linga Holm, which lies 2km to the south, these islands provide an internationally important breeding site for Grey seals. In addition to the seals, the island supports breeding seabirds including a large colony of cormorants, Arctic tern and Fulmar. The Scottish Wildlife Trust purchased this reserve in 2016 to protect this important seal pupping site.
Linga Holm (known locally as Midgarth Holm) is home to a number of birds including Ringed plover, Meadow pipit, Rock pipit, Snipe, Skylark and Red-throated diver. Seabirds include Arctic tern, Fulmar, Arctic skua and Great skua, Herring and Common gull, Great black-backed gull and Lesser black-backed gull.
The island is uninhabited by people today, but has many archaeological sites, including several kelp-working areas. The Scottish Wildlife Trust purchased the island in 1999 to safeguard the seal population and other wildlife. During the time when the Grey seals pup (between September to November inclusive) disturbance to the breeding beaches must be avoided.