SAN FRANCISCO CHRONICLE
The plastic garbage pit of the Pacific Trash particles, looking like food, imperil sea life
Jane Kay, Chronicle Environment Writer
Monday, November 6, 2006
Plastic trash caught up in a swirling vortex in the North Pacific Ocean between California and Hawaii is killing sea life, choking birds and fish and entangling seals and sea lions, a new Greenpeace report says.
Soda six-pack rings, plastic bags, condoms, beach toys and stray nets -- much of it washed off U.S. shores and some tossed directly into the ocean -- float in a mix of plastic pollution that injures hungry animals as big as whales and as small as zooplankton, according to a report by the international environmental group.
Scientists traveling aboard the Greenpeace vessel Esperanza said Sunday they now are gathering firsthand data on threats to the world's oceans from pollution, overfishing and whaling. As part of that investigation, they released the report, a compilation of studies published since 1990 on plastics in the marine environment.
The current research examines plastic as it weathers into particles the size of sand grains, so small they become part of the tissue of ocean organisms.
"These small fragments of plastics may pose more of a threat to marine life because they resemble the prey of lots of organisms -- everything from zooplankton to whales,'' said Adam Walters, a chemist speaking by telephone aboard the vessel and an author of the report.
These bits can fill the stomachs of birds and other sea creatures that mistake them for food, causing malnutrition and eventually starvation. The researchers are measuring the distribution of the particles as they that float or fall to the ocean floor.
This latest report on plastic accumulating in the North Pacific comes just three days after a study in the journal Science concluded that, if trends continue, the world's fish stocks are headed for severe depletion by 2050 as a result of global warming, fishing and pollution.
The Esperanza, headed for San Diego, is conducting research in a Texas-sized patch of ocean called the North Pacific Gyre near the northwestern Hawaiian Islands. As winds and currents circulate clockwise in the oceans, this area stays calm in the summer and becomes a collection basin for plastics and other litter.
Over the past three decades, marine biologists have found plastic bags blocking the digestive tracts of sea lions, discarded fishing line strangling sea turtles and nets cutting off the flippers of manatees.
The research on micro-particles is new.
Since last March, scientists on the Esperanza have sampled plastic particles in the Mediterranean, North Atlantic, Red Sea, Indian Ocean and near the Philippines. Next come the Sea of Cortez and the South Pacific.
Thilo Maack, a marine biologist with Greenpeace in Hamburg, Germany, also speaking from the ship, said he has been diving for samples.
"Between the plankton, you see the red, yellow and all colored plastics floating. We find the plastic in the tissues of animals. For us, this is a very worrying signal,'' because it could be accumulating in the food web, Maack sad.
They often find "ghost nets,'' abandoned floating nets filled with fish.
"The marine mammals try to feed on these fishes, and get entangled in ropes and loose net parts. Eventually they drown because they can't get to the surface,'' Maack said.
The report, which doesn't contain the results of the research on micro-plastic, offers solutions.
Floating plastic debris can be cut worldwide by cleaning beaches, reducing garbage in storm drains, improving the handling and transport of raw pellet and other plastic materials, and adopting an international treaty prohibiting vessels from dumping trash at sea, according to the report.
The ultimate solution lies in policies that allow the use of plastics and synthetics only in cases where they are absolutely necessary, it said.
Other findings in the report compiled by Greenpeace are as follows:
-- At least 267 different species, including 111 species of seabirds, are known to have suffered from entanglement or ingestion of plastic rubbish.
-- Plastics consistently make up 60 to 80 percent of all marine debris. The seabed, particularly near coasts, is littered with plastic bags.
-- About 80 percent of the plastic in the ocean washes in from rivers, storm drains, beaches, sewage treatment plants and other sources; about 20 percent gets dumped in the ocean from vessels and fishing boats.
-- Much of the plastic litter in oceans comes from derelict fishing debris, since plastic and other synthetic materials have replaced natural fibers over the past 35 years.