The North Pacific Subtropical Gyre circulates in a clockwise pattern and this tends to focus marine debris, particularly tiny plastic particles, into the center of the gyre. The Pacific Garbage Patch is said in the book World Ocean Census to be as large as Africa.
While it's easy to visualize a giant pile of plastic and other debris accumulated in the ocean, this isn't exactly what the Great Pacific Garbage Patch looks like. It looks more like a "soup" of tiny plastic particles and other marine debris. These particles float, but are not necessarily all gathered at the surface. Research on the plastic in the gyre usually involves taking samples using large plankton nets. These do a great job of straining out the water, leaving behind whatever organisms, or plastic, are in the ocean at that location.
Are There Other Garbage Patches?
The North Pacific Gyre is one of 5 major oceanic gyres. The other four are the South Pacific Subtropical Gyres, the North and South Atlantic Subtropical Gyres, and the Indian Ocean Subtropical Gyre. Increasingly, there is evidence that each gyre has its own garbage patch.
Garbage doesn't just collect in these gyres - debris can concentrate in other areas such as convergence zones, eddies, meanders and Langmuir circulation (surface currents usually caused by wind).
The North Pacific Subtropical Convergence Zone is an area identified as of high concern by NOAA because of its presence of "high productivity, pelagic species feeding and migration, and documented marine debris concentration." This area is a primary means of transport of marine debris onto the Hawaiian Islands.
What Can Be Done About the Great Pacific Garbage Patch?
Although various cleanup scenarios have been proposed, most researchers seem to agree that the only solution is prevention. Due to the widespread nature of the plastic particles and a cleanup operation's impact on marine life, we can't simply go out and scoop up all the debris. And it will continue to accumulate unless we stop using so much plastic, stop using so many disposable items and start disposing of our waste responsibly.