Scientists Explain Why 'Harmless' Sharks Devoured Swimmer in Chilling World First

A species of shark never before documented killing humans has now done so, devouring a swimmer in a chilling first.

On 21 April 2025, a 40-year-old tourist was snorkeling in the Mediterranean more than 100 meters off the coastline of Hadera, Israel, using a GoPro to film a group of dusky sharks (Carcharhinus obscurus) when the incident occurred.

Scientists believe the attack began when a curious shark took an exploratory bite at the GoPro and missed. Instead, the shark accidentally bit the man holding the camera; the blood and panic that ensued likely triggered a feeding frenzy among the congregating sharks.

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"Witnesses heard him shouting: 'Help…they're biting me' before he disappeared from sight as the water turned red and some dorsal and caudal fins appeared on the surface," write marine biologists Eric Clua of Paris Science and Letters Research University and Kristian Parton of the University of Exeter in the UK in a report of the incident.

"The day after, searches at sea recovered human remains (in very small quantities) that allowed the forensic confirmation of the victim's identity, but also led to the conclusion that he had been devoured by 'several' sharks during this incident."

Dusky sharks are known for their lack of aggression towards humans, making them a safe target for ecotourism activities where people can feed and interact with a fascinating marine predator.

Hadera is a popular spot to see them; the nearby desalination plant pumps warm water into the area, attracting large numbers of dusky sharks.

This frequent interaction with humans and the unnatural shark behaviors this interaction encourages, Clua and Parton believe, could be a major contributor to the fatal encounter.

"Artificial provisioning in the area has resulted in habituation with behaviors including begging, potentially resulting in a bold shark displaying a first reflex/clumsiness bite targeting the camera held by the snorkeler, unintentionally wounding him," they write in their paper.

"The sound and olfactory stimuli have likely triggered a feeding frenzy, leading to multiple sharks engaging in predation bites. In this case study, extreme competition between individuals has probably overridden the non-instinctive prey nature of the human victim."

Ecotourism can be highly beneficial to both local economies and ecosystems, providing a disincentive to shark fishing and a motive to protect their habitats. The best path forward, the scientists say, would be to ban the feeding of sharks in the region to eliminate begging behavior and maintain a healthier distance between the sharks and the humans who come to admire them.

"The worst solution," they write, "would be to unselectively eliminate all sharks present in this area in the form of a cull, since the responsibility for this specific incident lies essentially with humans."

The report has been published in Ethology.