Toying around with Ocean Currents

Adrift.org screenshot
If you drop a flotilla of duckies near San Diego, most of them end up in the North Pacific Gyre, a.k.a. the Great Pacific Garbage Patch.

A few years ago, I joined a clean-up at Kamilo Beach on the Big Island of Hawai’i.  I noted the things we found:

  • fishing gear
  • whale vertebrae
  • a glass float
  • hagfish traps
  • shoes
  • possible tsunami debris from Japan
  • top of a toy rocket
  • action figures
  • wheels from a toy car
  • toothbrushes
  • lighters

That list has been stashed on my phone for two years.

Why?

Because each item tells a story, from forgotten toys to mislaid fishing nets.  Each piece of flotsam was made, lost, and carried across the Pacific to the world’s most isolated island chain.

I wanted to learn that story.  And, if you’ve ever lost a flip-flop at a beach, or written a message in a bottle, you might want to learn where it went.

You can find out at one of my favorite sites, Adrift.

In 1992, 30,000 rubber ducks and other bath toys fell from a container ship into the Pacific Ocean.  By the end of the year, those toys – the so-called “Friendly Floatees” –  were washing up on shores in Alaska.  Fifteen years later, more toys made their way as far as the United Kingdom.

Scientists used these Floatees to trace ocean currents, and offered rewards to any beachcomber who recovered one.  These toys are immortalized in the book Moby-Duck (disclaimer: I haven’t read it yet, though it’s been on my reading list for a while now).

Those rubber ducks inspired Adrift, and if you didn’t click the link earlier, check it out now.  Find your favorite beach (or any spot in the ocean, really) and drop a bunch of duckies.  Where do they go, and how fast do they get there?

If you drop your ducks near the tip of South America, for example, the world’s strongest current carries them everywhere from Australia to Africa:

Adrift screenshot Argentina
The Antarctic Circumpolar Current carries these duckies around the globe, from the South Pacific to the South Atlantic and Indian Ocean.

 

Adrift screenshot gyre
Ducks trapped in the South Pacific gyre.  In a gyre, no one can hear you quack.

But, in other parts of the ocean, the duckies hardly move at all:This is an example of a gyre.  There are five major gyres: the South Pacific (pictured above), the North Pacific (title image), North and South Atlantic, and Indian Ocean Gyres.  They’re the centers of rotating ocean currents, like the axis of a wheel, or the core of a tornado.  And, like a tornado, they tend to suck up a lot of debris.

That debris includes a lot of trash.  The North Pacific gyre has accumulated so much junk that it’s become the Great Pacific Garbage Patch.  That patch is filled with plastics that have been degraded by sunlight and weathering into tiny pellets, turning the gyre into a “plastic soup” that is nearly impossible to clean.  Dr. Erik van Sebille does a great job of explaining this process:

These plastics come from a range of sources, from commercial fishing gear to tsunami debris.  But, the overwhelming bulk of this trash comes from household items: plastic flossers, solo cups, and even the tiny plastic microbeads in your cosmetics, hand sanitizer, and toothpaste.

Most plastics can endure 400-1000 years.  This material, originally designed to last forever, has become the standard for disposable items.

How long is 1000 years, really?

Well, let’s put it this way.  Diamonds are forever, right?  Wrong.  Your diamond is slowly flaking away into graphite.  Wait a few thousand years, and your mom’s engagement ring could become a dusting of pencil lead.

That means that, within an order of magnitude, your plastic fork could last as long as a diamond.

Plastics are the fossils of the future.

The year after my beach clean-up, visitors to Kamilo Beach began finding “plastiglomerates,” plastics fused by heat with sand, shells, and corals into a new type of rock.

Fossils tell us about past worlds, from a time when palm trees flourished in Antarctica to a world where Boston was buried beneath four thousand feet of ice.

What do plastic rocks say about the world we live in?

In future millennia, scientists might dig up a plastiglomerate and mark it as the beginning of a world dominated not by trilobites, dinosaurs, or mammoths, but by man: the “Anthropocene.”

I loathe the term “Anthropocene” (that’s a rant for another day), but it emphasizes the fact that every action we take has a legacy, a consequence.

As I walked along Kamilo Beach, I bent down and examined a flip-flop, no bigger than my fist.  Did its owner know that this baby shoe had wandered to a remote beach in Hawai’i?  Probably not.

I had a pair of flip-flops as a child.  I don’t know what happened to them.  They might be in my parents’ attic, or on the shelves at Goodwill.  But maybe, just maybe, they escaped from a garbage barge into the ocean.

I picked up the shoe and put it in my trash bag.

 

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