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Our plastics will pollute oceans for hundreds of years

10 January, 2013

Australia’s plastic garbage has made its way into every ocean in the world. New research shows that it doesn’t matter where in the world plastic garbage enters the ocean, it can end up in any of the five ocean basins.

The research also showed that, globally, humans have put so much plastic into our planet’s oceans that even if everyone in the world stopped putting garbage in the ocean today, giant garbage patches would continue to grow for hundreds of years.

These were just two startling results from an investigation by researchers at the Australian Research Council Centre of Excellence for Climate System Science, based at UNSW, that looked at how these giant ocean garbage patches, some the size of NSW, form as a result of ocean currents.

"There are five known garbage patches in the subtropical oceans between each of the continents. Each contains so much plastic that if you were to drag a net through these areas you would pull up more plastic than biomass," lead author Erik Van Sebille, who is a Research Fellow at the Centre, said. 

"Interestingly, our research suggests a smaller sixth garbage patch may form within the Arctic Circle in the Barents Sea, although we don’t expect that to appear for another 50 years."

Another result showed, for the first time, that giant oceanic eddies, some up to 50km across, actually helped shift plastics between garbage patches that were thousands of miles apart and in entirely different oceans.

If you were to drop a rubber ducky in the ocean, or 28,800 floating toys as happened in 1992, it could end up in any ocean in the world according to this research.

"This means that garbage from any country can end up in any one of these garbage patches. This tells us that no single country is responsible. Ocean garbage is an international problem that requires an international solution," Dr Van Sebille said.

To achieve their results, the researchers used data from drifter buoys, which are part of the Global Drifter Program, to determine the movement of surface ocean currents. The program releases hundreds of drifter buoys into the ocean every year.

Each buoy floats around the ocean sending out regular 140 character messages on its location and the ocean conditions it’s experiencing. Dr Van Sebille describes it as being like Twitter from the ocean.

The data gathered by these buoys was then used to determine how garbage, and plastics in particular, moved around the ocean. The garbage eventually found its way to areas where ocean currents and winds converged, known as gyres. It was here that the massive garbage patches formed.

"If you sail through these areas you will not see big lumps of plastics or rubber duckies or things like that. The sun and interaction with the ocean breaks the plastics down into very small pellets that are almost invisible to the naked eye." Dr Van Sebille said.

"However, these plastics even at this small size do affect ecosystems - fish and albatross swallow these plastics while phytoplankton can use the floating pellets to stay buoyant and float near the surface where they grow best.

"Plastic is also the canary in the coal mine: poisonous chemicals, that are much more hazardous to the ecology, ride the currents in the same way and are actually absorbed by the plastic pellets."

In the next stage of his research, Dr Van Sebille wants to examine what happens to plastics closer to the coast.

"Clearly, by the amount of plastic found on beaches not all of it ends up in the gyres to form garbage patches in the deep ocean. We need to find out what happens to the plastics closer to land, where most fishing occurs, and what effect that has on the environment around our coasts," he said.

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Matt | Wednesday, January 16, 2013, 10:52 AM
Great article.I own a plastics recycling company and have been involved in plastic recycling for 25 years. Because of higer pricing from the carbon tax it is becoming uneconomical to do any more. Last year I recycled 100000 ton. Not sure which ocean that will go to when I close..
jane caldwell | Thursday, January 17, 2013, 11:32 AM
I was completely gob smacked when I became aware of the garbage gyres, how they are formed and impact on the waters and all living matter in the oceans. Do scientists believe it is possible to remove these patches from the oceans? What is the current long term prediction for the garbage gyres? Jane Caldwell
Johnny | Thursday, January 17, 2013, 2:15 PM
Matt, I do PP extrusion. Do you think I can find a reliable recycler in WA? After 2 years of trying out different guys, nobody seems interested in recycling. Anybody speaking of "plastics" has me worried. If exposed to the environment, most "plastics" will break down to the single monomer building block, which is not visible to the naked eye. PP will eventually break down to carbon and hydrogen.
Maurie Gill | Friday, January 18, 2013, 11:34 AM
I have sailed the Pacific Ocean and never seen any plastic. I'm in the plastic industrand our bigest problem is getting plastics to last
Katherine | Thursday, January 31, 2013, 1:08 PM
Don't you people read anything or watch TV? There was a documentary on SBS last month about the amount of plastic in the oceans and its effect on marine life. Apparently, fish eat so much of this stuff that eating fish meat has become dangerous for humans. Bon appetite!
Mike Turner | Thursday, January 31, 2013, 1:46 PM
Matt, if you contact me (www.envorinex.com) I may be able to offer some recycling avenues for your consideration. The issue of using the term 'plastics' infers that all the plastic gyre material is of the same genre which is not so. Different plastics have different specific gravity weights or values and will therefore either float or sink. Interestingly PVC is made from 57% sodium chloride (commonly know as sea salt) and is therefore a sustainable recycling medium.
Russell | Thursday, January 31, 2013, 7:53 PM
Working with some plastics manufacturers their swarf and waste goes everywhere and no one gives a toss. It blows outside and all around including into storm drains. Agree with Johnny's comments and the general public also need to stop littering. Heavy fines should be imposed like in Singapore for those dropping litter or letting it fly off their vehicles for example.