Microplastics Threatening World's Oceans, Scientists Worry

Microplastics - microscopic particles of plastic debris - are possibly threatening the world's oceans, and scientists are growing more concerned due to their potential physical and toxicological risks to marine organisms, according to a new study.

In an article published Thursday in the journal Science, two scientists have called for urgent action to "turn off the tap" and divert plastic waste away from the marine environment.

These plastic bits are present in all five of the ocean's subtropical gyres, and have even been detected in Arctic sea ice. They have been found in organisms ranging in size from small invertebrates to large mammals, and are known to concentrate toxic chemicals already present in seawater - possibly harming marine life.

"Our scientific understanding of this environmental problem is accelerating rapidly, with many new research efforts that go well beyond simply documenting the presence of plastic in the ocean," lead author Professor Kara Lavender Law, of Sea Education Association in Massachusetts, said in a statement.

Most studies of ocean microplastic focus on the debris that floats at the sea surface, but this leaves other potential collections of plastic unaccounted for.

"Major unanswered questions remain about the amounts of microplastic debris that might be accumulating on the seafloor," said co-author Professor Thompson. "We also know very little about where, geographically, are the largest inputs of plastic to the marine environment."

A related study described in a recent Nature World News article notes that millions of tons of plastic end up in the ocean each day, but that lots of this debris cannot be found, and supposedly is ending up in some unknown sink.

Law and Thompson are urging the public to consider taking part in their "turn off the tap" initiative to reduce some of this plastic waste.

"By each of us making small changes in our daily habits - by carrying reusable water bottles and coffee mugs, for example - we can collectively reduce our dependence on 'disposable' items that might ultimately be lost to the environment," Law added.