The vast majority of debris in the ocean — about 75 percent of it — is made of plastic. It can consist of anything from plastic bottles to packaging materials, but whatever form it takes, it doesn't go away easily.
While plastic may break down into smaller and smaller pieces, some as small as grains of sand, these pieces are never truly biodegradable. The plastic bits, some small enough that they're called microplastics, threaten marine life like fish and birds, explains Richard Thompson, a professor of marine biology at Plymouth University in the U.K.
If you stand in front of Almena and Sidney Poray's house in Baton Rouge, La., and look straight down the street, past the other houses and the shade trees, you see more than a dozen plumes of exhaust in various hues of gray and white.
"That's something you see every day, the same thing if not more," says Almena Poray. "Sometimes it's a darker gray; sometimes it's a black smoke coming out."