Life aquatic choked by plastic

Something has crept up on us in the night - transformed our world beyond our imaginings. It's the stuff of sci-fi, but plastic jettisoned on land, even hundreds of kilometres from the coast, has turned the earth's oceans into a synthetic soup - and it seems impossible to fix.

"Plastic dumped in the gutters, storm-water drains and rivers of Asia and North America eventually finds its way to the Pacific, where salt water and sun photo-degrade it into tiny, even microscopic, flecks that are then picked up by the North Pacific gyre, a swirling mass ofocean currents," says Marieta Francis, executive director of the California-based Algalita Marine Research Foundation, which brought the phenomenon to the world's attention in 1997.

"It's called the Great Pacific Garbage Patch, but it's not a massive trash heap floating in the middle of the ocean; rather, billions of bits of plastic spread across the North Pacific - although you will find bigger trash, too, like plastic buckets and fishing nets."

Most descriptions compare the extent of this patch to an area twice the size of Texas.

"But we've been studying this problem for 11years and we're still not sure how large it is - our trawlers have found plastic stretching from California all the way to the international dateline - that is halfway to Japan. We haven't gone any farther than that, but we're pretty sure it's everywhere," says Francis.

After completing the first transatlantic study of marine plastic pollution in the southern hemisphere, researchers from Algalita and the 5Gyres Institute are due to arrive in Cape Town from Rio de Janeiro in December.

"We want to show people that the problem contaminates their international waters," says 5Gyres co-founder Marcus Eriksen. "They can't say, 'That's across the ocean, what does that have to do with my country?'"

A lot, apparently. While the Great Pacific Garbage Patch was discovered 13years ago, 2010 has been the red-letter year in which two more gargantuan stews of plastic confetti have been discovered swirling in the South Atlantic and Indian Ocean gyres. And, according to Francis, plastic confetti in the North Atlantic gyre has been studied since the 1980s, which means every single notable gyre in the ocean is now being gagged by plastic - including the South Pacific gyre, which the Algalita/5Gyres collaboration is planning to visit in March.

The Plastiki expedition, which was conceived by polar adventurer David de Rothschild as a nod to the Kon-Tiki voyage of 1947, set sail from California for Sydney in March to raise awareness of the ocean's garbage patches. Their vessel was an 18m catamaran made entirely from recycled plastic, including 12000 recycled plastic bottles.

"This stuff is ubiquitous - plastic has become as abundant as plankton," says Plastiki expedition director Matthew Grey. "For us the real story was the lack of wildlife in the open ocean. During the Kon-Tiki expedition, the crew had to bat sharks away. We didn't see a single shark. We fished for two months and caught three fish. It just felt like this barren wasteland infiltrated by plastic."

"The problem is much larger than anybody ever realised," Francis says. "This plastic is small - pieces of 5mm or less - and is dispersed throughout the ocean, so trying to clean it up is like sifting the Sahara with a little hand sifter." There's nothing for it, Francis says - all we can do is stop more plastic from getting out there.

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