If there’s any good to come from the frustrating search for the missing Malaysian Airlines flight, it’s this: Each time debris spotted in the ocean turns out not to be from the aircraft, it demonstrates to the millions of people following the story that’s there another important one to know about: garbage.

Scientists have been trying for years to draw attention to the growing problem of trash, big and small, floating throughout the world’s oceans. Inadvertently, the search for Flight 370 has brought this environmental issue front and center each time objects spotted west of Australia have had nothing to do with the plane, but everything to do with how mankind has treated the ocean as a dumping ground.

The debris spotted on several occasions are part of a swirling mass, or gyre, in the southern Indian Ocean, one of five such gyres churning on the high seas.

The largest gyre, according to experts, is located between Hawaii and California. It’s about 270,000 square miles in size, making it about as big as Texas.

These gyres contain mostly tiny pieces of plastic, the result of larger items gradually broken down over time by the sun and waves. But there are also larger items—like refrigerators and lost shipping containers—which can be found bobbing along the surface, kept afloat due to the air pockets trapped inside them.

The number of steel shipping containers that fall overboard off of cargo ships each year is staggering: from 700 to 10,000. With them go their contents, be it computers, toys, clothing, appliances and more. One container released a seemingly endless supply of Legos into the sea, another dumped 2,000 computer monitors, and yet another unloaded thousands of Nike sneakers into the ocean, according to one oceanographer.

Natural disasters also contribute to the garbage problem. The 2011 tsunami that struck Japan swept 10 million tons of debris—including homes, cars and trees—into the Pacific.

“The ocean is like a plastic soup, bulked up with the croutons of these larger items,” Los Angeles captain Charles Moore told the Associated Press. “It’s like a toilet bowl that swirls but doesn’t flush,” added Moore, whose environmental activism has brought attention to the northern Pacific gyre. Appropriately, perhaps, he has found toilet seats in the ocean, along with light bulbs, fishing paraphernalia, and defrosted orange juice preserved inside a floating fridge.

Denise Hardesty, a research scientist for Australian science agency CSIRO, says the non-biodegradable items will remain in the ocean for centuries.

“It takes 400 or 500 years for lots of types of plastics to completely break down,” Hardesty told the AP. “It just goes into smaller and smaller bits. You even find plastics in plankton — that's how small it gets.”

These small items are dangerous to aquatic life, noted Hardesty. Two-thirds of the sea birds she has examined had ingested plastic. One bird had swallowed a glow stick that was several inches long, and another bird was found to have consumed 175 plastic pieces.

-Noel Brinkerhoff

To Learn More:

Sea Garbage Frustrates Search for Flight 370 and Points to Wider Problems in World's Oceans (by Nick Perry, Associated Press)

Missing Jet Search Makes One Thing Clear: Indian Ocean Full of Trash (by Angela Mulholland, CTV News)

Plane Search Hampered by Ocean Garbage Problem (by Tom Cohen, CNN)

What is the Great Pacific Ocean Garbage Patch? (by Russell McLendon, Mother Nature Network)

Natural and Plastic Flotsam Stranding in the Indian Ocean (by David K.A. Barnes, The Effects of Human Transport on Ecosystems: Cars and Planes, Boats and Trains) (pdf)

Plastic Pollution in the Atlantic Ocean (by David Wallechinsky and Noel Brinkerhoff, AllGov)