Plastic Oceans

Plastic has only been produced commercially since World War II. When I was a sixth grader in Monterey, thirty years later, a short walk on the beach showed there was already a lot of plastic trash floating in the ocean. Still, the seawrack of styrofoam cooler lids, soda bottles, and fishing bobbers didn't seem to be much more than ugly. And we didn't worry about it much, except to be careful with six-pack rings since they could strangle birds.

The scale and seriousness of the problem is now more clear. Greenpeace recently released a report, "Plastic Debris in the World’s Oceans," that synthesizes the results of a number of studies published between 1990 and 2005. The oceans have become what Charles Moore of the Algalita Marine Research Foundation calls the "world's largest landfill." They are packed with plastic bottles, shopping bags, cigarette butts, syringes, lighters, fishing gear, and more. In what has come to be called "ghost fishing," abandoned nets continue to catch and kill huge quantities of fish. Meanwhile, seals, sea lions, whales, dolphins, turtles, birds, and other animals get entangled in floating plastic ropes, lines, bands, and nets. These are not occasional incidents. One study found that as many as 130,000 whales, dolphins, and porpoises are caught in derelict nets each year. Another found that 40,000 fur seals were killed by plastic entanglement every year in the Bering Sea.

Floating plastic is gradually broken down by sunlight and wave action into particles the size of sand grains that float in the top few fathoms of the water column and even gather in windrows on the surface. In the North Pacific Subtropical Gyre, an Africa-sized area of still winds and currents where flotsam accumulates, there is six times more granular plastic in the water than plankton. This is just one of seven similar gyres around the world. Marine animals mistake granular plastic for food, eating it in large quantities. Studies of sea turtle carcasses found that more than half had ingested significant quantities of plastic. Once ingested, plastic blocks the digestive tract, causing malnutrition and starvation. In addition, plastic fragments absorb chemicals that are not water soluble, including DDT and PCBs. These toxins disrupt hormonal functions once they are ingested, reducing the reproductive rates of many species.

Alan Weisman devotes a chapter of his powerful new book, The World Without Us, to plastic in the oceans.