Great Pacific Garbage Patch bigger than originally thought

Over 79 thousand tonnes of plastic is floating inside the Great Pacific Garbage Patch, 16 times higher than originally estimated, according to a study published in Scientific Reports.

The report examined a major ocean plastic accumulation zones between California and Hawaii called the Great Pacific Garbage Patch. Laurent Lebron and colleagues authored the study and found the amount of microplastics in the area were also rapidly accumulating, from 0.4 kilograms squared in the 1970s to 1.23 kilograms squared in 2015.

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According to the report, 99.9 per cent of all debris in this part of the ocean is made up of plastics. 46 per cent of this plastic is made up of fishing nets and three quarters of the debris was larger than 5 centimetres, including hard plastics and film.

Microplastics accounted for 8 per cent of the total mass of the plastics but made up 94 per cent of the estimated 1.8 trillion pieces floating in the area.

The researchers observed that common packaging plastics polyethylene and polypropylene were among some of the only types of debris thick enough to remain buoyant and remain in the zone.

While most of the larger items had broken down into fragments, researchers were able to identify containers, bottles, lids, packaging straps, and ropes. Some items in the test still had a readable production date, with one of the earliest being from 1977.

Aerial imaging and 652 net tows were used to capture the data. The differences between the estimates could be attributed to better technology allowing for a more accurate measurement, or an increasing level in ocean pollution in the areas following the 2011 Tohoku tsunami.

The report’s authors caution that more research is needed to quantify sources of ocean plastics in the Great Pacific Garbage Patch and to better assess how long plastics stay in the area.