The Tsuruga Coast Guard Office said that the incidents, which began in 2022, have escalated rapidly. Among the injured was an elementary school student whose finger required extensive stitching and a month to heal.
Experts suggest that a single Indo-Pacific bottlenose dolphin may be responsible for the attacks. Tadamichi Morisaka, a professor of cetology at Mie University, identified the suspect as a 2.5-meter-long dolphin previously observed in the area.
"The dolphin may be coming to the beach in search of human interaction," Morisaka said, warning that such interactions can lead to aggressive behavior.
In response to the incidents, some beaches have installed ultrasonic deterrent devices. Local officials have advised swimmers to exit the water immediately upon dolphin sightings, emphasizing that capture of the animal is currently not planned due to government regulations.