The UK is home to most of Europe's seals, but their numbers are dropping and scientists are trying to find out why.
There are two different types that live here, grey seals and harbour seals, and most of them can be found in the Orkney Islands in the north of Scotland.
Over the last decade there's been a big drop in the number of harbour seals and researchers are tagging them to track where they're swimming to.
They hope it will give clues as to why so many are disappearing and help them find a way to stop the decline.
Leah's been to find out more...