Posted on | August 27, 2010 | Comments Off
Twenty-two years worth of data collected by undergraduate students aboard a sailing vessel has identified widespread floating plastic debris in the western North Atlantic that is comparable to the Great Pacific Garbage Patch. The study, led by a team of researchers from Mānoa, Sea Education Association and Woods Hole Oceanographic Institution, was published in Science Express.
UH Mānoa Senior Researcher Nikolai Maximenko, a co-author on the paper, developed a computer model that describes how converging surface currents cause the plastic to accumulate in such garbage patches.
Students of SEA collected samples of plastic in surface plankton nets at 6,100 locations over 22 years. The highest concentrations of plastic they found in a region of the North Atlantic predicted by Maximenko’s model, around 32°N (roughly the latitude of Atlanta, GA).
“The study is so exciting because it validates the computer model we’ve developed using more than 15,000 trajectories of drifting buoys,” says Maximenko. “The purpose of the model is to track long-living objects that float on the ocean surface. Our model has already successfully reproduced the location of the Great Pacific Garbage Patch. That now the debris in the North Atlantic collects mostly where our model predicts is further evidence that plastic moves in a similar way that drifters do. We can now expect that our model will be very useful in coordinating debris detection and clean up operations.”
“Not only does this important data set provide the first rigorous scientific estimate of the extent and amount of floating plastic at an ocean-basin scale, but the data also confirm that basic ocean physics explains why the plastic accumulates in this region so far from shore,“ says lead author and SEA scientist Kara Lavender Law.
Maximenko’s model predicts three other ocean garbage patches that have yet to be found—one in the South Atlantic, one in the South Pacific, and one in the South Indian Ocean. These patches are in regions that ships rarely visit.