Reported sightings of leatherback turtles are increasing off Wales, with the reptiles thought to be drawn by high numbers of jellyfish.
Three sightings have been reported in recent days, in Laugharne, Carmarthenshire, north Pembrokeshire and Anglesey.
Dr Peter Richardson, of the Marine Conservation Society (MCS), said Wales’ waters were currently “turtle heaven”.
The turtles nest in the Caribbean before travelling to UK waters to feed.
Dr Richardson said there had been high numbers of jellyfish – the food source of the leatherback – reported in the Irish Sea this year.
He added: “The waters around Wales are absolutely perfect at the moment for turtles – turtle heaven.”
“What we have seen in the last few weeks is a sudden increase in the number of leatherbacks reported off the coast of the UK, mostly the south west, but in the last few days we have had three reports of leatherbacks off Wales.”
Describing the leatherback as a “spectacular animal,” he added: “Wales boasts the largest leatherback ever recorded anywhere on the planet.
“In 1988, a dead one washed up at Harlech… and it measured just under 3m (10ft), nose to tail, and weighed just under a tonne.”
In 2002 and 2005 there were about 70 sightings of leatherback turtles around the British coast, but since 2007 there have been 20 or fewer reported annually, according to the MCS.