MARINE DEBRIS - Marine Pollution: What Everyone Needs to Know - page 46

ending up in the middle of oceanic gyres (circular current
patterns) where currents are weakest. The ocean water is con-
stantly moving, carrying water, organisms, and debris around
the globe. As material is captured in the currents, wind-driven
surface currents gradually move floating debris toward the
center, trapping it in the region. Flotsam from San Francisco
can reach the North Pacific Gyre in as little as six months.
Crab trap tags and floats lost from the state of Oregon during
2006-2007 were recovered four years later in the Northwestern
Hawaiian Islands. The Great Pacific Garbage Patch is a vast
region of the North Pacific Ocean. Estimated to be double the
size of Texas, the area contains over 3 million tons of plastic,
mostly in small pieces. In this area waste material from across
the North Pacific, including coastal North America and Japan,
are drawn together. Contrary to what its name implies, the area
is not a concentration of trash visible in satellite or aerial pho-
tographs. There is not a giant island of solid garbage floating
in the Pacific. Rather, there are millions of small and micro-
scopic pieces of plastic floating over a roughly 5,000 square km
area of the Pacific. The amount has increased significantly over
the past 40 years, and plastic debris there apparently already
outweighs zooplankton by a factor of 36 to one. Islands within
the gyre frequently have their coastlines covered by litter that
washes ashore—prime examples being Midway and Hawaii,
where plankton tows sometimes come up with many more
plastic pieces than plankton. The next largest known marine
garbage patch is the North Atlantic Garbage Patch, estimated
to be some hundreds of kilometers across. There are other
smaller patches in the Southern Hemisphere.
Where else does debris accumulate?
Litter can end up anywhere. Not all of it floats; some of it is
heavy and sinks out of sight. Scientists at the Monterey Bay
Aquarium Research Institute (MBARI) analyzed 18,000 hours
of underwater video collected by remotely operated vehicles