Imagine motoring from Hawaii to California through the North Pacific subtropical gyre, an immense region of the ocean where high pressure rules, trade winds fail, and currents trace a circle many hundreds of miles across, corralling anything that floats into a slowly rotating vortex.

A few days off Hawaii, you notice something odd about the sea around you: it bubbles with a subsurface "soup" of plastic trash, from soccer balls and kayaks to water bottles, snarls of polypropylene rope, and discarded shopping bags.

This layer of human-produced detritus extends thirty feet deep, is in constant motion, and you pass through it for days.

You've encountered the Great Pacific Garbage Patch, an enormous and accidental floating dump first described in 1997 by George Moore, founder of the Algalita Marine Research Foundation.

Moore was taking a "short-cut" home from a Los-Angeles-to-Hawaii sailboat race, and decided to motor across the gyre to save time. He was astonished to discover the bubbling trash stew that stretched off his bow as far as the eye could see, and dismayed that that it took an entire week to pass through this unplanned marine dump.

So dismayed, in fact, that when he returned to California, Moore sold his business interests and founded a research institute specifically to study the ocean garbage patch and see what could be done about it.

At that time, Moore estimated the floating soup of debris covered an area of ocean the size of the state of Texas.

This spring, Moore and his staff returned from their bi-annual survey with bad news: the floating garbage gyre has expanded to form two trash gyres hundreds of miles across, on either side of the Hawaiian islands: the Eastern Pacific Garbage Patch, extending from just off Hawaii nearly to Japan, and the Western Pacific Garbage Patch, stretching between Hawaii and California.

Together the two swirling vortexes of suspended trash cover an area twice the size of the continental United States, containing an estimated 100 million tons of flotsam.

These immense layers of floating plastic and other debris are not just unsightly. Algalita researchers estimate that plastic fragments in the North Pacific subtropical gyre now outweigh surface zooplankton by 6 to 1, or six pounds of plastic to every pound of edible organisms.

This bubbling stew of human-made discards is deadly to seabirds and marine animals, who mistake the plastic fragments for food.

Take Leatherback sea turtles. These enormous and long-lived marine animals have been around since the time of the dinosaurs and normally feed on jellies, diving almost a mile deep and swimming thousands of miles in search of concentrations of their favorite food.

But plastic shopping bags mimic jellies' drifting progress through the water, complete with partially inflated "bells" since the bags trap air. When six-foot-long leatherbacks encounter "swarms" of plastic bags, they may fill their gullets with these indigestibles and subsequently starve to death.

It's not just turtles who are fooled by the trash soup. The United Nations Environment Program estimates that more than 1 million seabirds die from ingesting this trash each year, and upwards of 100,000 marine mammals.

Plastic never completely decays, and its synthesized molecules sop up some of our worst pollutants, accumulating non-water-soluble compounds including DDT and PCBs at up to one million times the levels they occur in the ocean.

The poison-laden fragments are then ingested by "vacuum-feeding" sea organisms, which in turn are eaten by larger marine predators, including fish--and who eats the fish? Humans.

So next time you find yourself tempted to buy what singer Nancy Griffith calls "unnecessary plastic objects," imagine those twin layers of discarded plastic stew slowly rotating in the Pacific Ocean with their deadly impacts, and think again.

Copyright 2008 Susan J. Tweit
First printed in the Salida, Colorado, Mountain Mail, and aired on KHEN-FM community radio.

The artwork for this podcast is a painting of California's Big Sur Coast by my great-grandmother, Jennie Vennerstrom (JV) Cannon.