A series of aggressive attacks on large marine animals off the coast of Montauk, New York, has spurred a scientific investigation into a powerful predator dubbed 'Sharkzilla.' The incidents, which include a humpback whale with a 24-inch bite mark and a gray seal with a 22-inch wound, prompted local shark scientist Craig O'Connell to launch a hunt on September 20, 2025.
O'Connell initially theorized that the unusual ferocity of the attacks could be linked to potential genetic mutations caused by leaking nuclear waste barrels dumped in the nearby Hudson Canyon in the late 1960s. He hypothesized that such mutations could result in a shark that is faster, stronger, and deadlier than typical predators. This theory was explored in a Discovery Channel Shark Week episode, "Sharkzilla Takes New York."
Expedition to Hudson Canyon
The search for the elusive predator led O'Connell and his team approximately 100 miles off Montauk to the Hudson Canyon, a vast underwater gorge reaching depths of up to 4,000 feet. This deep-sea environment, comparable in scale to the Grand Canyon, was believed to be a potential habitat for large sharks.
During their expedition, the team deployed a camera into the canyon's twilight zone, where they captured footage of a large great white shark and a mako shark. O'Connell and his team then entered the water to attempt to tag and collect tissue samples from the sharks, an effort described as placing themselves within striking distance. They used bait and a decoy dolphin named Hudson to attract the animals. Two mako sharks appeared, which O'Connell noted was unusual as they are typically solitary hunters. Their sudden disappearance led the team to suspect the presence of a much larger creature.
Identifying 'Sharkzilla'
As time ran out and daylight faded, the researchers deployed a "blubber blaster" designed to mimic a dead whale and attract sharks. A giant female mako shark, nearly 12 feet long, eventually charged the boat. O'Connell identified this mako as 'Sharkzilla,' believing it to be powerful enough to have inflicted the observed wounds. He successfully attached a tracking tag and collected a tissue sample before the team returned to Montauk.
Subsequent tests on the tissue sample found no evidence of radioactive mutations, disproving the team's initial alarming theory. However, the investigation did reveal that the waters in the area serve as a breeding ground for mako sharks. This discovery provided a more natural explanation for the increased predatory activity: the sharks were likely hunting to feed their developing pups.
Montauk was historically known as a prime location for encountering large sharks, but overfishing had significantly depleted their numbers. O'Connell's investigation suggested a potential return of these large predators to the area. The tagged mako's travel path indicated it was moving in the same general direction as the attacks. Ultimately, 'Sharkzilla' was identified not as a radioactive mutant, but as a large, pregnant mako shark patrolling the waters off New York.