There are now 46,000 pieces of plastic per square kilometre
of the world's oceans, killing a million seabirds and
100,000 marine mammals each year. Worse still, there
seems to be nothing we can do to clean it up.
(The United Nations Environment Programme
says around 13,000 pieces of plastic litter are found in every
square kilometre
of sea, but the problem is worst in the North Pacific)
Courtesy: NOAA
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Way out in the Pacific Ocean, in an area once known as the doldrums,
an enormous, accidental monument to modern society has
formed. Invisible to satellites, poorly understood by scientists
and perhaps twice the size of France, the Great Pacific
Garbage
Patch is not a solid mass, as is sometimes imagined, but a kind
of marine soup whose main ingredient is floating plastic debris.
It was discovered in 1997 by a Californian sailor, surfer,
volunteer environmentalist and early-retired furniture restorer
named
Charles Moore, who was heading home with his crew from a sailing
race in Hawaii, at the helm of a 50ft catamaran that he had
built himself.
He decided to turn on the engine and take a shortcut across
the edge of the North Pacific Subtropical Gyre, a region that
seafarers
have long avoided. It is a perennial high pressure zone, an
immense slowly spiralling vortex of warm equatorial air that
pulls in
winds and turns them gently until they expire. Several major
sea currents also converge in the gyre and bring with them
most of
the flotsam from the Pacific coasts of Southeast Asia, North
America, Canada and Mexico. Fifty years ago nearly all that
flotsam
was biodegradable. These days it is 90 per cent plastic.
The size of the patch is unknown,
as large items readily visible from a boat deck are uncommon.
Most debris consists of
small plastic particles suspended at or just below the
surface, making it impossible to detect by aircraft or
satellite. Instead,
the size of the patch is determined by sampling. Estimates
of size range from 700,000 square kilometres (270,000
sq mi) to
more than 15,000,000 square kilometres (5,800,000 sq mi)
(0.41% to 8.1% of the size of the Pacific Ocean), or,
in some
media reports, up to "twice the size of the continental
United States".[10] Such estimates, however, are
conjectural based
on the complexities of sampling and the need to assess
findings against other areas.
http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch,
Download May 21st, 2012 |
Photo: © http://greatpacificgarbagepatch.info/
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'Bottle caps, toothbrushes, styrofoam cups, detergent bottles,
pieces of polystyrene packaging and plastic bags. Half of
it was just little chips that we couldn't identify. It wasn't
a revelation so much as a gradual sinking feeling that something
was terribly wrong here.' What is YOUR opinion? Is something
wrong out there?
Floating beneath the surface of the water, to a depth
of 10 metres, was a multitude of small plastic flecks and
particles, in many colours, swirling like snowflakes or fish
food.
The world's navies and commercial shipping fleets make
a significant contribution, he discovered, throwing some 639,000
plastic
containers overboard every day, along with their other litter.
But after a few more years of sampling ocean water in the
gyre and
near the mouths of Los Angeles streams, and comparing notes
with scientists in Japan and Britain, Moore concluded that
80 per
cent of marine plastic was initially discarded on land,
and the United Nations Environmental Programme agrees.
Does that mean that the amount dicarced on land amounts to
about 2.500.000 plastic containers, daily???
Plastic does not biodegrade; no microbe has yet evolved
that can feed on it. But it does photodegrade. Prolonged exposure
to
sunlight causes polymer chains to break down into smaller
and smaller pieces, a process accelerated by physical friction,
such as
being blown across a beach or rolled by waves. This accounts
for most of the flecks and fragments in the enormous plastic
soup
at the becalmed heart of the Pacific,
Laysan
albatross flying in air
Photo:
Lusk, Michael / FWS (http://www.fws.gov/midway )
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On Midway Island, 2,800 miles west of California and 2,200
miles east of Japan, the British wildlife filmmaker Rebecca
Hosking
found that many thousands of Laysan albatross chicks
are dying every year from eating pieces of plastic that their
parents mistake
for food and bring back for them.
Worldwide, according to the United Nations Environment
Programme, plastic is killing a million seabirds a year, and
100,000
marine mammals and turtles. It kills by entanglement, most
commonly in discarded synthetic fishing lines and nets. It
kills by
choking throats and gullets and clogging up digestive tracts,
leading to fatal constipation. Bottle caps, pocket combs,
cigarette
lighters, tampon applicators, cottonbud shafts, toothbrushes,
toys, syringes and plastic shopping bags are routinely found
in
the stomachs of dead seabirds and turtles.
A study of fulmar carcases that washed up on North Sea coastlines
found that 95 per cent had plastic in their stomachs –
an average of 45 pieces per bird.
Effect on wildlife
Olive
Ridley Sea Turtle, Lepidochelys olivacea
Photo: Thierry Caro
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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. 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.
http://en.wikipedia.org/wiki/Great_Pacific_Garbage_Patch,
Download May 21st, 2012 |
The Great Pacific Garbage Patch has now been tentatively
mapped into an east and west section and the combined weight
of plastic there is estimated at three million tons
and increasing steadily. It appears to be the big daddy of
them all,
but we do not know for sure.
A dead albatross was found recently with a piece of plastic
from the 1940s in its stomach. Even if plastic production
halted
tomorrow, the planet would be dealing with its environmental
consequences for thousands of years, and on the bottom of
the oceans, where an estimated 70 per cent of marine plastic
debris ends up – water bottles sink fairly quickly –
for tens
of thousands of years. It may form a layer in the geological
record of the planet, or some microbe may evolve that can
digest
plastic and find itself supplied with a vast food resource.
In the meantime, what can we do?
What we cannot do is clean up the plastic in the oceans. 'It's
the biggest misunderstanding people have on this issue,' Moore
says.
'They think the ocean is like a lake and we can go out with
nets and just clean it up. People find it difficult to grasp
the true size of
the oceans and the fact that most of this plastic is in tiny
pieces and it's everywhere. All we can do is stop putting
more of it in, and
that means redesigning our relationship with plastic.'
Based on an article: http://www.telegraph.co.uk/earth/environment/5208645/Drowning-in-plastic-The-Great-Pacific-Garbage-Patch-is-twice-the-size-of-France.html,
May 21st, 2012.
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