A new international research project revealed the highest concentration of microplastic ever seen on the seafloor -- up to 1.9 million pieces in a thin layer covering one square meter.
More than 10 million tons of plastic waste enter the oceans each year, but that type of floating plastic -- think bags, straws or cellphone cases -- accounts for less than 1 percent of total plastic entering the world's oceans.
According to new research published this week in the journal Science, deep-sea ocean currents are acting as conveyor belts to move these extremely tiny plastic fragments and fibers across the seafloor. Microplastics, which are typically less than 5 milimeters in length, account for the other 99 percent.