For several years, ocean researcher Charles Moore has been investigating a concentration of floating plastic debris in the North Pacific Gyre. He has reported concentrations of plastics on the order of 3.34 pieces per square meter with a mean mass of 5.1 milligrams per square meter collected using a manta trawl with a rectangular opening of 0.9m x 0.15m at the surface. Trawls at depths of 10m found less than half, consisting primarily of monofilament line fouled with diatoms and other plankton.
Estimates of the size of the patch vary from the size of Texas to twice as large as the continental United States. Researcher Dr. Marcus Eriksen believes the Great Pacific Garbage Patch is two areas of rubbish that are linked. Eriksen says the gyre stretches from about 500 nautical miles off the coast of California, across the Northern Pacific to near the coast of Japan.
The Independent newspaper stated that Moore estimates there are 100 million tons of flotsam in the North Pacific Gyre.
Much of the plastic is in very small pieces floating under the surface of the water, so capturing a photograph of the patch is not possible. Because the garbage is so small and scattered, clean-up is also incredibly difficult without endangering sea life.
One of the first researchers to study the Pacific gyre was oceanographer W. James Ingraham Jr. He developed the Ocean Surface Current Simulator (OSCURS) and predicts that objects trapped in the gyre may remain trapped there for sixteen years or more.
The floating particles also resemble zooplankton, which can lead to them being consumed by jellyfish, thus entering the ocean food chain. In samples taken from the gyre in 2001, the mass of plastic exceeded that of zooplankton (the dominant animal life in the area) by a factor of seven. Many of these long-lasting pieces end up in the stomachs of marine birds and animals, including sea turtles, and Black-footed Albatross. Besides ingestion and entanglement of wildlife, the floating debris absorbs toxins in the water which, when ingested, are mistaken by the animal brain for estradiol, causing hormone disruption in the affected wildlife.
There are many disturbing images on the web of the skeletal corpses of marine birds showing huge quantities of plastic items in what was once their stomachs causing their deaths
Links added by Big Soft Moose because the original was broken
The Great Pacific Garbage Patch
The science behind the mass of trash accumulating in the Pacific