( CNN ) -- It is a problem of massive plastic proportions -- a giant floating debris field , composed mostly of bits and pieces of plastic , in the northwest Pacific Ocean , about a thousand miles off the coast of California . Researchers recover nets from the Pacific Ocean on August 3 , 2009 . It 's called the Great Pacific Garbage Patch and it covers a vast area of hundreds , maybe even thousands , of miles of open ocean . Now researchers are trying to learn more about the sea-bound trash zone and perhaps find answers to basic questions . A crew of scientists from the University of California 's Scripps Institution of Oceanography has embarked on a three-week mission aboard the research vessel New Horizon , heading for the debris field to study it . The mission is not as straightforward as it sounds . `` There may be a misapprehension ... that if you got out there and stood on the middle of a deck you 'd see nothing but plastic litter from horizon to horizon , '' said Robert Knox , deputy director for research at the Scripps Institution . `` It 's relatively sparse , and you might or might not see something visible to the human eye at any particular location out there , '' Knox says . `` Certainly one does encounter pieces of plastic stuff that are big enough to see . But the other side of the puzzle is all the little bits and pieces of plastic that you ca n't even see unless you scoop up a sample of seawater and see what 's in there . '' `` I think it 's a little misleading to think of it as a great big island that you could practically get out and walk on , but the point is it 's a big area of ocean . So even a few pieces of plastic per square meter amounts to a lot of plastic when you add it up over this enormous ocean area . '' There has been some previous research on this garbage field , but not much . It 's been very poorly studied in a scientific sense . Major questions remain : . How how much stuff is there ? What size is the stuff ? Where is it distributed in the ocean , at the surface or at what depth ? What does it do to the food chain , especially the small particles of plastic that may be ingested by smaller organisms at the bottom of the food chain ? While the main focus of the Scripps mission is the impact of this plastic trash on marine life , researchers will gather information on a wide variety of issues . Here 's what scientists do know : They know the size of this zone is huge , maybe as big as Texas . And they know that all the plastic accumulated in the patch has mostly broken down into smaller bits , floating just under the water 's surface like confetti , basically a soupy mix of plastic-filled seawater that stretches for maybe thousands of miles . They know the garbage patch has been growing for many years , and scientists first became aware of the problem years ago when fisherman reported encountering widespread debris . They know there are other debris fields in other oceans of the world , but this one is the biggest . Rusty Brainard with the National Oceanic and Atmospheric Administration says this giant garbage patch , in addition to plastic , also contains huge masses of fishing nets , which destroys ecosystems around the Hawaiian Islands . But the plastic is really the toxic killer . While it slowly degrades , it turns into increasingly smaller bits of plastic . Seabirds mistake it for food and they dive down and eat it . Brainard says they find a lot of skeletons of seabirds on the Islands and `` their gut content is just filled with plastic . '' Brainard says that has scientists wondering what other animals are eating this plastic . As the larger animals and marine life eat the smaller animals , this plastic eventually ends up in the human food supply , too . But even the size is of the Great Pacific Garbage Patch is uncertain . `` It 's not a hard and fast number . It 's a little bit like a whirlpool on the surface of a river or a lake . You 'd be hard-pressed to tell me where the edge is . All you know is that it 's stronger in the middle than it is in the outer reaches . But it 's an area of many hundreds of miles -- perhaps thousands -- in which the ocean currents tend to bring it together , '' according to Knox . NOAA has tracked the Great Pacific Garbage Patch movement to some degree . Scientists know it moves as much as a thousand miles north and south in the Pacific seasonally . And during warmer ocean periods , known as El Nino , it drifts even further south . A kind of large , clock-wise circulation of currents driven by the wind around the Pacific ocean basin causes the plastic and other garbage to mix together in convergence zones , forming this giant trash zone and making its movements comparable to a whirlpool . Researchers believe this enormous trash zone accumulated over many years from trash being dumped off boats and ocean-going ships , and from trash accumulated on beaches , where it eventually washed in the Pacific Ocean and into the huge zone . This study mission may even help scientists determine whether there 's any way to clean up the Great Pacific Garbage Patch and , if so , the best way to do it . CNN 's Ninette Sosa contributed to this report .
Researchers are trying to learn the effects of the plastic and debris on wildlife . Experts from the Scripps Institution of Oceanography will spend three weeks at sea . Scientists say this sea-bound trash zone is largest among worldwide debris fields . Researchers believe this enormous trash zone accumulated over many years .