A new study says millions of tons of plastic garbage are flowing into the world's oceans, with much of it coming from mismanaged landfills and litter.
The report by international researchers estimates the amount of plastic garbage drifting into global waterways is far higher than earlier figures and will likely only continue to rise.
Kara Lavender Law, one of the report's authors, says the bulk of it comes from mismanaged landfill sites and dumps in developing countries where plastic usage is increasing without adequate waste management programs.
The research, published today in the journal Science, found that between 4.8 and 12.7 million metric tons of plastic entered the ocean in 2010.
A total of 275 million metric tons of plastic waste was generated in those 192 coastal countries.
The scientists say middle-income countries need to build the proper infrastructure to manage plastic waste and more prosperous countries need to reduce their consumption of plastic if the numbers are to come down.