Karela Fry

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Plastic beaches, toxic oceans

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Telegraph recounts:

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.

Discover takes up the story:

Tangled with plastic, rope, and various aquatic animals, a "ghost net" drifts in August 2009 in the Eastern Pacific Garbage Patch

Moore, 61, is a scruffy sea captain whose blue eyes are both sad and keen. His salt-and-pepper hair is typically covered by an odd-fitting hat (“Die Trying” emblazoned across its brow). He is, as most sailors go, an old salt.

“In the central North Pacific Gyre, pieces of plastic outweigh surface zooplankton by a factor of 6 to 1,” according to a report based on Moore’s research. “Ninety percent of Laysan albatross chick carcasses and regurgitated stomach contents contain plastics. Fish and seabirds mistake plastic for food. Plastic debris releases chemical additives and plasticizers into the ocean. Plastic also adsorbs hydrophobic pollutants like PCBs and pesticides like DDT. These pollutants bioaccumulate in the tissues of marine organisms, biomagnify up the food chain, and find their way into the foods we eat.”

You’ll notice the emphasis on plastics. Most other materials biodegrade or are not as buoyant as plastics, which do not biodegrade. Their resilience is also their menace, as today plastics have invaded the most distant places, from the Bering Sea to the South Pole. Indeed, when I was exploring a remote beach past the South Point of Hawaii, I found pill bottles from India and mashed pieces of various products—oil containers, detergent jugs, plastic caps—with Russian, Korean, and Chinese writing on them. It’s hard to get your brain around these connections. But float these things did, to shore.

The Pacific garbage patch

The problem may have been first identified in the Pacific, but it is not confined there. The map above gives the location of the 5 major oceanic garbage patches all across the world. National Geographic wrote about the Atlantic gyre:

A new study suggests that microscopic bits of plastic have sifted, unseen, throughout the marine environment. The plastic not only litters the beach, it is—like fine bits of sand—becoming the beach.

U.K. researchers in Plymouth and Southampton, England, found that microscopic fragments of nylon, polyester, and seven other types of plastic are widespread in sediments around British shores.

The sediments were collected from beaches, estuaries, and shallow waters. “Everything that didn’t look like a piece of natural organic debris was then identified,” said Richard Thompson, a senior marine ecology lecturer at the University of Plymouth, who led the study. Up to a third of this material was later identified as synthetic polymers used in plastics.

Beyond plastic-enriched shorelines, the team found that plastic particles are now common in the high seas.

To gauge long-term trends, the scientists examined plankton samples collected over the past 40 years in shipping lanes between Iceland and Scotland. Results showed there was approximately three times more plastic in the water column in the 1990s compared with the 1960s.

“Estimates for the longevity of plastic range from a hundred to a thousand years,” Thompson said. “Since we’ve only been [mass producing] plastics for 40 years, we still don’t have a full handle on their longevity.”

The impact of larger plastic flotsam on marine wildlife is well documented. According to the U.K.’s Marine Conservation Society, a national environmental nonprofit, more than a million seabirds and 100,000 mammals and sea turtles die globally each year from entanglement in, or ingestion of, plastics.

While most plastics are non-biodegradable, Thompson says the action of waves and the elements work to break plastic objects down into fragments tiny enough to be ingested by countless other marine organisms.

To test the potential for this to occur, Thompson and his colleagues kept barnacles, lugworms, and detritus-eating amphipods in aquaria with small amounts of microscopic plastics. These invertebrates all ingested the fragments within a few days.

Many plastics contain toxic chemicals, including biocides (to prevent organisms colonizing their surfaces), colorings, and flexibility-enhancing agents known as plasticizers. These substances could be released if the plastics were eaten.

Thompson added: “Another possibility, recently shown by researchers in Japan, is that when plastics are floating in the seas, they will accumulate and absorb toxic chemicals that are present from other sources. These are hydrophobic chemicals that hate to be in water and cling to plastic as an alternative. These chemicals may then be transported to organisms that eat the plastic.”

Such toxic chemicals include PCBs (polychlorinated biphenyls) and DDE (dichlorodiphenyldichloroethylene), which are derived from pesticides and other manmade substances. These agents are known endocrine disruptors—chemicals that interfere with the reproductive, developmental, and immune systems of animals.

The 5 gyres

Why should we care? Discover has this to say:

The Alguita’s journey last winter was closely followed by the many who had become aware of the floating garbage dump. Crew members kept a ship-to-shore blog, writing: “We know this plastic trash is a problem…. But in order to get the world to pay attention and start making changes, we need to prove it. We need accurate data and real hard numbers, so we can bring this information to governments, industries, and the public and show them just how serious this issue has become.”

Blog responses came from all over the world, from grade-school children to the elderly, scientists to laypeople.

One asked, “Do we have an answer to the question ‘Yeah, it’s gross, but why should I put it high on my list of world problems that need our immediate attention?’?” It is a good question because marine pollution is one of the most underreported stories today. One glaring answer to the question is this: Around 2.5 billion people rely upon fish for at least 20 percent of their animal protein. When fisheries get polluted, so does the food we eat.

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Written by Arhopala Bazaloides

July 9, 2011 at 4:59 am

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