Conditioning dolphins to humans is an effective way for people to encounter a wild cetacean up close, but it’s not so good for the dolphins, according to new research. Drawing on more than 45 years-worth of data from Sarasota Bay in Florida, biologists have found that bottlenose dolphins conditioned with offerings of food are more likely to be injured in human interactions – boat collisions, for example, or entanglement with fishing gear – compared with unconditioned animals.

Fredrik Christiansen of Australia’s Murdoch University said: “I cannot see any benefits from the animals’ perspective in being provisioned, apart from short-term energetic gains. However these are not likely to be substantial enough, or even needed, to enhance survival and/or reproduction.” The proportion of conditioned dolphins in Sarasota Bay has nearly tripled in the last decade, and Christiansen says the time has come to stop to the handouts. “There are laws forbidding food provisioning, but some people still carry out these activities, meaning enforcement is needed,” he said.