A deep-sea diver says that he made what he believes to be a startling discovery when he made his record-breaking dive in the Pacific Ocean last month.

Texas diver Victor Vescovo went 10,928 meters down into the Challenger Deep in the Mariana Trench. The groundbreaking mission was filmed as part of an upcoming Discovery Channel documentary series that will chronicle Vescovo's trips to the furthest parts of the world's waters - the Atlantic Ocean, the Southern Ocean, the Indian Ocean, the Pacific Ocean and the Arctic Ocean. He has done all except the Arctic plunge, which is set for the fall.

Vescovo says that while he was down 7 miles below the surface, he believes that found a plastic bag or at least an item that is man-made.

Plastic waste in the ocean has become an increasing environmental concern, according to most environmentalists.

“Plastic is a pervasive problem throughout the world and we’re finding it, not only at the deepest part of the ocean bottom, but at the highest point up on Mount Everest,” says New Jersey Sierra Club director Jeff Tittel.

Towns across the country have been trying to limit the amount of disposable plastic its residents are using. Restaurants have discontinued the use of plastic drinking straws and several towns have banned the use of single-use plastic shopping bags.

“What we're finding in New Jersey and other places around the world is that microplastics are getting in our drinking water. There's a study by Rutgers that showed that on the Raritan River and Passaic River, above water supply intakes, that these small particles called microplastics were found at a very high rate,” says Tittel.

Tittel says that towns should start to phase out the use of such plastics, followed by an overall ban.

New Jersey lawmakers tried to implement a statewide 5-cent fee on plastic carry-out bags last year, but Gov. Phil Murphy vetoed the bill.