A portion of the Great Pacific Garbage Patch, copyright Scripps Institution of Oceanography

   from Earth magazine, January 24, 2012

In his book, Plastic Ocean, Charles Moore, marine environmental researcher, writes about his 1997 experience of taking his catamaran through what has since been dubbed the Great Pacific Garbage Patch.

It took Moore and his crew seven days to cross the area, during which they saw a vast sea of floating garbage composed primarily of plastic.  Larger debris floated on the surface with smaller pieces suspended below in a water column.  Estimates of the area Moore crossed are between 700,000 and 15,000,000 square kilometers.  Some researchers estimate the area as the size of Texas.

Only 1% of the more than the 260,000,000 tons of plastic produced globally is recycled. 

Almost one-third of the total tonnage represents disposable, one-time use plastics—think water bottles—ends up in landfills. 

Or in our oceans, carried by vast, rotating currents and gyres to form three enormous garbage patches in the Pacific Ocean and two in the Atlantic.

            photo of a garbage dump in the North Atlantic, courtesy NASA’s Earth Observer

About 80% of the garbage comes from land-sources, carried by wind, streams or rivers to the oceans.  Extreme hurricanes, tornadoes, tsunamis, floods and mudslides deposit huge amounts of debris far out to sea; the Japan tsunami of a year ago sent about 20 to 40,000,000 tons of debris into the Pacific Ocean.

Another 20% of the garbage comes from ocean transportation:  military fleets and research, cruise, shipping and fishing vessels.

All the plastic garbage becomes concentrated and trapped by the rotating currents and isn’t evenly distributed in the ocean. 

Eventually, wave action and ultra violet light weather it into smaller pieces, which become weighted down by microbial biofilms, gradually sinking to depths where deep currents carry it away from the garbage patch.

No one knows how long plastics take to completely degrade or even if they do.

Researchers are currently working to identify and quantify the contents of the patches and to determine how fast they’re growing, how fast the plastics degrade and how they’re affecting marine ecosystem

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