Thursday, December 2, 2010

The Great Pacific Garbage Patch

In the middle of the north Pacific ocean is a region that is estimated to be anything between twice the size of Texas up to the size of the African continent containing some 2,500,000 tons of garbage.

Welcome to the Great Pacific Garbage Patch.

Trash floating in the Pacific gyre.  Photo by Cesar Harada

The world’s oceans each have more or less permanent currents that circulate through them: for example, the Gulf stream, the Humboldt current, the East-Australian current, the Equatorial counter-current.  These currents tend to form great circles on the map – clockwise in the northern hemisphere, counter-clockwise in the south – and in the centre of these regions (their ‘gyres’) the floating refuse (mostly long-lived plastics) is gradually accreting.

The oceans’ major currents and their gyres, from Wikipedia.

Some of the trash is still recognisable objects – bags, bottles, nets, even toilet seats (!) – but over time they start to break up so that the bulk of the trash is a giant cloud of small plastic particles.  This cloud is worse news than the larger pieces, as it essentially can’t be removed, the particles still pose serious hazards to marine life, and it may shade the water from the sun which slows the growth of plankton in these areas.

A sample of the region’s plastic “soup”, photo from Algalita Marine Research Foundation, via CNet

The image of a gigantic floating island of refuse seems very compelling to me.  Imagine those millions of tons of trash compressed together, mixed with dirt, seaweed, and dead fish and birds.  Could this be an alternative home for Dagon?  Perhaps the rotting hulks of abandoned ships are there too, ships that perhaps ran ‘aground’ (if that’s the right word).  I suppose this is now merging into something of the old popular image of the Sargasso Sea: located in a similar situation on the Atlantic ocean and named for the seaweed that grew there, it has often been imagined as something of a floating graveyard and a place of mystery.

Could someone have claimed this new territory as their domain, ruling from a decaying ship somewhere in the middle of this blighted floating land?  Is the land solid everywhere underfoot?  Are there sinkholes into the ocean beneath scattered around to trap the unwary, are there waterways through the mire?  What could be living beneath this land, what would survive in the toxic waters?  Perhaps it’s not stationary, perhaps it’s heading to the shore, perhaps even with the intent of invading?

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