The five major ocean gyres

For some reason, “G” was a real bitch. Oh sure, I considered writing about Greta Garbo. I considered “guillotine” but that word will figure quite prominently in “S” so it will have to wait.

I had a couple of other fleeting ideas, but they were not able to attach themselves to functional brain cells, so they are gone. For good. Maybe the title of this post should have been “Gone for Good.” Oh well.

Now it’s less than 90 minutes before I have to go to work and I’m staring at a blank form on my “new post” page. Arrrgh!

So there I was in bed, unable to sleep, so of course I was thinking, “What will I do for the ‘G’ post? Is ‘gyre’ even a word? If I played it in Scrabble I bet I’d get challenged!”

I knew I’d heard the word before. The internet provided the answer:

A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis Effect; planetary vorticity along with horizontal and vertical friction, which determine the circulation patterns from the wind curl (torque). The term gyre can be used to refer to any type of vortex in the air or the sea, even one that is man-made, but it is most commonly used in oceanography, to refer to the major ocean systems. (Wikipedia.)

Oh yes! Now I remember. Isn’t that interesting? Eh, no? Perhaps we can add a little human drama that makes it more compelling.

Scientists retrieved myriad plastic bottles, many with an assortment of inhabitants.

The northern Pacific Ocean is the location of the North Pacific Gyre, one of the five major oceanic gyres. Besides that interesting factoid, it has another, more remarkable characteristic. It is also home to the Great Pacific Garbage Patch.

Estimated to cover an area approx. twice the size of Texas, The Patch is the site of an unusually intense collection of man-made marine debris.

The Patch is characterized by exceptionally high concentrations of pelagic plastics, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre. The Patch is characterized by exceptionally high concentrations of pelagic plastics, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre.

It is estimated that the source of pollution which ends up in The Patch comes from land-based and ship-based sources. For example, “a typical 3,000 passenger cruise ship produces over eight tons of solid waste weekly, a major amount of which ends up in the patch, as most of the waste is organic.” Also, pollutants from the west coast of the United States can reach The Patch in about six years while pollution from the east coast of Asia can take one year or less.

A piece of plastic floating at the surface carries a crab, algae and masses of flying fish eggs.

The Great Pacific Garbage Patch has one of the highest levels known of plastic particulate suspended in the upper water column. As a result, it is one of several oceanic regions where researchers have studied the effects and impact of plastic photodegradation in the neustonic layer of water. Unlike debris, which biodegrades, the photodegraded plastic disintegrates into ever smaller pieces while remaining a polymer. This process continues down to the molecular level.

As the plastic flotsam photodegrades into smaller and smaller pieces, it concentrates in the upper water column. As it disintegrates, the plastic ultimately becomes small enough to be ingested by aquatic organisms which reside near the ocean’s surface. Plastic waste thus enters the food chain through its concentration in the neuston.

Some plastics decompose within a year of entering the water, leaching potentially toxic chemicals such as bisphenol A, PCBs and derivatives of polystyrene.

And, in a bit of planetary karma:

Some of these long-lasting plastics end up in the stomachs of marine birds and animals, and their young, including sea turtles and the Black-footed Albatross. Besides the particles’ danger to wildlife, the floating debris can absorb organic pollutants from seawater, including PCBs, DDT, and PAHs. Aside from toxic effects, when ingested, some of these are mistaken by the endocrine system as estradiol, causing hormone disruption in the affected animal. These toxin-containing plastic pieces are also eaten by jellyfish, which are then eaten by larger fish. Many of these fish are then consumed by humans, resulting in their ingestion of toxic chemicals. Marine plastics also facilitate the spread of invasive species that attach to floating plastic in one region and drift long distances to colonize other ecosystems.

Pollution from The Patch is estimated to impact at least 267 species worldwide.

Links:
http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch
http://www.nsf.gov/news/news_images.jsp?cntn_id=115481

This is my “G” post for the April 2011 “A to Z Blogging Challenge.”