New Video: Great White Shark Leaps After Seal in Cape Cod

The dramatic behavior, usually observed off South Africa, is rare for the eastern U.S., according to shark experts.

Watch a great white shark attempt to catch a grey seal off the coast of Cape Cod, Massachuestts.

This one's a nail-biter: A seal desperately twists and turns to escape the toothy predator leaping out of the water in a quest for its next meal.

Researchers caught this macabre ballet between a great white shark and a grey seal on Monday, and video of the chase has since gone viral. Most such instances are captured on camera in South Africa. But this time, the drama played out off of Cape Cod, Massachusetts.

The seal in the video looked like it was coming closer to shore when it encountered the predator, says Greg Skomal, a shark expert with the Massachusetts Division of Marine Fisheries in New Bedford. The roughly 12-foot (4-meter) white shark researchers have nicknamed "Lumpy" was unaware of the seal until the two were fairly close to each other, he says.

That's because the water around Cape Cod is murky, and so sharks need to get pretty close to their prey in order to get a visual lock on them.

Once the shark realized potential prey was approaching, "the shark just charged the seal," says Skomal, who filmed the encounter. "The seal suddenly saw the shark coming at it and launched itself out of the water."

The chase occurred in about 6 to 8 feet (2 to 2.5 meters) of water. And because the water was so shallow, the shark's speed catapulted it out of the ocean, Skomal says.

Rare Behavior

Though leaping or breaching behavior is most often observed around South Africa, it probably happens throughout the great white shark's range, says John Carlson, a research biologist specializing in sharks with the National Marine Fisheries Service in Panama City, Florida. The sharks are found throughout the world in temperate coastal waters.  

People have observed white sharks off California leaping, but it's usually when the sharks go after seal decoys researchers tow behind their boats, says Skomal. (Read about why white sharks are thriving in U.S. waters.)

Even so the Cape Cod incident is fairly rare, Skomal says. Seals in that area tend to hug the bottom when they swim, which means the sharks aren't charging the surface to go after them.

However, when sharks in the lamnid group—which includes great whites, mako, and salmon sharks—do spot prey at the water's surface, they're uniquely built to go after them, says Carlson.

"I have a colleague that works on salmon sharks [in Alaska] and he's seen them breaching out of the water with salmon in their mouths," Carlson says.

Built For Speed

Lamnid sharks have a network of capillaries, or tiny blood vessels, that warm their muscles above the ambient temperature of the seawater. That allows them to put on bursts of speed for a short while. This ability, combined with a powerful, streamlined tail, enables these sharks to leap out of the water after prey, Carlson explains.

Tuna and billfishes, some of the fastest fish in the ocean, also have these adaptations.

Carlson wouldn't be surprised to see sharks leaping after seabirds resting on the water. "But it's probably mostly seen when [the sharks] are feeding on seals."

Alas, despite the Cape Cod white shark's efforts, its prey got away—leaving a hungry shark roaming the Massachusetts coast for the next unwary seal.

Follow Jane J. Lee on Twitter.