However, it was dismissive of the threat posed by disturbance, arguing that dolphins like to bow-ride and, anyway, can go anywhere in the sea to escape persecution. Here I disagree. Dolphins stay in certain areas, even if only temporarily, because there are things there that they need, perhaps warmer water, favouring young calves, but most likely abundant or highly nutritious prey. If they are forced out, such harassment will not kill them outright but might mean that they have lower energy stores, making them more vulnerable to disease, less able to survive periods when food is not plentiful and less able to reproduce. These are slower and less agile and the nicks and scars on the backs and dorsal fins of live dolphins show that they are occasionally struck by boats.
Dolphins are creatures of the surface.
Every few minutes they must come up to breathe. Porpoises and dolphins may also be physiologically stressed by human noise and continual boat attention. If they come to you, fine. With so many threats to UK dolphins, sensible precautionary protective measures need to come into play swiftly. These include acting to control cetacean-deadly fishing activities, controlling marine pollution and reducing disturbance.