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A group of fishermen are on a shark-hunting mission off the west coast of Scotland.
They are hoping to catch, tag electronically and then release as many sharks as they can.
A number of shark species are endangered, and the project will help scientists find out how many are left, and learn more about their behaviour.
Shark numbers are falling because they are often caught by accident, or used to make shark-fin soup.
A shark is tagged by a fisherman
There are thought to be 18 different species of shark living in the seas around the UK.
Each shark that's caught is injected with a microchip and the information is put onto a database.
The tagging will go on for three days. It's hoped the results of this survey will help prevent the sharks dying out.