Knowledge is power
As an island nation, we are surrounded by rich seas, where some of the most remarkable marine mammals live and feed. But there is one that most of us know very little about. It is similar to the dolphin, but a lot smaller and much harder to see. It's the harbour porpoise. True to its name, the harbour porpoise lives close to the coast and the Isle of Mull in Scotland is one of the best places to see them. The Hebridean Whale and Dolphin Trust in Tobermory is trying to find out everything they can about harbour porpoises. Around the west of Scotland, the research team thinks there are around 12,000 animals, but globally in certain populations they seem to be under threat. The animals can get caught in fishing nets that are moored to the seabed, and they can be affected by noise pollution. The porpoises use sound in their everyday lives: to find food, navigate and also to communicate with others, so making the marine environment more noisy, makes it more difficult for animals like these to go about their daily lives. The team has an underwater microphone which they tow behind their boat in an effort to listen to the calls made by the harbour porpoises. The harbour porpoise calls at a very specific frequency which the computer can distinguish. Dolphins and porpoises echolocate in the same way that bats do, by sending out calls and listening for the returning signals which helps them both navigate and find food.