A discarded DVD case is offering a brutal example of the effects our trash continues to have on marine wildlife. A young sei whale—a member of an endangered species—was found in a Chesapeake Bay tributary, seeming confused.

Within days, it was found dead: It had been unable to eat after swallowing a sharp piece of a DVD case, which ripped its stomach. Already weak, it was also wounded by a collision with a ship, the National Geographic reports.

"It was a very long and painful decline," says a researcher, noting that the whale probably ingested the case during surface feeding. The incident is not an isolated one.

Some 56% of cetacean species have been found to have consumed debris, a study last year found, and scientists offer all kinds of disturbing stories. One describes a dead sperm whale with 400 pounds of debris in its belly.

A dead gray whale had 20 plastic bags, surgical gloves, towels, a golf ball, and even a pair of sweatpants inside it. Seabirds and sea turtles are among other animals suffering.

"We often find cigarette lighters, bucket handles, toothbrushes, syringes, toy soldiers—anything made out of plastic," a researcher told the Los Angeles Times in 2006. Some 80% of ocean litter comes from land, the Natural Resources Defense Council notes.

(Two easy ways to help? Avoiding disposable plastics and improving our recycling habits.)

This article originally appeared on Newser: Whale's Cause of Death: Swallowed DVD Case

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