Size: 38.64 hectares

% of total area of SSSI's: 9.51%

Designated features: Common Tern 

General Description

Samson SSSI is the largest uninhabited island in the Isles of Scilly. Situated south-west of Tresco, the SSSI includes the nearby small islands of Puffin Island, Stony Island, Green Island and White Island. The SSSI is dominated by two granite hills, the largest South Hill rising to 40m above sea level and is separated by a narrow neck of vegetated sand and shingle. At the north-eastern end of North Hill the blown sands has also formed a small dune system.

At the summits of both hills, where the vegetation is exposed to south-west prevailing winds, ‘waved’ maritime heath dominated by Heather and Bell Heather are present. This heathland is interspersed with dense stands of Bracken and Bramble where early Neolithic settlers disrupted the soil to construct several Neolithic tumuli. This scrub descends down both the slopes on deep soil, but holds good populations of Bluebell in Spring, along with Red Campion and the nationally rare Balm-leaved Figwort. The sand and shingle bar supports colonising maritime species including Sea Beet and Thrift, along with uncommon species such as Sea Spurge. The dune system to the north east is dominated by Marram Grass with its associated strandline particularly important for the nationally rare Shore Dock.

Interestingly, some of the vegetation on Samson SSSI reflects the long period of human occupation up until 1855, particularly on South Hill will you will find specimens of Tamarisk, Elder and Primrose which can be seen around the old ruins and walls. Samson SSSI and the surrounding small islands are particularly important for their breeding seabirds, being notified for their nationally important numbers of Common Tern and occasional breeding records for Roseate Tern. The colony of Lesser Black-backed Gull on South Hill is of national importance and is also one of the largest colonies of this species on Scilly. Here there are also present small numbers of Great Black-backed Gull, Herring Gull and Shag.

Practical Management

Samson SSSI is the most used and visited uninhabited island in the archipelago. The pressure on the islands and its wildlife is heavily tested. We try to balance the needs of visitors, whilst trying to maintain a space for nature. Well maintained paths that steer visitors away from the main breeding colonies of seabirds is key, as in the recent past the island has lost its colony of Common Tern, in part due to disturbance as visitors walked across the summit of North Hill unimpeded. Archaeology is also an important component of the practical management we carry out, with the island being inhabited from Neolithic times through to the mid-nineteenth century there are many scheduled ancient monuments to be admired, but which also require annual clearance.  Annual clearance of areas of scrub to permit ground nesting birds to nest, whilst maintaining a degree of cover to minimise disturbance and hide from predators are among the management tasks we undertake.

We also attempt to keep the sand and shingle neck clear of the endless tide of marine debris that is washed up daily with the tide....a job that is never ending!