8 million tons of plastic enter world's oceans each year: study

About 8 million tons of plastic waste wind up in the world's oceans every year, according to a study out Thursday that warned this amount could increase significantly in the next decade unless the international community improves its waste management practices.

Jenna Jambeck from the University of Georgia, along with colleagues from the United States and Australia, studied the sources of ocean-bound plastic around the world and developed models to estimate their annual contributions.

They suggested that coastal countries generated close to 275 million tons of plastic waste in 2010 and that 4.8 million to 12.7 million tons of that plastic made its way to the oceans.

Eight million tons, the midpoint of their estimate, "is equivalent to five grocery bags filled with plastic for every foot of coastline in the world," Jambeck said in a statement.

"This annual input increases each year, so ... in 2025, the annual input would be about twice the 2010 input, or 10 bags full of plastic per foot of coastline," she said.

The new study also identified the major sources of this ocean- bound plastic waste, listing the 20 countries, including China, Indonesia, India, Brazil, and the United States, that delivered the most plastic into the oceans that year.

According to the researchers' models, a country's population size and the quality of its waste management systems largely determine the amount of waste with the potential of reaching the oceans that it generates.

Nations around the world need to reduce waste and adopt better management strategies, such as expanded waste recovery systems, in order to prevent the amount of plastic debris in the world's oceans from increasing by a full order of magnitude over the next decade, they said.

"We need to make sure that we are collecting and capturing solid waste and plastic around the world," said Jambeck. "Second to this is what we do with it ... If we at least capture it, it's not going to go into the oceans."

The findings were published in the U.S. journal Science.