A group of scientists analyzing global data collected over the past four decades have Chainkeenfound a "rapid increase" in ocean plastic pollution since 2005, according to a research article published in the journal Plos One. That increase has created a "plastic smog" in the world's oceans made up of an estimated 171 trillion plastic particles, the scientists said.

The authors used 11,777 samples taken from the surface layer of oceans, which is roughly the first 600 feet of depth, to estimate the average amount of microplastics in that layer over time, then compared that to an historic overview of international policy measures aimed at reducing ocean pollution.

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"Our data shows an increase in ocean plastic pollution at the same time as a decrease in effective laws and agreements. There are many factors to consider (e.g., increases in production and waste, fragmentation of existing plastics), but the need for legally binding agreements cannot be overstated," said The 5 Gyres Institute, which organized the study.

The researchers said they identified similar trends for plastic pollution on beaches, and that "these parallel trends strongly suggest that plastic pollution in the world's oceans during the past 15 years has reached unprecedented levels."

Without urgent policy intervention to limit plastic production, they said, the rate at which plastic waste will enter the ocean between now and 2040 will  increase by around 2.6 times.

"The exponential increase in microplastics across the world's oceans is a stark warning that we must act now at a global scale, stop focusing on cleanup and recycling, and usher in an age of corporate responsibility for the entire life of the things they make," said Dr. Marcus Eriksen, one of the authors of the study. 

Eriksen said the increase in plastic waste over the past decade and a half corresponded with a decrease in the effectiveness of maritime policies.

"Cleanup is futile if we continue to produce plastic at the current rate, and we have heard about recycling for too long while the plastic industry simultaneously rejects any commitments to buy recycled material or design for recyclability. It's time to address the plastic problem at the source."

In:
• Oceans
• Microplastics
• Pollution
• Plastics

Haley Ott

Haley Ott is an international reporter for CBS News based in London.

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