‘Harmless’ shark species now attacking humans, stunning scientists
In this DML Report…
In April 2025, Barak Tzach, a 40-year-old father of four, was fatally attacked by sharks while snorkeling at Olga Beach in Hadera, Israel, on his way home from work. Equipped with a mask, snorkel, fins, and a GoPro camera, Tzach entered the water to photograph sharks from a distance without touching or feeding them, using the camera stick to gently push them away when they approached too closely. Footage captured his final moments as he thrashed in the water during the mauling, and his remains were recovered the next day in small quantities, indicating involvement of multiple sharks in the attack. Videos from social media showed other beach-goers, including children, standing in shallow water and observing sharks swimming around their legs shortly before the incident.
Scientists from PSL University in Paris, led by Eric Clua, identified the sharks as Dusky sharks (Carcharhinus obscurus) in a study published in Ethology, based on witness interviews and attack footage. This species, which grows up to 12 feet long and weighs 350 to 400 pounds, is a carnivore previously undocumented in human attacks and not considered traumatogenic to people. The study suggests the GoPro's slight electromagnetic signal may have initially attracted the sharks, mimicking a wounded fish, while habituation from regular human feeding in the area has led to "begging" behavior where sharks approach people expecting food rewards.
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The researchers warn that such signals could trigger a reflex bite, and given the sharks' sharp teeth, even a minor injury might cause severe bleeding, drawing more sharks through olfactory cues like blood and auditory signals from jaw snapping. They recommend local authorities ban public shark feeding and spearfishing to mitigate risks, noting that warm waters will likely keep the sharks present but potentially less aggressive without human intervention. The study emphasizes avoiding unselective culls, as human actions bear primary responsibility, marking this as the first recorded fatal attack by Dusky sharks on a human.