I first heard about the Great Pacific Trash Vortex on the Rachel Maddow show a few weeks ago. Rachel read about it in a San Francisco Chronicle article from October 19th, 2007. And they were running with a story that is about a year old and was publicized by Greenpeace following their report entitled "Plastic Debris in the World's Oceans." Apparently, there is a pile of trash twice the size of Texas floating in the Pacific ocean, and I feel like I must have been living on the Moon not to have heard of this sooner.
So what exactly is going on?
A set of four currents in the northern Pacific creates a clockwise vortex known as the North Pacific Gyre, which encompasses 10 million square miles, or basically the entire northern part of the ocean. For the purposes of this discussion I have also included an image generated by Greenpeace, which shows the two trouble areas: the Western Garbage Patch near Japan and the Eastern Garbage Patch between Hawaii and California. The Subtropical Convergence Zone, a 6000 mile current that connects the two patches is equally loaded with refuse and has been the center of some recent marine research.
Although it is not a solid island of trash, as the SF Chronicle suggests, this area of the ocean is littered with plastic flotsam. The UN Environment Program estimates that 46,000 pieces of plastic litter are floating on every square mile of the oceans. Captain Charles Moore, founder of the Algalita Marine Research Foundation, has come up with the estimation that the the Trash Vortex contains concentrations of plastics on the order of 3.3 million pieces per square km, with an average weight of 5.1 kg of plastic per square km of ocean.
Plastics are notoriously durable, degrading only in the sunlight and even then slowly and incompletely. They contain DDT and PCBs, and are of great danger to marine life. Fish, jellyfish and other underwater creatures consume the degrading plastic, which mimics and outnumbers their foodstuffs (plankton etc). Birds and larger animals consume larger plastic products mistaking them for fish. A study of the albatross at the Midway Atoll, a seabird rookery between Japan and Hawaii, found that of the 500,000 chicks born each year, 200,000 die of starvation and dehydration, their stomachs filled with plastics. 5 tons of plastic are fed by the parent albatross to their young each year at the atoll alone.
Hawaii is not faring any better. The Gyre currents wash out tons of plastic trash onto it's many beaches, covering them with piles several feet tall or even worse, plastic sand which is impossible to clean. 80% of this trash originates on land and is carried through sewers and rivers to the ocean, only to be trapped in the gyre or to be washed ashore elsewhere. Clean up of the Pacific is unlikely. The area is too large, and trawling the ocean may be even more disruptive to the marine life. While clean ups of Hawaiian beaches are underway, and some efforts are being made to capture the trash from rivers (such as the LA river pictured here) before it enters the ocean, the only sure fire way to decrease the growing Vortex is to reduce our use of plastic waste. An average American is estimated to use about 300 pounds of plastic every year. On land, it will take decades, if not centuries for petroleum-based plastics to degrade into carbon dioxide and water, but in the water, where the temperature is low and sunlight blocked out by algal growth, the process will take much longer. Some starch-based 'biodegradable' plastics are currently in production, but these also require land conditions and time to decompose. Recycling is always a good practice but unlike paper and organic waste it is harder to transport and reuse plastics, due to the differences in make up and previous use. Certainly I would encourage everyone to reduce their plastic waste, but at the moment, my outlook on our planet's future is pessimistic.
As a side note, Australian artist Helle Jorgensen is currently working on a project called the Rubbish Vortex, in which she will crochet a creation from plastic bags. Helle also participated in the crochet coral reef, a collaboration of many artists and IFF, which was exhibited in Chicago. Helle's work is beautiful and meaningful at the same time, and brings a little ray of light into my gloomy day.
Update 8-5-2009: CNN is running a story abou the vortex today. Check it out here.