COUNTRYSIDE COUNCIL FOR WALES
SITE OF SPECIAL SCIENTIFIC INTEREST: CITATION
ANGLESEY PUFFIN ISLAND
National Grid Reference: SH650820
Site Area: 31.6 ha
This Carboniferous limestone island lying less than a kilometre off the eastern tip of Anglesey is principally of interest for its nesting seabirds breeding both on its sea-cliffs and open grassland areas. The seabirds involved include the three auks, puffins, guillemots and razorbills, together with cormorant, shag, fulmar and gulls namely: kittiwakes, herring gull, greater black-backed gull and lesser black-backed gull. The island supports more than 1% of the breeding Great Britain population of cormorants. The breeding puffin population, which formerly numbered several thousand pairs, has declined significantly to currently number less than a hundred pairs. However, old records suggest substantial population fluctuations in the past. A large gullery dominated by herring gull is present.
The vegetation reflects in part introductions by man particularly of alexanders Smyrnium olusatrum and in part the low grazing pressure following myxomatosis allowing the spread of elder Sambucus nigra scrub across the island in dense stands. Nettles Urtica dioica, U. urens, hemlock Conicum maculatum, and thistles Cirsium vulgare, C. arvense are also widespread. The open Festuca rubra grasslands have diminished in extent recently. The sea-cliffs support a typical maritime flora including sea spleenwort Asplenium marinum.
The island is used as a hauling out ground by grey seals. The rare spider, Meta bourneti, known from only five British locations, has been recorded.