Project monitors Risso's dolphins around Bardsey Island
Work has started to monitor a unique species of dolphin off the Gwynedd coast.
Natural Resources Wales (NRW) is working with the Whale and Dolphin Conservation on a long-term study of the Risso's dolphin around Bardsey Island.
It is one of only a few sites around the UK where the dolphins can be seen close to land.
NRW said the two week monitoring programme would provide "valuable information" about the dolphins' feeding habits and social interaction.