A dolphin
Media playback is unsupported on your device

More dolphins swimming around Scotland

28 May 2015 Last updated at 08:15 BST

A new project is trying to find out why the number of dolphins swimming off the coast of Scotland is going up and up.

Marine researchers are trying to find out why a breed called the Common dolphin is thriving in the area.

Experts say the number of them swimming off the coast of Scotland has increased every year since 2001.

Kerry Froud from the Hebridean Whale and Dolphin Trust said: "This could be to do with climate change, we're not sure."

"Every decade the sea surface temperature up here in Scotland has been increasing."

"By continuing this monitoring, we'll be able to get a good understanding of what is actually out there," she said.