Wikipedia lists nine Puffin Islands: two off Newfoundland (Canada), one in Iceland, one in County Kerry (Ireland), and three in the United States (one in Alaska, one in Maine, and one in Washington State), as well as the one off Anglesey in Wales. It also notes that the island of Lundy, in the Bristol Channel, may be included in the list as its name is Norse for Puffin Island – and Iceland's Puffin Island is known in Icelandic as Lundey.
Anglesey's Puffin Island is noted as a breeding ground for several species of seabirds, including guillemot, razorbill, shag and kittiwake. It's a designated Special Protection Area, particularly (according to Wikipedia) because of its colony of great cormorant.
Ironically, the puffin population of Anglesey's Puffin Island was virtually wiped out after brown rats were accidentally introduced, probably in the late 19th century. The rats now appear to have been eradicated by a programme of poisoning that began in 1998, and the puffin population is believed to have increased to around 300.
© Haydn Thompson 2021