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What is likely the world’s newest beach is already threaded with microplastics.
The beach at Pohoiki in Lower Puna, was created last year by the eruption of the Kilauea volcano.
When lava enters the ocean, its leading edge shatters explosively, like red-hot glass suddenly dowsed with cold water. The resulting black sand — tiny fragments of volcanic basalt — washed ashore again at Pohoiki and other places along the Puna Coast. At Pohoiki, it accumulated so thickly that it created a whole new beach, reshaping the coastline and cutting off a former boat ramp there.
But the waves have also brought something else ashore: millions of tiny bits of plastic, ranging from the size of an eraser to particles smaller than grains of sand.
They were discovered by Nic Vanderzyl, who just graduated from the University of Hawaii Hilo’s Marine Sciences Program.
For a year-long senior thesis project, Vanderzyl examined microplastics at three Big Island Beaches: Hapuna Beach State Park, perhaps the island’s most popular tourist beach; the beach along Hilo Bay, an urban environment that has approximately 45,000 people living nearby but is partially walled off from ocean currents by its long breakwater; and the new beach at Pohoiki.
The study of them is so new that Vanderzyl had to invent his own device for separating microplastics from sand. The device, made from PVC plastic and based on the fact that microplastics had a lighter relative density than basalt sand and other sediments, allowed him to measure how much plastic was in each small sample.
Of the three beaches Vanderzyl studied, Hapuna had the highest rate of microplastics, an average of about 70 bits per 50 grams (roughly a handful) of sand. Hilo Bay had about 52. The new beach at Pohoiki had 20 bits of plastic per 50 grams.
Another surprise was the types of plastic he found. Vanderzyl divided them into three categories: “nurdles,” grains of raw plastic that would have been processed into consumer products; “fragments,” bits of plastic from sources such as cups and bags broken down over time; and “fibers,” bits of products such as fishnets or polyester clothing.
At Pohoiki, Vanderzyl found that most of the microplastic pollution consisted of fibers.
“One garment can shed more than 1,900 particles per wash,” said Vanderzyl, who wore cotton clothing while he worked so he wouldn’t contaminate his samples. He thinks washing machines should be equipped with lint catchers like those in dryers.
Vanderzyl’s project represents the first marine science conducted at the new beach, according to his faculty advisor, Steve Colbert.
The work is important, Colbert said, because these particles of plastic are so small that they can “end up affecting the smallest parts of our food web. Zooplankton and the smallest fish can eat those things, and it’s really not known what the effect is on the base of the food chain.”
Other students in the UH Hilo program, he said, “have exposed coral polyps to bits of plastic, to see if they would mistake them for zooplankton and consume them, and they did.”
Zooplankton are organisms such as single-celled animals and the eggs and larvae of fish and crustaceans that drift on ocean currents. Along with phytoplankton, their plant equivalents, they form the “food supply upon which almost all oceanic organisms are ultimately dependent,” according to Britannica Online.
Even baleen whales eat them by the ton — along with drifting plastic and any plastic that the zooplankton have eaten — which may mean that as the microplastics move up the food chain they can accumulate in greater concentrations.
And they may affect ocean life in other, unexpected ways. Vanderzyl said, for instance, that microplastics heat at different rates than regular sand.
“Microplastics hold heat at the surface instead of allowing it to penetrate the sediment column,” he said, adding that other studies have demonstrated that the temperature of sand around turtle eggs determine which sex they become.
“Microplastics are super-understudied,” Vanderzyl said. “There’s a lot that’s not known.”
His research has already gotten him a job as an environmental educator with the Hawaii Wildlife Fund. He volunteered with the organization last year on another microplastics project: a group of engineering students from Université de Sherbrooke in Quebec had built a 9-foot-tall prototype machine that operated on similar principles to Vanderzyl’s testing device and could, they hoped, be used to actually clean plastics out of sand on heavily polluted beaches.
They’d seen footage of Kamilo Point, the Big Island’s infamous “plastic beach.” where tons of marine debris had accumulated near the southern end of the island.
“They figured if they could clean up Kamilo, they could clean any beach,” said Megan Lamson, president of the Hawaii Wildlife Fund.
The organization mounted a crowd-funding project to bring the prototype here and modify its trailer for off-roading so it could make it to Kamilo. Vanderzyl joined the project to measure the results.
With some tweaks, they got the prototype to work, though it had limitations. For one, it could accidentally sweep up beach residents such as small crabs, so it can only be used on beaches already so badly trashed that, as Lamson said, it can “do more good than harm.”
The prototype was left on the island when the study was over, and will be used in future beach cleanups.
The internet is already rife with photos of dead whales and seabirds with pieces of plastic spilling from their guts. But since plastics don’t biodegrade, only break into smaller and smaller pieces, there are going to be more and more microplastics and even smaller nanoplastics as time goes on. And the smaller they get, the bigger the problem, said Lamson.
“The microplastics and nanoplastics are ecologically the most toxic,” she said, “because they’re so small, and some of them are so small that they could potentially go through the cell membrane.”
“It’s like a synthetic bacteria,” said Vanderzyl. “It’s spreading everywhere like a plague, and after a while you just can’t see it.
“It’s really nerve-wracking, being the generation that was handed this.”
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