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Sierra magazine
Message in a Bottle

Seabirds are starving with bellies full of trash. Fur seals in New Zealand poop shards of yellow and blue. The Great Pacific Garbage Patch is twice the size of Texas. Now the bad news: Plastic never goes away, and scientists are finding that it absorbs toxins with spongelike efficiency. The fix? Cut it off at the source.

By David Ferris

Part 2: The Scientist

Even as Moore was discovering the Garbage Patch, other scientists were launching inquiries into plastic's effect on the ocean. One, a tall, spare Englishman named Richard Thompson, can't forget a beach cleanup he led during his grad school days at the University of Liverpool. In September 1993 he and five other volunteers combed Poyllvaaish, a rocky shoreline on the Isle of Man, expecting to pick up a truckload or two of debris. After sending off 30 truckloads of mattresses, fishing nets, televisions, plastic bags, bottles, and shipping pallets, Thompson had to plead with the local constabulary to haul away the pile that remained. "The quantities just staggered me, really," he says.

Now 45, Thompson teaches marine ecology at the University of Plymouth in southwest England. He has become one of the world's foremost experts on ocean-borne plastics, with a particular fascination for the geriatric end of the polymer "life" cycle--the point at which nurdles and their kin decompose into smaller and potentially more dangerous forms. His sixth-floor office window looks out on the port where Charles Darwin set sail on H.M.S. Beagle. In a temperature-controlled lab across the hall, researchers feed bits of polymer to mussels. Here, too, is the Fourier transform infrared spectrometer that tells Thompson what sort of plastic he's found on the tide line.

The not-so-natural life cycle of a nurdle: from refinery to factory to store to trash to the now-synthetic sands of Hawaii's Kamilo Beach, which has been called the most plasticized beach in the world.

In an upcoming edition of the Philosophical Transactions of the Royal Society, the oldest scientific journal in the English-speaking world, Thompson spells out to the scientific community how deeply plastic has woven itself into nature's web. He solicited reports from biologists, chemists, and toxicologists who span the globe but are few enough to fit on the deck of a trawler. He learned that on Diego Garcia, an atoll in the Indian Ocean, hermit crabs live in bottle caps instead of shells. The kittiwake of northern Denmark raises its young in a cliff nest assembled mostly from drinking straws, plastic twine, and ear swabs. In a 600-foot-deep trench off the coast of Marseilles, France, troves of Evian bottles lie perfectly preserved, absent the light or oxygen to break them apart. The fur seals of Macquarie Island, far off New Zealand's southern tip, poop bits of yellow and blue.

Thompson discovered studies from the late 1960s documenting albatross eating plastic and reports over the ensuing decades of turtles chewing on shopping bags and seabirds strangled by six-pack rings. Photos of these hapless animals first awakened the public to the menace. Plastic objects kill an estimated 100,000 marine mammals and one million birds every year, including the albatross: mistaking trash for fish, it starves with a stomach full of cigarette lighters and disposable forks.

Thompson also cites a lesser-known but confounding problem that accompanies drifting plastic. Like a sailboat that hasn't been scraped, flotsam amasses an underwater ecosystem. It grows a green and gray beard of seaweed, barnacles, and mussels, with a few fish trailing along. Species have always migrated by floating on pieces of pumice or driftwood, but nothing on the scale introduced by basketballs and yogurt containers.

The modern era's explosion of floating matter--46,000 pieces of plastic per square mile of ocean, according to the U.N. Environment Program--is an invitation for marine life to invade foreign shores.

"It's making a very big impression on life on the planet," says David Barnes, an ecologist who has found barnacles barging into new habitats from the equator to the Arctic. "The world shoreline has obviously been dramatically changed just in my parents' generation."

Even as he led the scouring of Liverpool's beaches, Thompson found himself less interested in the gross chunks than in the little bits underfoot--constellations of colorful dots hardly larger than grains of sand. Later, when he got his first teaching job and squad of graduate students, he took them to the beach. "In between the pieces of rock, we were finding bright pieces of blue or red, pieces that were long or fibrous," he recalls.

With the help of the spectrometer, Thompson determined that they were specks of polypropylene, polyethylene, and polyester as small as 20 microns across, narrower in breadth than a human hair. These tiny, broken shards had once been lasagna trays or construction tarps. He called them microplastics.

The sun's ultraviolet rays make plastic brittle, and the grinding action of waves breaks it to pieces, but polymers don't vanish. They just get smaller and smaller. Since the 1930s, researchers had sampled populations of krill ten feet underwater by attaching trawls to merchant marine vessels that plied the same routes through the North Atlantic each year. Many samples had been preserved, and by studying them, Thompson concluded that between the 1960s and the 1990s, the density of microplastics had increased threefold.

Meanwhile, across the globe in the Pacific, Moore pulled similar trawls through the Garbage Patch behind the Alguita. In some areas the ratio of plastic to plankton was six to one. On an expedition last year, the Alguita's crew harvested hundreds of lantern fish, two-inch midgets that make up 90 percent of the biomass in the middle depths of the ocean. They are a staple of the tuna, swordfish, and mahimahi caught near Hawaii. Ninety percent of the tiny fry had eaten plastic--one had 84 fragments in its belly. The dissections revealed nurdles and Thompson's colorful microplastics as well as minuscule uniform bits that are a new item on the ocean's dinner plate: abrasives. More and more, plastic powder is used to scrub grime from airplane fuselages and exfoliate skin in the shower. The powders are so small that they run unimpeded from the drain to the sea.

"In parts of the ocean, a fish is more likely to consume plastic than actual food," Moore observes. Then he asks the natural question: "If these plastics are in fish, and birds and other fish are eating those fish, how far is plastic moving up the food chain?"

Thompson has an initial answer. Last year he fed microplastics to mussels and found that the microplastics jumped unaltered to the circulatory system, where they stayed for four weeks before being flushed. How else a polymer diet affects the mussel, or other sea creatures, or higher predators, is still unknown. But a provocative suggestion comes from our friends the nurdles.

Across the Pacific in Tokyo Bay, a toxicologist named Hideshige Takada took an interest in nurdles because they told him something about pollution. In ocean water, Takada noticed, nurdles and other plastics suck up toxins like sponges. They hold concentrations up to a million times greater than the surrounding water. The round pellets washed up on Tokyo's shores carrying loads of polychlorinated biphenyls (PCBs) and the insecticide DDT, even though both had been banned worldwide more than three decades earlier.

Takada realized he could use nurdles as an indicator to track the imprint of toxic chemicals on the ocean. He put out an appeal for beachcombers around the world to mail him nurdles they'd found. He got thousands, from Italy, Mozambique, Vietnam, and 14 other lands. Takada found the highest concentrations of both poisons off the coast of the United States, where the compounds were made in greatest quantity.

At the same time, Takada fed PCB-laced plastic to streaked shearwaters, a common seabird of the eastern Pacific. PCBs and DDT nestle in the fat stores of fish and mammals and accumulate in greater concentration the higher one goes in the food chain. PCBs mess with the reproduction of marine mammals, spur skin lesions and liver damage in humans, and may cause cancer, while DDT causes nerve damage and may tweak a mammal's sex hormones. Sure enough, Takada found that the plastic-gobbling shearwaters had three times more PCBs in their preen glands than shearwaters that ate just fish.

It is still unknown whether some plastics are more toxic than others, or whether a line can be drawn from tiny crumbs of plastic drifting in the Pacific to the tuna on the supermarket shelf. The U.S. government isn't alarmed, at least not yet. Holly Bamford, who heads the National Oceanic and Atmospheric Administration's marine debris program, says more studies are needed to determine whether plastic is a toxin in the food chain.

Thompson, meanwhile, anticipates years of research before science gets a clear view of what plastic is doing to the oceans, and to us. Every so often, he pulls on his Wellington boots and bright yellow oilskin coat to survey the beach at Thurlestone, on England's southern coast, and see what sort of castoffs are stranded in the wrack line. Whether it's Coke bottles entombed on the seabed or the tiny shards he finds in the sand, he knows it's all still with us, all the plastic we've ever produced.

Part 3: The Lawyer

Bottom photos, from left: Paul L. Nettles, iStockphoto/alistaircotton, iStockphoto/kgtoh, iStockphoto/FotografiaBasica, the Algalita Marine Research Foundation



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