Located hundreds of miles off the coast of North America -- between 22 and 38 degrees north latitude, or about the distance from Cuba to Virginia -- the patch poses health risks to fish, seabirds and marine animals.
Like the infamous Great Pacific Garbage Patch, debris can circulate for years, accumulating as the result of ocean currents.
The patch was found by student researchers participating in the Sea Education Association's semester academic program, who over 22 years deployed thousands of fine-meshed plankton nets in the area to discover the makeup of the patch.
They found that most of the debris is comprised of tiny pieces of trash -- each "less than a tenth the weight of a paper clip," according to National Geographic --that came from consumer product litter either blown off open landfills or directly disposed of in the ocean.
Students found some areas as dense as 520,000 bits per square mile, or approximately 200,000 bits per square kilometer.
In comparison, spots of the Great Pacific Garbage Patch have been found to be as dense as 1.9 million bits per square mile, or approximately 750,000 bits of plastic per square kilometer (and several tens of feet below the surface).
SEA oceanographer Kara Lavender Law revealed the discovery on February 23 at the American Geophysical Union's 2010 Ocean Sciences meeting in Portland, Oregon.