The bright blue waters of Sarasota Bay, off Florida’s west coast, are a popular spot for boating and fishing. The bay is also the year-round home to a population of wild bottlenose dolphins, whose daily lives scientists have been studying since the 1970s. Their research has shown that generations of dolphins have learned to approach people and their boats. to eat easily. That behavior may lead to decent interactions for people on social media, but it has dire consequences for dolphins.
TO recent study Based on 28 years of data, the old saying has been confirmed: there is no such thing as a free lunch. Scientists found that dolphin mothers who interact with boaters have almost twice as many babies as females who stay away. But those babies are nine times more likely to die before reaching adulthood. This high mortality rate poses a problem for the population as a whole.
It’s not just baby dolphins that die prematurely. “The leading cause of death and mortality in Sarasota Bay is interactions associated with recreational fishing,” says Kylee DiMaggio, a marine biologist who led the study for the Chicago Zoological Society, which runs the Sarasota Dolphin Research Program. since 1989.
In the United States, feeding dolphins is illegal under the Marine Mammal Protection Act of 1972, but it still occurs frequently. “Even though we don’t mean to, just by our presence, we are conditioning animals to be closer to humans,” DiMaggio says. That proximity increases the risk of a dolphin being struck by a boat, entangled in fishing line or caught on a baited hook.
Dolphins are intelligent and social animals, and sniffling has incentives. Obtaining fish from people instead of hunting them could allow female dolphins to save time and energy that could be spent on reproduction. It makes sense that dolphins that catch bait, catch fish from a fisherman’s line, and approach boats in search of food might have more babies.
However, studies of other species around the world, such as green sea turtles in the Bahamas, show that animals that become dependent on human donations stop foraging. This is true for Sarasota Bay dolphins, and it is a preference they convey. DiMaggio says dolphins from one lineage have been approaching boats for four generations. That behavior is even more dangerous for younger ones: Young dolphins can be killed by boats or fishing gear while trying to stay close to their mothers.
For these dolphin mothers, losing multiple babies in quick succession is likely to cause emotional distress, DiMaggio says. Over time, this pressure on female dolphins and the death of so many calves could cause the population to decline.
“How we affect the lives of these animals in urban environments like Sarasota is really complicated,” says Andrew Read, a marine biologist at Duke University in North Carolina who studies the effects of human activities on animal populations. sailors and did not participate. in the study. He says dolphins in urban environments are even more likely to interact with people when their prey is scarce, such as during toxic red tides.
We can’t stop dolphins from interacting with humans, DiMaggio says. But we can teach people to enjoy wild animals from a safe distance.
And for the love of God, stop giving them food.
This article first appeared in the same magazine and is republished here with permission.