Thursday, February 07, 2008

Floating in Plastic Waste

The Pacific Ocean is home to a vast expanse of floating plastic trash.

The vast expanse of debris – in effect the world's largest rubbish dump – is held in place by swirling underwater currents. This drifting "soup" stretches from about 500 nautical miles off the Californian coast, across the northern Pacific, past Hawaii and almost as far as Japan.

Charles Moore, an American oceanographer who discovered the "Great Pacific Garbage Patch" or "trash vortex", believes that about 100 million tons of flotsam are circulating in the region. Marcus Eriksen, a research director of the US-based Algalita Marine Research Foundation, which Mr Moore founded, said yesterday: "The original idea that people had was that it was an island of plastic garbage that you could almost walk on. It is not quite like that. It is almost like a plastic soup. It is endless for an area that is maybe twice the size as continental United States."

Curtis Ebbesmeyer, an oceanographer and leading authority on flotsam, has tracked the build-up of plastics in the seas for more than 15 years and compares the trash vortex to a living entity: "It moves around like a big animal without a leash." When that animal comes close to land, as it does at the Hawaiian archipelago, the results are dramatic. "The garbage patch barfs, and you get a beach covered with this confetti of plastic," he added.

The "soup" is actually two linked areas, either side of the islands of Hawaii, known as the Western and Eastern Pacific Garbage Patches. About one-fifth of the junk – which includes everything from footballs and kayaks to Lego blocks and carrier bags – is thrown off ships or oil platforms. The rest comes from land....

Plastic is believed to constitute 90 per cent of all rubbish floating in the oceans. The UN Environment Programme estimated in 2006 that every square mile of ocean contains 46,000 pieces of floating plastic,

Dr Eriksen said the slowly rotating mass of rubbish-laden water poses a risk to human health, too. Hundreds of millions of tiny plastic pellets, or nurdles – the raw materials for the plastic industry – are lost or spilled every year, working their way into the sea. These pollutants act as chemical sponges attracting man-made chemicals such as hydrocarbons and the pesticide DDT. They then enter the food chain. "What goes into the ocean goes into these animals and onto your dinner plate. It's that simple," said Dr Eriksen.
Plastics in the ocean have terrible effects on seabirds and other organisms in all corners of ocean food webs.
Dutch scientists have found that more than nine out of 10 European fulmars – seabirds that eat at sea – die with plastic rubbish in their stomachs. A study of 560 fulmars from eight countries revealed they had ingested an average of 44 plastic items. The stomach of one fulmar that died in Belgium contained 1,603 separate scraps of plastic.

Birds are not the only ones to suffer. Turtles, whales, seals and sea lions have all eaten plastic. But the most sinister problem may be a hidden one at the other end of the food chain.

Small sand-hoppers, barnacles and lugworms have also been found to have ingested tiny fragments of plastic, some of which are thinner than a human hair. Apart from the physical damage these particles cause, they may also transfer toxic chemicals to creatures at the base of the marine food web.
The amount of plastic waste that collects in oceans (and on land) suggests an urgent need to reduce plastic consumption. Some localities have tried to attack the problem by reducing the use of disposable plastic shopping bags. San Francisco, for example, banned plastic bags (an example that Annapolis tried to follow). Other places, such as New York City, require that plastic bags be recycled by stores that provide them. Ireland has had success by imposing a steep tax on plastic grocery bags. Since imposition of the tax, plastic bag use declined by 94%. Some retailers, like Whole Foods, have tried to reduce or eliminate their own contribution to the pile. Unfortunately, reducing plastic consumption is easier said than done given the ubiquity of plastic products within our contemporary economy. Bags are a start, but larger changes will be necessary in the ways that plastic is used and disposed.