Eighteen years ago this summer, Capt. Charles Moore was sailing home aboard his 50-foot catamaran after the Transpacific Yacht Race from Los Angeles to Honolulu, and he discovered a plastic debris field in the North Pacific that was twice the size of Texas. It has since become known as the Great Pacific Garbage Patch.
“As I gazed from the deck at the surface of what ought to have been a pristine ocean, I was confronted, as far as the eye could see, with the sight of plastic,” Moore, the founder of the Algalita Marine Research Foundation, later wrote in an article for Natural History magazine. “It seemed unbelievable, but I never found a clear spot. In the week it took to cross the subtropical high, no matter what time of day I looked, plastic debris was floating everywhere — bottles, bottle caps, wrappers, fragments.”
This August, 50 vessels — at least a dozen of them sailboats returning from this year’s Transpac — will steer parallel courses across the North Pacific from Hawaii to California dragging small surface trawls called Mantas to collect plastic debris and record sightings of large plastic flotsam on smartphone apps. The Ocean Cleanup, an international grassroots organization (theoceancleanup.com) led by 21-year-old Dutch visionary Boyan Slat, says the project is designed to measure the amount and distribution of plastic in the Great Pacific Garbage Patch and will be the “largest ocean research expedition in history.”
It will cover 3.5 million square kilometers and set the stage for the rollout of Slat’s ambition to clean up the Garbage Patch and four others like it around the globe through the deployment of booms to capture the surface garbage and direct it to enormous storage bins so it can be recycled.
“When you want to clean the oceans, it is important to know how much plastic is out there,” Slat said earlier this year when he announced what the group calls the Mega Expedition. Estimates of the amount vary by several orders of magnitude. “The Mega Expedition will allow us to produce the first-ever high-resolution estimate of the amount of plastic inside the Great Pacific Garbage Patch,” he says.
In addition to the Transpac’s support, the effort has won the endorsement of Los Angeles Mayor Eric Garcetti, who has said, “It’s this type of creative and large-scale thinking that we need to tackle problems like this.”
“It’s a pretty ambitious program,” says Transpac spokesman Dobbs Davis. “The idea is to have people go through the Pacific High and get a readout of what’s out there.”
The Ocean Cleanup, which has raised more than $2 million from 38,000 people in 160 countries in a non-profit crowd-sourcing campaign, was offering voyagers as much as $10,000 per boat to offset some of the costs of making the 2,500-mile voyage.
Dobbs says many Transpac racers know about the Garbage Patch firsthand, especially after the March 2011 Japanese tsunami dumped more than 1 million tons of garbage into the Pacific and the North Pacific Gyre.
Typically the Transpac fleet, which numbered 66 registrants this year, sails along the lower edge of the high — below the Garbage Patch — to catch prevailing easterlies that carry the boats to Hawaii. Coming back, the boats often turn north into the high, where the winds are light, to avoid headwinds, and it’s there that they encounter the ocean of plastic. “You head due north and take a right,” Dobbs says. “You bring lots of fuel, you bring your lawn chair, and you bring lots of CDs.” It’s slow going, and the garbage is everywhere.
Joel Young’s Beneteau 523, Transformer, will be one of the Transpac boats joining the Mega Expedition. Bob Solliday, Transformer’s delivery skipper from Hawaii to the West Coast, and his crew will collect plastic debris while reporting back to the American Sailing Association, a sail-training group, on what they are finding. Based on those reports, ASA plans to provide exclusive documentary-style content from the Garbage Patch at its website (asa.com/themegaexpedition). “We’re all sailors, and we love the ocean,” says Solliday of his motivation to be part of the expedition. “We all understand that the health of the ocean directly affects every living thing on the planet.”
The North Pacific Gyre’s wind-driven currents — the North Equatorial, Kuroshiro, North Pacific and California — flow clockwise, gathering pollution, including non-biodegradable plastics, and slowly spinning the trash to the center of the high, where the air is light and chemicals and debris become trapped in the calm waters. An estimated 8 million tons of plastic are dumped into the ocean each year, much of it accumulating in the North Pacific Gyre and four others in the South Atlantic, Indian, North Atlantic and South Pacific. Scientists estimate that 5.25 trillion pieces of plastic are in the oceans, a third of that concentrated in the Great Pacific Garbage Patch and much of it “nano-plastics” — plastic garbage ground into particles.
The Ocean Cleanup estimates it would take 79,000 years and tens of billions of dollars to collect the plastic from just one garbage patch using vessels and nets, the most obvious method. Challenging the conventional wisdom that the only feasible response to plastics in the ocean is to stop dumping them there and, wherever possible, to stop using them, Slat — while endorsing those measures as part of the solution — has proposed a passive system for removing plastics from the ocean by setting out a 100-kilometer array of booms in the garbage-collecting gyres.
The booms extend 2 to 3 meters deep in the water column and cross the gyre’s current in two 50-kilometer legs fixed at an obtuse angle to each other by deep ocean anchors and moorings that allow the booms to ride waves as large as 5.5 meters. If the waves exceed that, the booms decouple on one side and orient themselves to the direction of the seas to keep from breaking apart.
As the current flows beneath the array, the booms capture plastics in the top 2 to 3 meters of the gyre, where 80 percent of the plastics in the top 5 meters lies. The current slowly moves the captured debris down the length of the booms to the center of the array — its vertex — where small debris is pumped into a large storage bin and separated from the water, using centrifugal force, and large debris is scooped and deposited into the bin using a mesh conveyor. A vessel empties the bin every six weeks or so, and the plastics are transported to shore for conversion to oil.
Slat and a team of 100 volunteer scientists, engineers and economists have compiled a 500-page feasibility study showing that passive cleanup can work. They estimate it will take three to six years for the water in a gyre to complete a rotation through the boom; they plan to keep an array in place in the Great Pacific Garbage Patch for 10 years, long enough to clean up 42 percent of the plastics there — about 70,320,000 kilograms. Estimated cost of the cleanup: $5 a kilogram.
The Ocean Cleanup says its focus for this year and next is the Mega Expedition, and the design and deployment of the first operational plastics cleanup array — 2,000 meters long — off Japan’s Tsushima Island, where currents passing through the Tsushima Strait deposit 30,000 square meters of trash onto the island’s shores each year. The city government of Tsushima now manually cleans up the trash at a cost of $5 million a year. Target date for deploying a 100-kilometer array in the Garbage Patch is 2017.
“Human history is basically a list of things that couldn’t be done — but then were done,” says Slat, speaking about The Ocean Cleanup last year in New York City. He believes he and his team are ready to do the impossible: retrieve a big chunk of the plastic that we have indiscriminately dumped into the world’s oceans.
This article originally appeared in the September 2015 issue.
