Wednesday, January 12, 2011
I'm all for a clean environment, but has another eco-nazi myth been busted?
By Emily Sohn
Setting the record straight about what's out there is key to regaining the trust of a wary public, White said. In 2008, she joined an expedition with the Center for Microbial Oceanography: Research and Education. It was a boat trip from Hawaii to California, through the heart of the Great Pacific Garbage Patch.
"None of us on that cruise had been to the patch, but we had all heard that it's twice the size of Texas. That's in a textbook," she said. "These statements are so frequent and in so many places that they are accepted as fact. But they undermine the credibility of those advocating for reduction of plastic pollution in the terrestrial and marine environments."
"Plastic is everywhere," and it's insidious, she said. "But it's not a patch."
White's main goal on the research cruise was to look at relationships between plastic and marine microbes. Along with experiments on microbial respiration and productivity rates, she and colleagues tediously counted and sorted pieces of plastic that were caught in nets towed behind the boat.
When the scientists extrapolated their results into estimates of how much plastic is swirling in ocean gyres, their numbers were just about the same as what other studies have found. But those numbers don't match up with the imagery often described in the media, White said. She has presented her findings to other experts and is preparing a paper for publication.
"You might see a piece of Styrofoam or a bit of fishing line float by at random intervals after hours or 20 minutes, but greater than 90 percent of the plastic was less than 10 millimeters in diameter," she said. "If you filled a thousand Nalgene water bottles in the North Pacific, three to five would have one piece of plastic in them the size of an eraser."
On an expedition through the garbage patch last summer with the Sea Education Association and the Woods Hole Oceanographic Institution, author and biogeographer David M. Lawrence noticed a similar pattern. Most of the plastic their boat picked up was tiny, widely dispersed and invisible to the naked eye.
"I was under the impression that you had these big conglomerations that were like Empire State buildings-tall," said Lawrence, who's based in Mechanicsville, Va., and was not surprised by White's analysis. "But that's not what it's like."
Even as the garbage patch fails to live up to the hype of a floating continent, Lawrence added, the truth might actually be worse and far more insidious. Compared to a big mound of trash, for one thing, it's impossible to clean up tons of tiny and widespread specks of plastic. You can't just scoop them up.
Without a dramatic metaphor expressed in "units Texas," White said, it also becomes more challenging to define the extent of the problem to the public. Even scientists still don't know how deep the plastic goes or how much of it is now sitting on the seafloor.
Still, small bits of plastic pose a variety of threats to the environment. They often end up inside fish and can work their way up the food chain. And plastics that are exposed to the elements release chemicals as they break down -- all with unknown but worrisome consequences for animals, water quality and human health.
"There is no reason to have plastic in the marine environment," White said. "But I think we undermine the issue by overstating the results. It's like crying wolf. That's the danger."