Study finds less plastic than expected in world’s oceans

Nature : At least 5.25 trillion plastic pieces, weighing some 268 940 tons, are currently floating in the world’s oceans, according to a recent study by Marcus Eriksen of the Five Gyres Institute in Los Angeles and his colleagues. Although that sounds like a lot, it represents just 1% of total annual global plastic production. Furthermore, three-fourths of the total mass of plastic consists of pieces larger than 200 mm across. Because larger pieces tend to break up into smaller ones, researchers had assumed they would find evidence of much more microplastic. To explain the small proportion of microplastic found, the researchers propose that either the pieces are so small they slip through the sampling nets, or they get washed ashore, sink to the deep sea floor, or somehow degrade or are eaten and digested by seals or other animals. The researchers say further study is needed to determine where the plastic is going and to understand the many processes involved.