The Great Pacific Garbage Patch

The plastic bag ban starts today here in Seattle.  They have been banned in other cities and other countries (they were jokingly called the “national flower” of South Africa because they seemed to bloom everywhere).  It won’t be a big deal.  We will adapt fine to bringing our own bags for groceries or paying five cents if for a paper bag if we forget.  We will be fine.  If you feel like it is a big deal, think about the amount of garbage that is already floating in a huge swirl in the Pacific Ocean, then suck it up and quit being a baby.

The Great Pacific Garbage Patch, also described as the Pacific Trash Vortex, is a gyre of marine litter in the central North Pacific Ocean located roughly between 135°W to 155°W and 35°N to 42°N. The patch extends over an indeterminate area, with estimates ranging very widely depending on the degree of plastic concentration used to define the affected area.

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. Despite its size and density, the patch is not visible from satellite photography, since it consists primarily of suspended particulates in the upper water column. Since plastics break down to even smaller polymers, concentrations of submerged particles are not visible from space, nor do they appear as a continuous debris field. Instead, the patch is defined as an area in which the mass of plastic debris in the upper water column is significantly higher than average.

Discovery

Map showing large-scale looping water movements within the Pacific. One circles west to Australia, then south and back to Latin America. Further north, water moves east to Central America, and then joins a larger movement further north, which loops south, west, north, and east between North America and Japan. Two smaller loops circle in the eastern and central North Pacific.

The Patch is created in the gyre of the North Pacific Subtropical Convergence Zone.

The Great Garbage Patch was predicted in a 1988 paper published by the National Oceanic and Atmospheric Administration (NOAA) of the United States. The prediction was based on results obtained by several Alaska-based researchers between 1985 and 1988 that measured neustonic plastic in the North Pacific Ocean. This research found high concentrations of marine debris accumulating in regions governed by ocean currents. Extrapolating from findings in the Sea of Japan, the researchers hypothesized that similar conditions would occur in other parts of the Pacific where prevailing currents were favorable to the creation of relatively stable waters. They specifically indicated the North Pacific Gyre.

Charles J. Moore, returning home through the North Pacific Gyre after competing in the Transpac sailing race in 1997, came upon an enormous stretch of floating debris. Moore alerted the oceanographer Curtis Ebbesmeyer, who subsequently dubbed the region the “Eastern Garbage Patch” (EGP).The area is frequently featured in media reports as an exceptional example of marine pollution.

A similar patch of floating plastic debris is found in the Atlantic Ocean.

Sources of pollutants

There is no strong scientific data concerning the origins of pelagic plastics. The figure that an estimated 80% of the garbage comes from land-based sources and 20% from ships is derived from an unsubstantiated estimate.  Ship-generated pollution is a source of concern, since 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.  Pollutants range in size from abandoned fishing nets to micro-pellets used in abrasive cleaners. Currents carry debris from the west coast of North America to the gyre in about six years,  and debris from the east coast of Asia in a year or less.  An international research project led by Dr. Hideshige Takada of Tokyo University of Agriculture and Technology studying plastic pellets, or nurdles, from beaches around the world may provide further clues about the origins of pelagic plastic.

Effect on wildlife

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, on the microscopic level 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.[33] 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.

On the macroscopic level, the physical size of the plastic kills birds and turtles as the animals’ digestion can not break down the plastic inside their stomachs. A second effect of the macroscopic plastic is to make it much more difficult for animals to see and detect their normal sources of food.

Research has shown that this plastic marine debris affects at least 267 species worldwide and a few of the 267 species reside in the North Pacific Gyre.

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