When Sylvia Earle began diving in 1952, the ocean was pristine. These days, things are different.
“For the past 30 years I have never been on a dive anytime, anywhere, from the surface to 2-1/2 miles deep, without seeing a piece of trash,” says the renowned oceanographer and former chief scientist at the National Oceanic and Atmospheric Administration. “There’s life from the surface to the greatest depths – and there’s also trash from the surface to the greatest depths.”
Dr. Earle’s experience illustrates the rising tide of plastic accumulating in the world’s oceans.
And while the Pacific Ocean has garnered much attention for what some call the "Great Pacific Garbage Patch” – a vast expanse of floating plastic deposited in the middle of the ocean by circulating currents – the problem doesn’t stop there.
New research shows that plastic has collected in a region of the Atlantic as well, held hostage by converging currents, called gyres, to form a swirling “plastic soup.” And those fragments of plastic could also be present at the other three large gyres in the world’s oceans, says Kara Lavender Law, a member of the oceanography faculty at the Sea Education Association (SEA) in Woods Hole, Mass., which conducted the study.
Because the plastic has broken down into tiny pieces, it is virtually impossible to recover, meaning that it has essentially become a permanent part of the ecosystem. The full impact of its presence there – what happens if fish and other marine animals eat the plastic, which attracts toxins that could enter the food chain – is still unclear.
“It's a serious environmental problem from a lot of standpoints,” Dr. Law says. “There are impacts on the ecosystem from seabirds, fish, and turtles, down to microscopic plankton.”
The possible effect on humans is “a huge open question,” she adds. “If a marine organism were to ingest a contaminated plastic article, it could move up the food chain. But that is far from proven.”
The data collected by SEA, from 22 years of sailing through the North Atlantic and Caribbean, show a high concentration of plastic fragments centered about 30 degrees north latitude (in the western North Atlantic), says Law. That aligns with the ocean’s circular current pattern.
But don’t call this region the garbage patch of the Atlantic. Law, who has sailed through the plastic accumulation in the Pacific gyre as well, says the term “plastic soup” is more accurate for both areas. “There’s no large patch, no solid mass of material,” she says.
The idea of a garbage “patch” or “island” twice the size of Texas, a favorite term in the media for the now-infamous spot in the Pacific, feeds misconceptions, he says. “It’s much worse. If it were an island, we could go get it. But we can’t,” because it’s a “thin soup of plastic fragments.”
The plastic floating in the ocean comes mostly from land. Dumping plastic at sea has been prohibited by an international convention since 1988, but about 80 percent of the plastic in the ocean flows from rivers, is washed out from storm drains or sewage overflows, or is blown out to sea from shore by the wind.
According to the UN Environment Program, the world produces 225 million tons of plastic every year.
Law says that analyses of the density of the plastics picked up in SEA’s research show that much of it potentially comes from consumer items made of polyethylene and polypropylene plastics, which includes plastic shopping bags, milk jugs, detergent bottles, and other items “common in our everyday lives.”
Those post-consumer products eventually break down into small pieces – most of the fragments caught in SEA’s plankton nets are about the size of a pencil eraser. Fish, birds, and sea mammals can mistake those tiny pieces for food and eat them. Fish and birds caught in regions with high plastic concentrations have been found to have numerous bits of plastic in their stomachs.
One of the puzzling aspects of SEA’s study is that it does not show an increase in concentration of plastics during the 22 years of sampling.
“That’s one of the main questions we’re trying to answer with the data set,” says Law. “I believe the evidence shows there has to be more going into the ocean. The question is, why don’t we see an increase in this region where we collect.”
It’s possible that the plastics have broken down into such small pieces that they pass through the plankton nets, she says, or that bacteria or organisms growing on the pieces could cause them to sink. And some of the trash could escape to other areas of the ocean on wayward currents.
When it comes to stemming the tide of plastic waste, there is no easy answer. Most experts agree that cleaning up the tiny pieces already swirling in ocean currents thousands of miles from land is impossible. Instead, the focus should be on prevention.
Law says that education is key. It's important to raise awareness of what happens to the plastic that millions of people throw away every day. “There’s a perception that if you put it in a recycle bin, it will end up being recycled, but it’s not clear that’s always the case."
Perhaps, experts speculate, the real reason that so much plastic ends up at sea is because so much of it is designed to be used once, then tossed.
Dr. Eriksen says ending the throwaway design of plastics is essential to combating ocean pollution.
“I'm not against plastic, I'm just against the way we abuse the material,” he says. “Knowing the environmental consequences of it, we have to rethink the responsible use of it.”
Erickson also advocates economic incentives for plastic recovery – such as giving plastic products a return value in recycling centers – and “extended producer responsibility,” in which manufacturers are responsible for the life cycle of their products. That would force producers to build the cost of recovery or recycling into the cost of the product.