Takuma Goto had been innocently swimming with a friend when he was set upon.

A man was left fearing for his life after a ‘sexually frustrated dolphin’ attacked him in the sea.

Last month in Fukui, Japan, one lone dolphin was reportedly responsible for attacking 21 people this summer, with some experiencing broken bones.

According to local reports, this has been happening annually since 2022.

However, one man who was victimised, has come out to share exactly what happened and its motivations may have been clear by the way it was targeting swimmers.

Takuma Goto had been innocently swimming with a friend when he was set upon.

As dolphin attacks on humans are pretty rare, Takuma wasn’t worried when he was out at sea.

However, that all changed when his friend was suddenly barraged by the dolphin.

Takuma quickly turned to help his friend as soon as he heard his cries, but the creature then set his sights on him instead.

He told The Telegraph: “I knew it was not a shark, but it came straight at me.

“It attacked me and bit me.

“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 rescued Takuma, and he managed to get away from the dolphin and wash his wounds with water on the beach.

He shared: “The insides of my finger were popping out.”

He was treated for his injury to his index finger, which received five stitches, and was also left with bite to his left wrist and forearm - as well as his right hand and upper arm.

Experts have come out to share that they believe the male dolphin may have been lonely or sexually frustrated.

The Indo-Pacific bottlenose tends to live in pods, and forms life-long male partnerships, which includes behaviors such as biting and pressing genitals against each other.

Ryoichi Matsubara, the director of Echizen Matsushima Aquarium in Fukui, told The New York Times that the dolphin was observed trying to press his genitals against people in 2022 and 2023.

This may show that he is attempting to make friends.

However, Takuma has said that he never wants to go out there again after the attack.

Other researchers have suggested that it has the desire to mate, with Simon Allen, a principal investigator at the Shark Bay Dolphin Research project in Western Australia, telling BBC News: "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.

He added: “Since they are such powerful animals, this can lead to serious injury in humans."

Because of this, Fukui authorities have discouraged people from interacting with the dolphin and have put up signs and fliers to warn beachgoers.

They also introduced lifeguard patrols and are now limiting the swimming hours on certain beaches, according to the Times.

Authorities further installed underwater acoustic devices, which emit high-frequency noises to deter dolphins from entering the beach.