The Gulf of Mexico Is Sending Out an S.O.S.—a Message in a Plastic Bottle

Thanks to the Mississippi River’s trash stream, the Gulf has some of the highest concentrations of plastic in the world.

The concentrations are remarkably high, says Mark Benfield, an oceanographer at Louisiana State University who was the first to study the amount and type of plastic in the waters off the Louisiana coast. In 2015, Benfield and his team towed a net behind their boat and used water-sampling bottles to collect plastics large and small from four areas. Their research revealed concentrations as high as 18 plastic particles per cubic meter, among the highest readings in the world—as high, in fact, as in the infamous Great Pacific Garbage Patch.

These results shouldn’t be too surprising, notes Benfield, who is now studying concentrations of microplastics in the Mississippi River. Even though the delta along the coasts of Mississippi, Louisiana, and Alabama is fairly undeveloped, about 100 million people live upstream.

About 95 percent of ocean plastic comes from land (i.e., the problem isn’t only litterbug boaters), and the Mississippi River has a 2,300-mile reach. Along the way from Minnesota, it collects the discarded refuse of many of the Midwest’s most populated cities—most of it washed into the river through storm sewers. According to the Ocean Conservancy, the top five plastics found along the Gulf of Mexico’s shoreline are cigarette butts (most of which are made of a plastic called cellulose acetate), bottles, bottle caps, food wrappers, and many, many small, unrecognizable plastic shards.

Those tiny pieces may begin as rubber tires, bottles, straws, Styrofoam, laundry lint, paint, or the tiny beads in toothpaste and face scrubs—until the elements cause them to become brittle and break.

“The bigger plastics will break down into smaller pieces over time,” says Maia Patterson McGuire, a marine biologist at the University of Florida who spearheads a citizen science project called the Florida Microplastic Awareness Project. Patterson published a study last year on how plastic microfibers from polyester clothing make their way into the Gulf by way of washing machines and waterways. “The plastic itself doesn’t biodegrade and convert back into harmless elements; it just gets smaller and smaller and smaller,” she says.

That’s the dark side of plastic—it never disappears.

What has scientists most concerned are the chemical components of microplastics. Plastics themselves contain a number of chemicals, such as phthalates, suspected endocrine disruptors that upset reproduction in sea life, particularly filter feeders like oysters. Plastics also can act like sponges and absorb nasty, persistent organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), a by-product from burning fossil fuels. These harmful substances can reach concentrations in plastic up to a million times greater than their levels in the surrounding seawater. When marine animals eat the plastic particles, these toxins enter the food chain and eventually reach our own bodies.

Seabirds, turtles, and fish mistake plastic for food. Turtle hatchlings, for example, swim out to floating seaweed mats in the open ocean, where they spend the first two years of life feeding off the mat’s bounty of shrimp, fish, and, unfortunately, plastic. Ingesting it can block or harm their digestive tracts or fill their stomachs, so they eat less real food and grow more slowly.

Marine animals also get entangled in our garbage. Earlier this spring off the coast of Galveston, Texas, two critically endangered Kemp’s ridley sea turtles washed ashore wrapped in a knot of seaweed, sticks, ribbon, and deflated balloons. Theresa Morris, the Gulf program coordinator for the Turtle Island Restoration Network, says the juvenile had been dragging its own body weight in trash around its neck.

“A lot of people are sounding the alarms, and they’re using the precautionary principle, because we don’t know exactly how it will play out,” says McGuire. “But that’s why maybe we should do something about it.”

Some cities and states are already doing something about it. California is currently the only state to ban plastic bags; four of Hawaii’s five counties have done so as well. A number of local governments across the country, such as in Austin, Texas, have also banned single-use plastic bags or are at least trying to reduce their use.

Not everyone is on board, of course. The plastics industry is pushing back with a multimillion-dollar effort to develop “bag the bans” legislation. Just recently, the state of Mississippi passed a law that prevents local governments from regulating plastic bags and other plastic containers. The law goes into effect in July. Eight other states, including Florida, have also banned plastic bans.

The heart of the plastic bag war is playing out in Texas—the state with the highest number of people employed in the plastics industry. The city of Laredo and its merchants association are currently battling over whether such bans are legal, and it’s the first time the issue is being heard at the state Supreme Court level. The final decision, expected by July, will have implications for cities like Austin, which banned plastic bags in 2013, and Galveston, which hopes to follow suit.

Ultimately, the best way to curb plastic pollution is to forgo single-use plastics. At the individual level, that means switching to reusable water bottles, coffee cups, and grocery bags. Cities can also incentivize recycling and reuse. New York City is considering going after the ubiquitous plastic straw, and companies, such as Starbucks and McDonald’s, are thinking about making a shift to paper. Americans pitch 500 million plastic straws every day.

“People need to stop and ask, ‘Is there a better way?” says Coyne-Logan. After all, the real message wasn’t within that 16-year-old bottle he pulled from the Mississippi. It was the bottle itself.

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