Friday, March 23, 2018

The Great Pacific Garbage Patch

The Great Pacific Garbage Patch is a misnomer, but it's the best description we have of the over 600,000 square mile (more than twice the size of the state of Texas) trash accumulation in the Pacific Ocean.  It is also described as the Pacific trash vortex, and is a gyre of marine debris particles in the central North Pacific Ocean, between Hawaii and California, that was discovered between 1985 and 1988.
   The patch is characterized by exceptionally high relative pelagic concentrations of plastic, chemical sludge, and other debris that have been trapped by the oceanic currents of the North Pacific Gyre.  Its low density (4 particles per cubic meter) prevents detection by satellite imagery, or even by casual boaters or divers in the area.
  There has been some controversy surrounding the use of the term "garbage patch," and photos taken off the coast of Manila in the Philippines in attempts to portray the patch in the media often misrepresent the true scope of the problem, and what could be done to solve it.  Angelicque White, Associate Professor at Oregon State University, who has studied the "garbage patch" in depth, warns that "the use of the phrase 'garbage patch'is misleading.  ...  It is not visible from space; there are no islands of trash; it is more akin to a diffuse soup of plastic floating in our oceans."  In a media article Dr. White and Professor Tamara Galloway, from the University of Exeter, call for regulation and cleanup, and state that the focus should be on stemming the flow of plastic into the ocean from coastal sources.   The United States National Oceanic and Atmospheric Administration (NOAA) agrees, stating: "While 'Great Pacific Garbage Patch' is a term often used by the media, it does not paint an accurate picture of the marine debris problem in the North Pacific Ocean.  The name 'Pacific Garbage Patch' has led many to believe that this area is a large and continuous patch of easily visible marine debris items such as bottles and other litter - akin to a literal island of trash that should be visible with satellite or aerial photographs.  This is not the case." (From Ocean Facts, National Ocean Service.)
   Microplastics make up 94 percent of an estimated 1.8 trillion pieces of plastic in the patch.  But that only amounts to 8 percent of the total tonnage.  As it turns out, of the 79,000 metric tons of plastic in the patch, most of it is abandoned fishing gear - not the plastic bottles or packaging that is drawing headlines today.
   A new comprehensive study by a team of scientists, published in Scientific Reports on Thursday, concluded that the 79,000 tons was 4 to 16 times larger than has been previously estimated for the patch.  The study also found that fishing nets account for 46 percent of the trash, with the majority of the rest composed of other fishing industry gear, including ropes, oyster spacers, eel traps, crates and baskets.  Scientists estimate that 20 percent of the debris is from the catastrophic 2011 Japanese tsunami.
   Laurent Lebreton, an oceanographer with Ocean Cleanup, and the study's lead author, says the research team was looking to assess the larger pieces of trash.   "I knew there would be a lot of fishing gear, but 46 percent was unexpectedly high," he says.  "Initially, we thought that fishing gear would be more in the 20 percent range.  That is the accepted number (for marine debris) globally - 20 percent from fishing sources and 80 percent from land."
    Ghostnets, a term coined to describe purposely discarded or accidentally lost netting, drift through the ocean, entangling whales, seals, and turtles,  An estimated 100,000 marine animals are strangled, suffocated, or injured by plastics every year.

  But wait!  There's more!!   There are also two garbage patches in the Atlantic Ocean.  -  The North Atlantic Garbage Patch was originally documented in 1972.  The patch is estimated to be hundreds of kilometers across in size, with a density of over 200,000 pieces of debris per square kilometer.  The debris zone shifts by as much as 1,600 kilometers (990 miles) north and south seasonally, and drifts even farther south during the El Nino Southern Oscillation, according to NOAA. - Not to mention the South Atlantic Garbage Patch....
  To study the scale of marine debris accumulation in the area, the Sea Education Association (SEA) has been doing extensive research on the North Atlantic Garbage Patch.  Nearly 700,000 students from the SEA semester program have been dragging 6,100 fine-mesh nets through the Atlantic over a period of 22 years.  The gyre in the North Atlantic contains plastic marine pollution in a pattern and amount similar to what has been found in the Great Pacific Garbage Patch.

And it is a global concern.  On 11 April 2013, in order to create awareness, artist Maria Cristina Finucci founded The Garbage Patch State at UNESCO-Paris in front of Director General Irina Bokova.  This was the first of a series of events under the patronage of UNESCO and of the Italian Ministry of the Environment.

I urge you to write to your political leaders, wherever you live, to pass legislation to keep our oceans clean, and to help clean out what is already in them!

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