Orcas and great white sharks—the top two predators of the seas— could soon be coming face to face off Cape Cod.

While great white sharks are often seen off the Massachusetts coast, the area is not typically thought of as orca territory. However, earlier this week, fisherman Jerry Leeman spotted an orca swimming 40 miles east of Nantucket, Massachusetts.

Leeman managed to capture a video of the rare sighting. In the footage, an orca, also known as a killer whale, can be seen swimming alongside his fishing boat.

"There's literally a fricking killer whale beside the boat. You don't see this every day, folks," Leeman can be heard saying.

Leeman also posted several photos of his encounter with the orca on his Facebook page.

The orca was roughly 20 feet long, Leeman told the Boston Globe. It followed the fishing boat for about half an hour, staying close to the surface of the water.

"He came alongside the boat and was kind of just checking us out. It got alongside the boat about 15 feet and was kind of just easing along with us as we were towing. Then he just kind of went off on his own," he told the Globe.

The rare orca sighting comes at the same time as great white sharks generally make their way back to the area for the summer months—meaning the two predators are about to be in the same waters.

While great white sharks are infamous for being top predators, orcas are known to hunt and feast upon them. Other than humans, killer whales are the only predators that are a threat to them.

One great white shark—a female known as Andromache, measuring 10 foot 8 inches— is already there.

According to a shark tracker operated by research organization OCEARCH, Andromache is currently close to the shores of Martha's Vineyard— close to where Leeman spotted the orca. OCEARCH tags great white sharks in order to track their movements and better understand their behavior.

Great white sharks typically spend the winters in the south, then migrate along the East Coast to Canada. The sharks generally travel to the waters off North Carolina to mate, and then will head north during the spring and summer. They stop in the waters off Cape Cod to feed on seals, which are abundant there.

However, with the appearance of killer whales in the area, that could change.

Bob Hueter, chief scientist at OCEARCH told Newsweek that when these two predators come face to face "there can be conflict."

"Orcas have been seen harassing white sharks and even killing them at times," he said.

The majority of great white sharks tagged by the organization will not have arrived in Cape Cod just yet, however there are a few exceptions, he added.

"If the orca sticks around or others appear this summer, there could be some effects on the white sharks that normally feed on seals there. The two species could be in competition with each other for the gray seals of the Cape," Hueter said.

"As a matter of perspective -- it's gratifying to see orcas, white sharks, seals, turtles, fish and other marine creatures rebounding off the U.S. Atlantic coast. This is a result of dedicated efforts in marine conservation and fisheries management over the past 30-50 years. All of these efforts are paying off and we finally have a hopeful story in ocean health and conservation."

Running Away From Orcas

A 2019 study conducted by researchers at Monterey Bay Aquarium found that whenever killer whales were observed in an area, great white sharks fled quickly and didn't return for months.

Two orcas off the coast of South Africa have made headlines over the years because of their particular taste for great white sharks.

In January, David Hurwitz of whale watching group Simon's Boat Company in South Africa told Newsweek that these killer whales "literally tear" great white sharks apart to get to their livers.

Shark numbers in False Bay—where the shark-eating killer whales were observed —have fallen dramatically since the whales turned their attention to larger prey.

Before 2017, hundreds would visit the bay every year. In 2021, there were just a handful of sightings.

A recent sighting of an orca off the coast of Cape Cod, Massachusetts, where great white sharks are known to swim, has led to the possibility that those waters will be populated by two apex predators this summer. File photos of a killer whale (L) and a great white shark (R). iStock / Getty Images

Update 05/23/22 at 3:12 a.m. ET: This article has been updated to include comments from Bob Hueter.