1,000 particles of plastic per cubic metre of sea water in Atlantic Ocean

Measuring plastic in the oceans

The Atlantic Ocean contains 1,000 particles of plastic per cubic metre of sea water. These are the new findings of a new study to assess the amount of plastic in the oceans and it has been decided that the quantity is 10 times more than previously estimated. They were able to analyse seawater more accurately. Earlier research focused mainly on measuring plastic either on or near the surface or on the seabed. They missed the middle bit i.e. the water column. Also, some plastic sinks to the bottom because it is coated with bacteria. Earlier studies had used nets with a larger mesh size preventing them from detecting smaller particles which are more abundant.

Measuring plastic in the oceans

Measuring plastic in the oceans. Photo: NATIONAL OCEANOGRAPHY CENTRE

The new method to measure plastic incorporated a high-powered microscope to analyse the chemistry of samples to determine the nature of the plastic. The plastic particles were of polyethylene, polypropylene and polystyrene. These are the three most common plastics from human plastic waste which makes up more than half of global plastic pollution.

In all, the scientists estimated that in total there is 200 million tonnes of plastic in the Atlantic Ocean which has an average depth of 3,000 metres.

The study also concludes that rivers and storm drains in Southeast Asia and Africa are believed to account for most of the plastic in the ocean. There are other sources which includes ghost netting about which are written in the past. And also, there is plastic in the air (yes, it actually rains plastic sometimes). This plastic is blown from the land to the sea. Plastic is everywhere.

The size of the particles detected in this study ranged in size from about 30 microns to 0.5 millimetres. 30 microns is about half the width of a human hair. Richard Lampitt is a co-author of the study which is published in the journal Nature Communications.

He said that plastic plays an important role in our lives but it is being released into the environment because of poor waste management practices. Previous estimates of the amount of plastic in the Atlantic Ocean concluded that there was 17 million tonnes of it. This appears now to be have been a gross underestimate. My thanks to The Times newspaper for this story.