大象传媒

Mike Dilger heads off on a boat trip out into Cardigan Bay to see bottlenose dolphins. Steve Roberts is the skipper and a dolphin researcher. The most ethical way to watch dolphins is to not to change course when you spot them: slow your boat and let them come to you. The dolphins do some spectacular leaps. Cardigan Bay has plenty of food for the dolphins; their habitat hasn't been destroyed by industrial development or big towns; the water is clean and they are largely left alone. The carcass of a harbour porpoise is discovered floating in the bay. It has probably been killed by a bottlenose dolphin, since its ribs have been broken. A huge proportion of the harbour porpoises found dead in Cardigan Bay are bottlenose dolphin kills. In Scotland this behaviour is said to be the bottlenoses practicing for infanticide, as they kill young dolphins much as lions kill the cubs of another male. In Cardigan Bay the theory is that bottlenoses and harbour porpoises compete for food. Some bottlenoses bow-ride on the way back to shore, and the scientists take identification photos of the dolphins.