Daily SumUp

A lonely dolphin acting out of sexual frustration is believed to be the culprit behind a spate of attacks on swimmers in Japan this summer.

Since July this year, 18 people have been hurt in dolphin attacks near the seaside town of Mihama, with some requiring dozens of stitches.

Posters warning beachgoers of the menace feature an open-mouthed dolphin baring razor-like teeth. It says that the mammals “are known to be dangerous to humans” and to get out of the water if they are seen nearby.

Stressed by crowds of bathers

Wild dolphins rarely attack humans but have been known to bite or pull people underwater if they feel threatened or harassed.

This was reportedly the case when one man was killed in 1994 in Sao Sebastiao, Brazil, after an initially friendly dolphin called Tião reportedly became stressed by the attention of crowds of bathers who wanted to play with or even torment him.

Like Tião, Japan’s problematic mammal is believed to be a solitary male bottlenose dolphin, who may also be responsible for injuring swimmers in 2022 and 2023, and trying to press his genitals against them.

Putu Mustika, a lecturer and marine researcher at James Cook University in Australia, told The New York Times that dolphins can inadvertently harm humans by dint of their sheer strength when acting out mating behaviours.

“Dolphins, when they are mating, can be very wild,” she said, adding that the act of lunging on top of a human could be seen as a sexual act and a sign that the dolphin was “horny, lonely”.

This dolphin could also be naturally aggressive or aggravated by humans trying to touch it, she said.