GWYNEDD THE SKERRIES SSSI
Date of notification: 1957,1984
National Grid Reference: SH269949
OS 1:50000 Sheet number: 114
1:25000 Sheet number: SH39
Area: 17 hectares (42 acres)
A group of small rocky islets used by seabirds and grey seals. The Skerries used to be one of the major breeding sites for terns particularly arctic terns in the British Isles. Numbers declined from the several thousand pairs recorded in 1905 to being completely deserted in the 1960s. However, arctic terns have returned and 150 pairs bred there in 1983. A gullery, principally of herring and lesser black - backed gulls 650/700 pairs in 1983 is also present. Other breeding species include puffin (150 pairs), shag, oystercatcher , red breasted merganser and rock pipit. Bird migration studies have shown that the islands are a significant station for autumn migrants.
Grey seals use the islands principally as a hauling-out place.