Plastic debris widespread on ocean surface
NEW YORK — Plastic junk is floating widely on the world's oceans, but there's less of it than expected, a study says.
Such ocean pollution has drawn attention in recent years because of its potential harm to fish and other wildlife.
The new work drew on results from an around-the-world cruise by a research ship that towed a mesh net at 141 sites, as well as other studies. Researchers estimated the total amount of floating plastic debris in the open ocean at 7,000 to 35,000 tons.
Andres Cozar of the University of Cadiz in Spain, an author of the study, said that's a lot less than the 1 million tons he had extrapolated from data reaching back to the 1970s.
The new estimate includes only floating debris, not plastic that may reside beneath the surface or on the ocean floor.
Of the plastic pieces caught by the ship's net, most were less than about a fifth of an inch long. Some floating pieces start out small, like the microbeads found in some toothpastes and cosmetics or industrial pellets used to make plastic products. Other small pieces can result when wave action breaks up larger objects such as bottle caps, detergent bottles and shopping bags.
The net turned up fewer small pieces than expected, and it will be important to figure out why, researchers said. Perhaps the tiniest pieces are being eaten by small fish, with uncertain effects on their health, Cozar said in an email.
While the research showed plastic to be distributed widely, concentrations were highest in five areas that were predicted by ocean current patterns. They are west of the United States, between the United States and Africa, west of southern South America and east and west of the southern tip of Africa.
Plastic debris from land reaches the ocean mostly through storm water runoff, the researchers said in their report, released on Monday by the Proceedings of the National Academy of Sciences.
Kara Lavender Law, who studies plastic pollution at the Sea Education Association in Woods Hole, Mass., said the study provides the first global estimate she knows of for floating plastic debris. The estimate appears to be in the ballpark, given the results of previous regional studies, said Law, who didn't participate in the new work.
“We are putting, certainly by any estimate, a large amount of a synthetic material into a natural environment,” Law said. “We're fundamentally changing the composition of the ocean.”
The impact on fish and birds is hard to gauge because scientists don't understand things like how much plastic animals encounter and how they might be harmed if they swallow it, she said.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Half Moon Bay contest dubs 1,969-pound pumpkin the plumpest
- Supreme Court to consider reprieve for teens who kill
- Stocks up before earnings reports
- House’s Flores will seek speakership if Ryan doesn’t
- Army budget cuts stretch forces thin, threaten readiness, secretary says during conference
- Sagging inflation expected to rule out Social Security cost-of-living adjustment
- Part of major highway reopens as South Carolina recovers from floods
- El Niño storms might not be savior for Calif.
- Dell buying EMC in a transaction valued at about $67 billion
- Lawmaker seeks ban on LGBT ‘conversion therapy’ in New Hampshire
- Tennessee bill seeks to curtail teaching of ‘religious doctrine’