Fish have favourite colours and dolphins hate high pitched noises. In an effort to save rapidly dwindling global fish stocks, scientists are trying to figure out how to attract the right fish into nets, and keep protected species away. On the southern coast of England, we meet the man who’s designed a hi-frequency gadget which warns dolphins to stay out of fishing nets. In Denmark, scientists show us how LED lights are able to show fish you don’t want the exit from the net. And in Oxford we hear from the researchers using satellite technology to help the Thai government stop criminals from plundering the oceans. Presenter: Myra Anubi Reporter: Rumella Dasgupta Image: The dolphin pinger