Two Australian universities are part of a global effort launched on Saturday in San Francisco (early Sunday AEST) to remove an estimated 80,000 tonnes of plastic from the Pacific Ocean.
Nearly two trillion pieces of plastic – or about 250 pieces for every person on the planet – are currently floating in an area known as the Pacific Garbage Patch, and the situation is getting worse.
But the Ocean Cleanup Foundation hopes to turn the tide on this man-made mess.
Founded in 2013 by then 18-year-old Dutch inventor Boyan Slat, Ocean Cleanup wants to launch a fleet of floating garbage collection systems across the Pacific gyre – the huge circular current that keeps plastic trapped in the middle of the ocean.
Each system is made up of a 600-metre floating boom with a three-metre deep skirt that captures plastic for easier collection. The ocean’s currents, combined with the wind and waves, propel the boom towards the greatest concentration of debris.
Saturday’s launch saw the first boom, dubbed System 001, begin its long journey out of San Francisco Bay towards the Pacific Garbage Patch, 440 kilometres off the cost of California.
Dr Julia Reisser started volunteering for Ocean Cleanup in 2013 as a PhD candidate at the University of Western Australia. Her work on the depth at which most plastic floats formed an early part of proving the feasibility of the project.
“When I finished my PhD, [Boyan] invited me to join the Ocean Cleanup,” Dr Reisser said. She went on to lead two major scientific expeditions to quantify the amount of plastic in the Pacific Ocean before moving to Andrew Forrest’s Minderoo Foundation, where she continues to work on the eradication of ocean plastics.
Ocean Cleanup’s first expedition involved a fleet of 30 vessels crossing a 3.5-million-square- kilometre area of the Pacific to map plastic levels. According to the foundation, it was the largest ocean research expedition ever undertaken.
Marine researchers from Curtin University, led by Dr Chandra Salgado Kent, were later called in to participate in an aerial survey of plastics larger than 0.5 metres.
“The task was challenging given the large amount of debris that we needed to quantify,” Dr Salgado said. The amount of plastic shocked many observers who often struggled to enter data quickly enough before more plastic was spotted.
The expeditions found about 46 per cent of the mass of plastic in the Pacific Ocean is made up of large fishing nets and debris bundled together. Dr Reisser said fishing gear from as far away as Alaska and Malaysia formed huge masses weighing up to a tonne.
The launch of the first Ocean Cleanup system comes after 273 scale model tests, six at-sea prototypes and a comprehensive mapping of ocean plastics. Dr Reisser said she expected it would answer a lot of questions.
“The simulations that we’ve done on the computer suggest that it’s possible to remove half of the garbage patch. Now, it is time to test that in real life. It might be better than that, it might be worse,” she said.
“It’s worth trying. If we don’t try, we know that 100 per cent [of the plastic] is going to keep in the ocean.”
The foundation’s modelling suggested a fleet of about 60 garbage collection systems could clean up 50 per cent of Pacific Ocean plastic within five years, and when fully deployed across the other four ocean gyres could almost eradicate ocean plastic by 2050 when combined with land-based containment methods.
What comes next?
The foundation plans to recycle the majority of the plastic into products such as phones, glasses and furniture. The products would be branded as recycled by Ocean Cleanup and sold with the goal of making the foundation self-sustainable.