RUMSON —  Bull shark sightings in the Navesink River are being checked out by the New Jersey Department of Environmental Protection.

Rumson police said the sharks were reported on Thursday in the area of Navesink Avenue.

Police chief Scott Paterson told ABC 7 Eyewitness News that nurse sharks and a beluga whale have made their way into the Navesink because of the river's warm water. He said the Division of Fish & Game, which is under the DEP, was notified.

"I wouldn't be surprised if they're in there. They've gone up rivers in New Jersey in the past," Marine Mammal Stranding Institute executive director Bob Schoelkopf told New Jersey 101.5.

Bull sharks have been spotted off Long Island this summer.

"There have been 19 shark sightings off Long Island and for a couple of years we've had reports of them pupping off Rockaway, New York," Marie Levine of the Shark Research Institute in Princeton told New Jersey 101.5.

"They go where they want to go and can be extremely aggressive," Levine said.

Area where a Bull shark was sighted in the Navesink River in Rumson (Google Street View)

It was surprising to hear about the sharks pupping off Bull sharks prefer warm water, she said.

"But the oceans are changing, the currents are changing," Levine said.

According to the Shark Research Institute based in Princeton the Bull shark is usually found close to the shore in water less than 100 feet deep around the world.

Levine described Bull sharks as "large aggressive shark with massive jaws" that move "like seasoned warriors."

"They just sort of swagger," Levine said.

They grow to a length of nearly 10 feet and are considered a danger to humans because of their "size, dentition and aggressiveness." Levine said. They are regarded as among the most dangerous tropical sharks, she said.

The search for food would bring them to the Navesink.

"It's always food," Levine said.

Levine said that sharks at the Jersey Shore and in Matawan Creek were part of the inspiration for Peter Benchley's novel and movie "Jaws."

"Since 1916, there has been much debate about the species of shark responsible for the attacks in Matawan Creek, which is less than 20 miles from the Navesink River," Levine said.

The DEP has not yet returned a message on Monday afternoon seeking an update on its investigation into the sightings.

Contact reporter Dan Alexander at Dan.Alexander@townsquaremedia.com or via Twitter @DanAlexanderNJ

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