How much plastic do rivers dump into the world’s oceans? The Ocean Cleanup decided to find out. They conducted what they say is the “first-ever estimate of plastic emissions from rivers” and the results are shocking, as in, between 1.15 and 2.41 million metric tons annually shocking. They say knowing the trash’s origins will help them better deploy their plastic-scooping cleanup arrays.
Scientists have known for a long time rivers deposit plastic into oceans, but before this study no one had ever quantified just how much plastic is flowing from rivers, or how much each river contributes, according to The Ocean Cleanup. To answer such questions, researcher Laurent Lebreton of The Ocean Cleanup designed a model drawing from data on waste management, population density, dam locations, hydrography, and topography.
The researchers found out of 40,760 rivers, a mere 20 contribute two thirds of the plastic input. The plastic also enters oceans more heavily between May and October: three quarters of plastic released makes its way into ocean waters then.
The Ocean Cleanup created an interactive map to help visualize the issue. The map tells a user how many kilograms of plastic have entered the oceans just since they started viewing it. You can check it out here.
The Ocean Cleanup founder and CEO Boyan Slat said in a statement, “We’re pleased to see how many initiatives have been taken in the past few years to raise awareness of the ocean pollution problem. However, for our work in the deep ocean to succeed in the long run, it’s crucial that governments and other organizations speed up their efforts to mitigate the sources of the problem we aim to resolve. The results of this latest study can assist with those efforts.”
The journal Nature Communications published the study online today. Four Ocean Cleanup researchers were joined by one scientist from North Carolina State University and an expert from HKV Consultants in the Netherlands.
Images via The Ocean Cleanup