Japan: Experts suspect lonely dolphin behind rise in attacks

Residents of a seaside city in Japan have been harshly advised to stay away from dolphins, even though they are depicted as pleasant creatures in tale books.

The reminder in the city of Mihama, Fukui prefecture, gets more forbidding:” They you lick you with their sharp gums and cause you to burn, or … drag you into the water, which could be life-threatening”.

Dolphin assaults in Fukui have increased for the second year in a row, which marine experts attribute to a single, sexually frustrated bottlenose dolphin.

The beach watch reports that 18 people have been hurt at beaches in the province this summer, including an elementary school student whose hand required at least 20 needles.

At least six people were injured last year, including a swimmer left with broken ribs, and one in 2022.

The dorsal fin of a whale seen biting a man’s hands at a beachfront in Tsuruga, a switch area next to Mihama, matched those of a 2.5m much dolphin that was seen off the coast of Fukui previous year, according to Tadamichi Morisaka, a professor of cetology at Japan’s Mie University.

The dorsal fin is like a dolphin’s fingerprint, as each has distinctive notches, ridges and pigmentation.

It is reasonable to assume that it is the same person because the wounds on the tail fin are similar to those on dolphins seen off the coast last year, and it’s unusual for dolphins, which normally move in groups, to be alone for such a long time, Prof Morisaka said.

He added that male bottlenose dolphins communicate by “play-biting each other.” ” They are not trying to injure people, but are using the dolphins ‘ way of communication with people”, he said.

Other people have suggested a number of theories as to why the same thing might be responsible for these attacks, including a desire for sex.

” Bottlenose dolphins are very social animals, and this sociality can be expressed in very physical ways,” said Dr. Simon Allen, a biologist and principal investigator with the Shark Bay Dolphin Research project.

” The dolphin may injure the people it interacts with, just as in humans and other social animals. Hormonal fluctuations, sexual frustration, or the desire to dominate may cause this.” Since they are such powerful animals, this can lead to serious injury in humans”, he said.

The dolphin may have sought alternative companionship and been “obstracized from its own community,” according to Dr. Allen.

The dolphin may be using its own defense, according to Dr. Matthias Hoffmann-Kuhnt, a marine mammal expert at the National University of Singapore.

According to him, when people get too close to these dolphins and are unsure of how to behave themselves, this is more frequently a defensive behavior, he said, referring to reports of people trying to ride the animals or slamming their fingers into their blowholes.

He claimed that it is no wonder that animals then become aggressive or at least guarded against people in the water.

It might also be that the dolphin had a negative encounter with a human before and now projects that relationship onto other people it runs into, according to Dr. Hoffmann-Kuhnt.

” They have good memory, similar to elephant who will remember who mistreated them before”, he said.

Dolphin attacks can be fatal. Two male swimmers who attempted to ride a dolphin in Brazil in 1994 were attacked, killing one and injuring the other. The dolphin, nicknamed Tião, was believed to have injured at least 22 people before that.

Chika Nakayama provided additional reporting in Tokyo.