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by
Steven R. Van Hook, PhD
HowToSail.us
 The
New York Times reports that a pile of floating plastic debris some
1,000 miles northeast of Hawaii may now be double the size of Texas.
The garbage patch is caught up
in a gyre of heavy currents and slack winds, and swirls in a whirlpool
made of "light bulbs, bottle caps, toothbrushes, popsicle sticks and
tiny pieces of plastic, each the size of a grain of rice" and may be
doubling in size very ten years.
The Pacific garbage patch was accidentally
discovered more than a decade ago by Charles Moore during a sailing race off Hawaii.
Here's his TED
talk on the topic. Scientists believe other such plastic piles may be found off the coast of
Japan and in the Sargasso Sea centered in the Atlantic Ocean.
Researchers say that toxins
leaching from the piles are absorbed into fish tissue from the plastic
they eat, which in turn toxify humans further up the food chain.
Here is some additional data
on the gyre, courtesy of Greenpeace
International:
The North Pacific
sub-tropical gyre covers a large area of the Pacific in which the water
circulates clockwise in a slow spiral. Winds are light. The currents
tend to force any floating material into the low energy central area of
the gyre. There are few islands on which the floating material can
beach. So it stays there in the gyre, in astounding quantities estimated
at six kilos of plastic for every kilo of naturally occurring plankton.
This gyre has also been dubbed “the Asian Trash Trail” the “Trash
Vortex” or the “Eastern Garbage Patch”.
This perhaps wouldn’t be too much of a
problem if the plastic had no ill effects. The larger items, however,
are consumed by seabirds and other animals which mistake them for prey.
Many seabirds and their chicks have been found dead, their stomachs
filled with medium sized plastic items such as bottle tops, lighters and
balloons. A turtle found dead in Hawaii had over a thousand pieces of
plastic in its stomach and intestines. It has been
estimated that over a million sea-birds and one hundred thousand
marine mammals and sea turtles are killed each year by ingestion of
plastics or entanglement.
Animals can become entangled in discarded netting and line. Even tiny
jelly-fish like creatures become entangled in lengths of plastic
filament, or eat the small plastic particles floating in the water.
Chemical sponge
 There
is a sinister twist to all this as well. The plastics can act as a sort
of “chemical sponge”. They can concentrate many of the most damaging
of the pollutants found in the worlds oceans: the persistent organic
pollutants (POPs). So any animal eating these pieces of plastic
debris will also be taking in highly toxic pollutants.
The North Pacific gyre is one of five major ocean gyres and it is
possible that this Trash Vortex problem is one which is present in other
oceans as well. The Sargasso Sea is a well known slow circulation area
in the Atlantic, and research there has also demonstrated high
concentrations of plastic particles present in the water.
Ocean hitchhikers
The floating plastics can also affect
marine ecosystems in a surprising way, by providing a ready surface for
organisms to live on. These plants and animals can then be transported
on the plastic far outside their normal habitat. These ocean
hitch-hikers can then invade new habitats to become possible nuisance
species.
Of course, not all plastic floats. In fact around 70 percent of
discarded plastic sinks to the bottom. In the North Sea, Dutch
scientists have counted around 110 pieces of litter for every square
kilometre of the seabed, a staggering 600,000 tonnes in the North Sea
alone. These plastics can smother the sea bottom and kill the marine
life which is found there.
The issue of plastic debris is one that needs to be urgently addressed.
At the personal level we can all contribute by avoiding plastics in the
things we buy and by disposing of our waste responsibly. Obviously
though, there is a need to make ship owners and operators, offshore
platforms and fishing boat operators more aware of the
consequences of irresponsible disposal of plastic items.
With so many threats to the world oceans including pollution like the
plastic getting stuck in this huge trash vortex, overfishing and climate
change we urgently need to rescue marine biodiversity in the most
effective way possible.
You can
help today by joining
the call for a network of marine reserves that will protect 40% of
the world's oceans.
Source: Greenpeace http://www.greenpeace.org
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