A crew of shark specialists traveled to a secluded island off the coast of Nova Scotia, hoping to track down a little-understood group of massive great white sharks that can reach lengths of up to 20 feet.
At the center of the mission was ‘Big Rose,’ a rarely seen female estimated to weigh three tons and thought to be among the largest great whites ever recorded in the North Atlantic.
Shark researcher Dr Neil Hammerschlag first encountered the enormous predator last year. He returned for Discovery’s Shark Week special Invasion of the Mega Sharks, airing Sunday at 10pm ET, with one goal in mind: to find Big Rose again and fit her with a tag.
The expedition comes amid reports that great white sightings between Cape Cod and Nova Scotia have climbed by 1,000 percent over the past decade, with scientists noting an increasing number of what Hammerschlag called ‘very large, massive great whites.’
Their search led them to Mud Island, the remote location where Big Rose was last spotted and a developing hotspot for sharks far bigger than the eight- to 10-foot great whites more commonly documented around North America.
To bring the animals within range, the researchers lowered a cage alongside their vessel and placed bait in the water, aiming to identify, measure and tag any sharks that approached.
It did not take long for huge silhouettes to rise from the deep. The team encountered several large sharks, including three over 14 feet long and a 16-foot female they nicknamed Sweetheart.
Still, as night began to fall, the 20-foot giant that had drawn them hundreds of miles into the Atlantic remained nowhere to be seen.

A team of shark experts ventured to a remote island off Nova Scotia in search of a mysterious population of enormous great whites measuring up to 20 feet long

Their ultimate target was ‘Big Rose,’ an elusive three-ton female believed to be one of the largest great white sharks ever encountered in the North Atlantic. The sharked earned the name for a rose-like pattern on its fin
Hammerschlag climbed into a tiny inflatable boat and maneuvered dangerously close to the circling predators, armed with an air-powered veterinary gun designed to fire tracking tags into their sides.
Surrounded by great whites, he successfully tagged four of the animals, allowing the team to monitor their movements around the island.
The following morning, the trackers delivered an unexpected clue: All four sharks had moved to the opposite side of Mud Island.
Suspecting Big Rose might have followed them, the researchers packed up their equipment and raced to the new location.
But when they arrived, the ocean appeared strangely empty.
Hours passed without a single fin breaking the surface, raising fears that something was preventing the sharks from approaching the boat.
Underwater cameras eventually revealed the truth. Shadowy predators were circling far beneath the vessel, refusing to rise from the murky depths.
To reach them, the team deployed a custom lightweight cage capable of descending much farther than its original equipment.

Researchers dropped a 50-pound slab of bluefin tuna into the water and waited.
Shark Week expert and attack survivor Paul de Gelder climbed inside and dropped 50 feet to the ocean floor for what the program described as the first bottom-cage dive conducted at the island.
Through the gloom, a 13-foot great white suddenly appeared, confirming that the predators had not left; they were simply staying deep.
Then an even larger silhouette materialized beyond the cage.
Poor visibility made it impossible for de Gelder to identify the animal, and with his air supply running low, he was forced to abandon the dive and return to the surface.
The team was now convinced a monster was hiding below, but it needed to draw the shark into daylight to determine whether it was Big Rose.
Researchers dropped a 50-pound slab of bluefin tuna into the water and waited.
Moments later, a gigantic great white emerged from the depths and closed in on the boat, wrapping its jaws around the bait and dragging it through the water.
As the shark passed the cage, the team spotted the distinctive rose-shaped marking on her dorsal fin that had inspired her name. It was Big Rose.

Moments later, a gigantic great white emerged from the depths and closed in on the boat, wrapping its jaws around the bait and dragging it through the water
The researchers erupted in celebration as the massive shark circled the vessel. Their measurements indicated that she stretched approximately 20 feet from nose to tail, measured six feet across and weighed roughly three tons.
Experts estimated that Big Rose was more than 50 years old, making her not only exceptionally large but also one of the oldest predators patrolling the region.
The team dropped a second piece of tuna into the ocean, hoping to tempt her within range of Hammerschlag’s tagging equipment.

Experts estimated that Big Rose was more than 50 years old, making her not only exceptionally large but also one of the oldest predators patrolling the region
But Big Rose disappeared back into the depths and never returned, denying the researchers the opportunity to track where she traveled next.
Her reappearance at Mud Island nevertheless offered an important clue. Experts said her repeated visits suggested the remote location held ecological significance for great white sharks.
Over the following month, Hammerschlag tagged three additional large sharks as the team documented 109 great whites around the island, including 25 that appeared on multiple occasions.
Tracking data later showed Sweetheart traveling down the entire US Eastern Seaboard, passing Florida and eventually reaching Louisiana.
Although Big Rose escaped without a tag, the researchers said her immense width suggested that she had returned to the area to give birth.
If their suspicions are correct, an undiscovered great white birthing ground may be hidden somewhere nearby, meaning the hunt for Big Rose has uncovered an even greater mystery beneath the North Atlantic.