A 40-year-old tourist was swimming and filming about 100 meters offshore in Hadera, off the coast of Israel, in April when he suddenly found himself surrounded by a shudder of dusky sharks, a species generally considered harmless to humans.
Witness testimonies suggest that a shark reportedly pounced on his GoPro camera. Witnesses then heard him shout: “Help… they’re biting me,” before disappearing from view as the water turned red and some shark fins could be seen on the surface. By the time rescue boats were able to arrive, the water was bloody and the man was gone, local reports say.
“The following day, sea searches recovered human remains (in very small quantities) that allowed forensic confirmation of the victim’s identity, but also led to the conclusion that he had been eaten by ‘several’ sharks during this incident,” investigators wrote.
The report, published in the magazine Ethologydocuments the first known case of a dusky shark (a species with no known history of killing humans) fatally attacking a diver during a feeding frenzy.
Researchers have attributed the extremely rare attack to a combination of factors, including human error, ecological distortion and animal instinct in the midst of a feeding frenzy.
While dusky sharks are large and appear to be imposing predators, reaching up to about 10 feet (3 m) in length, they are typically shy and distrustful of people.
The sea off Hadera in Israel has attracted these sharks en masse due to the warm water coming out of the desalination plants on the coast.
Additionally, human feeding of these sharks, as well as the abundant food waste dumped in the region, has served to further attract dusky sharks, of which dozens remain each winter.
Local boat operators catering to tourists have also dumped fish scraps into these waters to keep the sharks close to customers.
These factors together have led sharks to associate humans with food and develop in them a new behavioral pattern called “begging,” the scientists explain.
Several sharks have been documented swimming directly toward divers, sometimes even brushing past them, in search of quick food.
Careful examination of images taken from the scene revealed that the sharks are likely dusky sharks based on the size and shape of their dorsal fin.
Scientists theorize that the competitive feeding environment created in these waters has led dusky sharks to exhibit frenzied feeding behavior.
Dusky sharks are attracted to the warm waters off the coast of Hadera (AFP/Getty)
“Competition for access to the food resource overrides the habitual behavior of the species, including the intrinsic and non-instinctive nature of the (human) prey,” they wrote.
“The situation likely occurred through a process of bite juxtaposition, with two distinct motivations: the first, a (probably single) reflex/clumsiness bite driven by begging for food, and the second, several predatory bites triggered by a feeding frenzy,” the researchers explain.
The solutions that could be adopted to prevent incidents of this type in the future are simpler and more effective than in the case of the classic fatal bite from a shark from a deadly species known as the tiger shark, they say.
“The central goal is to eliminate begging behavior among sharks, and this can only be achieved by establishing and enforcing a complete and total ban on all artificial feeding of sharks by the public,” the scientists write.
“Any other measure could be complementary, but certainly less relevant than this approach,” they conclude.