Researchers have urged people to help their project by finding tags which have fallen off marine wildlife.
Jersey Marine Resources (JMR) has attached small tracking devices to sharks and rays to gather data which will help the team to understand their movement patterns.
Over two days JMR attached 20 tags to tope sharks which are designed to detach from the animal after four weeks and float to the surface.
The team has promised £50 to anyone who finds and returns a tag to them.