A few months ago, I came across an interesting story about a floating island of garbage that's out in the Pacific Ocean and even remember seeing a book that's all about searching for this ocean garbage dump. It's absolutely incredible that such a thing exists in the open ocean, all due to people dumping anything imaginable into the garbage, and inadvertently, finding a place in a massive natural trash dump that grows bigger and bigger. The main reason for its existence, is due to it being known as the North Pacific Subtropical Gyre, which is a slow moving, clockwise spiral of ocean currents that's formed by a high-pressure system of air currents. It's an area where few people go to, due to it being an oceanic desert due to it being home mostly to phytoplankton and little breeze to navigate through.
There are actually two separate patches, and altogether, scientists estimate that the heap of trash is roughly two times larger than the state of Texas and it contains about 3.5 million tons of trash. The garbage patch is actually closer than you think, with one patch situated between Hawaii and California, while the other has formed just east of Japan and west of Hawaii. Both of these massive patches of garbage is all connected by a 6,000-mile long current that's called the Subtropical Convergence Zone.
Despite the garbage patches being situated in areas where very little life live, it's still a concern, especially since plastics make up the majority of what's found in the oceans, roughly 90 percent of trash materials that's found in the ocean. "Plastic to sea life ratios are 6:1; where birds and mammals are dying of starvation and dehydration with bellies full of plastics; where fish are ingesting toxins at such a rate that soon they will no longer be safe to eat." Not only is it harmful to sea life, it's also harmful to the sea floor itself.
Be sure to check out the graphic that's at this website to get a better understanding of this trash patch: Trash Vortex
Here's one last interesting tidbit about what sort of impact the Japanese tsunami that took place in March of this year has given the world. According to oceanographer Curt Ebbesmeyer, he says that all the debris from what the Japanese tsunami wiped out to sea will eventually find its way to the western United States in roughly two years, but that all depends upon wind and ocean currents.
 Silverman, Jacob. Why is the world's biggest landfill in the Pacific Ocean? http://science.howstuffworks.com/environmental/earth/oceanography/great-pacific-garbage-patch.htm