[環保資訊] Giant Ocean-Trash Vortex Documented--A First

本帖最後由 dxb 於 2011-6-29 09:00 AM 編輯

PLEASE DO NOT DUMP TRASH INTO THE OCEAN or WATERWAYS...

September 4, 2009--Tangled with plastic, rope, and various aquatic animals, a "ghost net" drifts in August 2009 in the Eastern Pacific Garbage Patch, a loose, free-floating "dump" twice the size of Texas.

SEAPLEX (the Scripps Environmental Accumulation of Plastic Expedition) recently became the first dedicated research trip to study the science of the remote plastic vortex in the ocean between California and Hawaii.

While large pieces are common, the garbage patch is not an island of plastic, the team found on their 19-day expedition in August. Much of the debris is in the form of countless thumbnail-size scraps.

"I think the plastic-confetti metaphor is probably closest to the reality," said expedition member Jesse Powell, a doctoral student in biological oceanography at the Scripps Institution of Oceanography in California.

Debris from the Eastern Pacific Garbage Patch is displayed on SEAPLEX's research ship New Horizon in summer 2009.

Perhaps 10 percent of the 260 million tons of plastic produced worldwide each year ends up in the sea--much of it in the swirling currents of the North Pacific Gyre and other ocean vortices.

During the New Horizon's 1,700-mile (2,700-kilometer) cruise through the garbage patch, scientists dragged nets through the ocean a hundred times. Each troll yielded plastic debris--a "pretty shocking" result, said Scripps biological oceanography doctoral student Miriam Goldstein.

"In the ocean it's pretty unusual to find exactly what you're looking for over and over and over again," added Goldstein, principal investigator on the expedition.

In summer 2009, SEAPLEX scientists netted animal inhabitants of the Eastern Pacific Garbage Patch including myctophid fish (top), flying fish (middle), and squid--commingled with ubiquitous bits of plastic.

Researchers are keen to learn how the massive influx of plastic pieces in recent decades affects area animals, from larger creatures such as fish and birds--which swallow toxic plastic--to tiny organisms such as bacteria or plankton. The plastic may also be hosting invasive bacteria or other species, researchers say.

Many pieces are about the size of small marine animals--a potential problem. "Any sort of net technology that you'd use to pull out plastic 'confetti' is obviously going to capture a lot of native species as well," SEAPLEX member Jesse Powell said.

A researcher in the Eastern Pacific Ocean Patch in August 2009 holds some of the many plastic bottles that have been "recycled" into homes by marine animals.

"Almost every large piece of plastic debris had a community of gooseneck barnacles or small [ocean-going] crabs, and smaller fish beneath it like rainbow runners or baby yellowtail," SEAPLEX member Jesse Powell said.

"The fact that there are all these mini [plastic] island ecosystems floating out there right now, each with its own predatory inhabitants, may have some sort of implications for the food web."

A tiny crab crawls on plastic retrieved from the Eastern Pacific Garbage Patch in August 2009.

The expedition easily spotted some types of plastic. But a larger problem may lurk below the surface.

The SEAPLEX team collected data on the extent of the garbage patch at the surface and the oceanographic conditions there. But no one knows how prevalent plastic may be below the surface.

What's more, this isn't the world's only vast ocean garbage patch, or even the biggest. Scripps Institution scientists hope to soon visit a massive garbage patch off South America about which even less is known.

Found floating in a fishing net in August 2009, this stuffed dog was hauled onboard and christened Lucky. It became SEAPLEX's unofficial mascot.

Lucky's rescue brought home a startling statistic: An estimated 80 percent of the trash in the Eastern Pacific Garbage Patch was simply discarded by people on shore, according to Doug Woodring of Project Kaisei, an ocean-health nonprofit that collaborated with SEAPLEX. Cutting down on that type of waste is likely the best way to begin cleaning up the world's oceans, the researchers say.

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