*Perilous Times
Scientists study huge floating ocean garbage patch*
By Steve Gorman in Los Angeles, USA
Reuters
August 04, 2009 12:59pm
MARINE scientists from California are venturing to the middle of the
North Pacific for a study of plastic debris accumulating across hundreds
of kilometres of open sea dubbed the "Great Pacific Garbage Patch".
A research vessel carrying a team of about 30 researchers, technicians
and crew members embarked on Sunday on a three-week voyage from the
Scripps Institution of Oceanography, based at the University of
California at San Diego.
The expedition will study how much debris - mostly tiny plastic
fragments - is collecting in an expanse of sea known as the North
Pacific Ocean Gyre, how that material is distributed and how it affects
marine life.
The debris ends up concentrated by circular, clockwise ocean currents
within an oblong-shaped "convergence zone" hundreds of kilometres across
from end to end near the Hawaiian Islands, about midway between Japan
and the west coast of the US.
The focus of the study will be on plankton, other microorganisms, small
fish and birds.
"The concern is what kind of impact those plastic bits are having on the
small critters on the low end of the ocean food chain," Bob Knox, deputy
director of research at Scripps, said after the ship had spent its first
full day at sea.
The 170-foot (52 meters) vessel New Horizon is equipped with a
laboratory for on-board research, but scientists also will bring back
samples for further study.
Little is known about the exact size and scope of the vast debris field
discovered some years ago by fishermen and others in the North Pacific.
Large items readily visible from the deck of a boat are few and far
between. Most of the debris consists of small plastic particles
suspended at or just below the water surface, making it impossible to
detect by aircraft or satellite images.
The debris zone shifts by as much as 1600 kilometres north and south on
a seasonal basis, and drifts even farther south during periods of
warmer-than-normal ocean temperatures known as El Nino, according to
information from the National Oceanic and Atmospheric Administration (NOAA).
Besides the potential harm to sea life caused by ingesting bits of
plastic, the expedition team will look at whether the particles could
carry other pollutants, such as pesticides, far out to sea, and whether
tiny organisms attached to the debris could be transported to distant
regions and thus become invasive species.
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