
North Pacific Gyre World Map by Fangz. Licensed under Public Domain via Wikimedia Commons.
North Pacific Gyre
The world's oceans are awash with nearly 269,000 tonnes of plastic waste, spreading pollution to the four corners of the Earth.
This is according to a study published on December 10th 2014 in open-access journal PLOS ONE by Marcus Eriksen from Five Gyres Institute, leading researcher of the Great Pacific Garbage Patch - the mass of rubbish that floats in the North Pacific Ocean at roughly 135-155 degrees west and 35-42 degrees north.
Microplastic pollution is found in varying concentrations throughout the five oceans of the world, but estimates of the global abundance and mass of floating plastics - both micro and macro - lack sufficient data to support them. In order to better estimate the total amount of plastic particles floating in the world's oceans, scientists from six countries contributed data from 24 expeditions collected over a six-year period from 2007-2013 across all five sub-tropical gyres, coastal Australia, the Mediterranean Sea and the Bay of Bengal.
The data collected included information about microplastics collected using nets and large plastic debris recorded from visual surveys. This information was then used to calibrate an ocean model of plastic distribution.
Based on the data, the study's authors estimate some 5.25 trillion plastic particles weighing at least 269,000 tonnes are floating in the world's oceans, with large plastucs appearing near coastlines, degrading into microplastics in the five subtropical gyres. The smallest microplastics were present in more remote regions such as subpolar gyres, which came as a surprise to researchers. The distribution of the smallest microplastics in remote regions of the ocean might indicate gyres shred large plastic items into microplastics, after which they are ejected across the ocean.
Eriksen, PhD, Director of Research for the 5 Gyres Institute, stated: "Our findings show that the garbage patches in the middle of the five subtropical gyres are not the final resting places for the world's floating plastic trash. The endgame for micro-plastic is interactions with entire ocean ecosystems."