Great Pacific Garbage Patch and Gyres

The Great Pacific Garbage Patch is an almost formless collection of floating junk yards that stretch for hundreds of miles across the North Pacific Ocean. It's a genuine nightmare, a global problem made of plastic and other materials that are made, used, and carelessly discarded by humans and wind up as an enormous conglomeration of marine debris, often inside animals' stomachs or around their necks. Because the garbage patch is not one continuous floating mass, its size is difficult to determine with any degree of accuracy, though it could easily be twice as large as Texas. Typically, the Great Garbage Patch is discussed as having two major parts, the Eastern and Western.

It should be noted at the outset that the name, Great Pacific Garbage Patch, is not only a misnomer but a highly misleading misnomer. No continuous or semi-continuous island of trash has formed in the Pacific. Nor is the Garbage Patch a blanket of trash that can be seen with satellite imagery or aerial photographs. Nor does the marine debris typically consist of easily visible items such as plastic bottles, bags, and other litter. Small pieces of plastic are the most typical floating debris found in the Garbage Patch and most are so small they are not easily seen by the naked eye, not even from a nearby boat.

Modern society loves plastics because they’re cheap, lightweight, and seem to last forever. And that’s the problem; most plastics don’t biodegrade very easily, even in harsh conditions or even after being immersed in salt water and exposed to sunlight for six or seven decades. Individual pieces may become smaller, but that doesn’t diminish the problem, which is that those pieces are being consumed by an enormous variety of ocean organisms.

But not only are the plastics themselves the source of myriad health problems for ocean life-forms, they also are chemical sponges, soaking up lethal cocktails of PCBs, DDT, and nonylphenols (common family of biodegradation products of a widely distributed group of nonionic surfactants used in foods and drinks, pharmaceuticals, and skin-care products), all of which are oily toxins that do not dissolve in seawater. Plastics floating in the Eastern Garbage Patch have been found to contain up to one million times the level of those toxins that are floating in the water itself. When that plastic is indigested, the poisons are released, affecting the consuming animal, its progeny, and its predators. The toxins act as hormone disruptors that change reproduction rates, sex ratios, and disrupt the growth and function of male and female reproductive organs.

On a physical level, many types of ocean birds have been found to have consumed such large quantities of plastic that food digestion is disrupted and the animal dies of starvation or other related gastric disorders. Dutch scientists have used northern fulmars to monitor flotsam in the North Sea. After several decades of analyzing the stomach contents of fulmars they found that in the early 1980s, 92 percent of the fulmars they tested had ingested on average 12 pieces of plastic. But by the late 1990s, 98 percent of bird stomachs contained an average of 31 pieces plastic.

Today, the world annually produces 250 billion pounds of plastic pellets that will become ingredients in cars, cell phones, computers, toothbrushes, medical equipment, Tupperware, gallon milk jugs, tape dispensers, children’s toys, CD cases, and thousands more. Most of that material becomes trash in a matter of years. Obviously, the enormous collection of plastic found in the Northern Pacific Gyre reflects our profligate and irresponsible trash-disposal techniques.

But the problem is not limited to improper disposal. Even the act of moving goods intercontinentally contributes to the problem. At least several thousand containers (estimated at between 2,000 and 10,000) fall from or are washed off giant container ships as they cross the oceans annually. Many of those containers hold materials that float, like plastic bath toys, or bags. In 1992, a container fell from a ship crossing the Pacific from Asia, releasing 28,800 toy ducks, frogs, turtles and beavers that floated across the Northern Pacific, washing onshore from Alaska to Japan; many made it even across the North Pole and into the North Atlantic. Also in 1992, five containers of Nike athletic shoes fell off a ship heading from South Korea to Seattle, resulting in 80,000 floating shoes, most of which washed up on beaches across the Pacific Northwest. And in 2002, Nike lost three more containers carrying 33,000 sneakers. To its credit, Nike is one of the few companies that have admitted that those incidents occur.

So, how did Great Pacific Garbage Patch form and what keeps it together, even if loosely? It all has to do with large-scale ocean currents called gyres. The term is derived from Latin, gyrus, which came from Greek, guros, meaning circle. Author’s Note: For those keen-eyed readers who are interested in birding, gyre is unrelated to the prefix, gyr, as in gyrfalcon, which is derived from the German word for vulture, which it borrowed from only God knows where. The word, gyre, is pronounced, jire, as in j-eye-r and rhymes with geyer. The name for the bird is pronounced, jir-fal-con, as in jeer.

In oceanography, the macro-scale (planetary) circulation system currents in each major ocean basin result from a combination of the global prevailing wind system (trade winds and westerlies/easterlies) and the Coriolis Effect in what is known as geostrophic flow. For example, a given parcel of water beneath the trade winds will attempt to flow at a right angle to the winds owing to the influence of the Coriolis Effect (Ekman motion theory describes the wind driven portion of circulation seen at the surface). However, that current will run into a small slope caused by Ekman transport (in the Atlantic Ocean that hill of water is about six feet high). And, since we all know that water does not readily run uphill, the end result is the Coriolis Effect and the pressure gradient force will attain a balance, causing the wind-driven current to flow around the hill of water, creating a gyre.

A somewhat simpler explanation is that these wind-driven eastward- and westward-flowing equatorial currents are blocked by the continents and rotate slowly in a clockwise direction in the North Atlantic and Pacific Oceans and in a counter-clockwise direction in the South Atlantic, South Pacific, and Indian Oceans, piling up water in the center. Structurally, all gyres consist of a narrow, swift-flowing western boundary current, an eastward-flowing zonal current, a broad and slow-moving eastern boundary current, and a westward flowing zonal current. Eight gyres (listed as A through H) have been identified by physical oceanographers.

A) The Brazil, South Atlantic, Benguela, and South Equatorial Currents form the Southern Atlantic Subtropical Gyre.

B) The Northern Atlantic Subtropical gyre consists of the Gulf Stream, Azores, Canary, and North Equatorial Currents.

C) The Labrador, North Atlantic, Irminger, and East Greenland Currents form the Northern Atlantic Sub-polar Gyre.

D) The East Australian, South Pacific, Peru/Chile, and South Equatorial Currents constitute the Southern Pacific Subtropical Gyre.

E) The Kuro Siwo, North Pacific, California, and North Equatorial Currents form the Northern Pacific Subtropical Gyre.

F) The Oya Siwo, Aleutian, California, and Alaskan Currents and the Alaskan Stream form the Northern Pacific Sub-polar Gyre.

G) A second sub-polar gyre is found in the Bering Sea.

H) The Agulhas, South Indian, West Australian, and South Equatorial Currents form the only subtropical gyre in the Indian Ocean.

Scientists at the National Oceanic and Atmospheric Administration (NOAA) predicted the eventual formation of the Great Garbage Patch in a paper published in 1988. That prediction was based on earlier research performed between 1985 and 1988 by several Alaska-based oceanographers that measured minute or microscopic plastic fragments in the North Pacific Ocean. That research demonstrated the presence of high concentrations of marine debris accumulating in ocean areas influenced by large-scale, prevailing circular currents known as gyres.

In 1997, Charles J. Moore was sailing through the North Pacific Gyre and happened across an enormous stretch of floating debris. Moore alerted the oceanographer Curtis C. Ebbesmeyer, who later named the region the Eastern Garbage Patch. Author’s Note: Ebbesmeyer spent much of his career monitoring ocean currents by tracking buoys and markers dropped at sea. But, in retirement he began using flotsam as markers and encouraged environmentalists to become involved in raising public awareness of the problem. For more details, see: Curtis C. Ebbesmeyer and W. James Ingraham Jr., “Pacific Toy Spill Fuels Ocean Current Pathways Research,” Eos (American Geophysical Union), September 13, 1994.

Not many of us associate gyres with garbage, but if you take a close look at what is happening in the Northern Pacific Subtropical Gyre you might experience an awakening. The Northern Pacific Subtropical Gyre churns slowly in a clockwise flow between the U.S. West Coast and Japan driven by a circular wind system that basically is heated at the Equator and cooled at the North Pole. Several large expanses of placid water are formed at the centers of two sub-gyres, one located between the Hawaiian Islands and California and the other between Hawaii and Japan. A few variants on an accurate but uncomplimentary nickname have been given to these placid waters: the Great Garbage Patch, the Western Garbage Patch, the Eastern Garbage Patch, and the Great Pacific Garbage Patch. The reason is clear since the arms of the gyre collect flotsam that eventually winds up in the calm, nearly current-less central section. With a geographic extent that may be more than twice the size of Texas, the Eastern Garbage Patch is no laughing matter. And not because of its size but because it has become a Mecca of floating plastics (and other debris). Oceanographic research has shown that parts of the Eastern Garbage Patch have about six times as much plastic by weight than plankton.

The other general meaning of the word, gyre, is a circular or spiral form; a closed curving plane equidistant from a fixed point, or objects shaped like a band, circle, disk, ring, or wheel. Fun Stuff: The meaning, spiral form, is used in the first stanza of the marvelous and oft-quoted poem by William Butler Yeats, The Second Coming.

Turning and turning in the widening gyre

The falcon cannot hear the falconer;

Things fall apart; the centre cannot hold;

Mere anarchy is loosed upon the world,

The blood-dimmed tide is loosed, and everywhere

The ceremony of innocence is drowned;

The best lack all conviction, while the worst

Are full of passionate intensity.