Swimmer attacked by ‘sexually frustrated’ dolphin in Japan says he’s ‘lucky to be alive’

Experts believe a solitary male bottlenose dolphin could be responsible for multiple attacks on swimmers in Fukui, Japan, this year.

A man says he is lucky to be alive after being attacked by a “sexually frustrated” dolphin which experts believe is responsible for terrorising a Japanese town throughout the Northern Hemisphere summer.

Takuma Goto had been swimming off the town of Tsuruga in central Japan with a friend this year when they were attacked by a lone dolphin.

Experts believe a single dolphin, which may be sexually frustrated, could be responsible for at least 15 attacks on swimmers in Fukui during the summer months, up from five incidents last summer and one in 2022.

Dolphin attacks on humans are generally considered rare, given that they do not see us as prey, which initially gave Goto a false sense of security.

He and a friend had been swimming at Crystal Beach before going about 20 metres offshore when the dolphin attacked, first targeting his friend.

Alarmed at his friend’s cries, Goto turned to see what was happening as the dolphin’s head breached the surface.

“I knew it was not a shark, but it came straight at me,” he said, adding that he did nothing to attract or antagonise the dolphin, but that it nonetheless began a sustained assault.

Japanese authorities have posted signs warning swimmers of the dangers of dolphins. Photo / Tsuruga Coast Guard Office

“It attacked me and bit me,” he said.

“It kept attacking me and I genuinely believed that I was going to die. I was most worried that I was going to be dragged under the water and further out to sea.”

A surfer eventually came to Goto’s rescue as onlookers watched in horror from the beach. Once he was ashore, he washed the bite wounds with water and was taken to a nearby hospital. “The insides of my finger were popping out,” he said.

The 23-year-old, who works in financial sales, was left with a massive gash on his left index finger, which required five stitches, as well as bite wounds to his left wrist and forearm and his right hand and upper arm.

Experts believe the lone dolphin may have been trying to communicate by biting, a common trait among male mammals.

“It appears that the multiple incidents have been committed by the same individual dolphin,” said Mari Kobayashi, head of the marine biology laboratory at Tokyo University of Agriculture.

“It is believed to be a male Indo-Pacific bottlenose and we know that males sometimes communicate by biting each other, so it may be that it is trying to do this with humans,” she said. “Also, this is a species that usually lives in groups, so it is possible it is lonely”.

Bottlenose dolphins’ sociality ‘can be expressed in very physical ways,’ says expert

Experts also believe the dolphin may be sexually frustrated following reports in other incidents that it attempted to press its genitals against its victims.

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

“Just as in humans and other social animals, hormonal fluctuations, sexual frustration or the desire to dominate might drive the dolphin to injuring the people it interacts with. Since they are such powerful animals, this can lead to serious injury in humans.”

Allen added the dolphin may have been shunned from his own community and could therefore be seeking “alternative companionship”.

Shoichi Takeuchi, of the Tsuruga Coast Guard office, said emergency medical teams had been summoned to treat people who had been attacked this year, with those who had sustained minor cuts and abrasions allowed to go home, but others requiring their wounds to be disinfected and stitched.

The authorities have since posted signs warning swimmers of the dangers, including a picture of a dolphin baring its teeth.

“If people see a dolphin off the beach, we advise them to get out of the water immediately, to keep their distance and not try to feed them,” Takeuchi said.

Goto said he is not taking any chances. “Whenever I look at the sea, I can’t help but think a dolphin might be out there. I’ll never go back.”