Just a year ago, lava flows from the Kilauea volcano, a burle, blocked roads and flowed through the fields of Hawaii. They eventually reached the ocean, where hot lava met cold sea water and shattered into tiny shards of glass and rubble, forming sand.
This is how new beaches appeared, such as Pohoiki, a black sand beach that stretches for 1000 feet on the Big Island of Hawaii. Scientists investigating the area are unsure if the beach formed immediately after the May 2018 volcanic eruption or if it formed slowly as the lava began to cool in August, but what they know for sure after examining samples taken from the newborn beach is that that it’s already contaminated with hundreds of tiny pieces of plastic.
Pohoiki Beach is further proof that plastic is ubiquitous these days, even on beaches that look clean and pristine.
Microplastic particles are usually less than five millimeters in size and no larger than a grain of sand. To the naked eye, Pohoiki beach looks untouched.
“It’s incredible,” says Nick Vanderzeel, a student at the University of Hawaii at Hilo who discovered the plastic on the beach.
Vanderzeal saw this beach as an opportunity to study new deposits that may not have been affected by human influence. He collected 12 samples from different points on the beach. Using a solution of zinc chloride, which is denser than plastic and less dense than sand, he was able to separate the particles—the plastic floated to the top while the sand sank.
It was found that, on average, for every 50 grams of sand, there are 21 pieces of plastic. Most of these plastic particles are microfibres, fine hairs that are released from commonly used synthetic fabrics such as polyester or nylon, Vanderzeel says. They enter the oceans through sewage washed out of washing machines, or separated from the clothes of people swimming in the sea.
Researcher Stephen Colbert, a marine ecologist and Vanderzeal’s academic mentor, says the plastic is likely washed away by the waves and left on the beaches, mixing with fine grains of sand. Compared to samples taken from two other neighboring beaches that were not formed by volcanoes, Pohoiki Beach currently has about 2 times less plastic.
Vanderzeel and Colbert plan to constantly monitor the situation at Pohoyki Beach to see if the amount of plastic on it is increasing or staying the same.
“I wish we hadn’t found this plastic,” Colbert says of the microplastics in Vanderzeal’s samples, “but we weren’t surprised by this finding.”
“There is such a romantic idea about a remote tropical beach, clean and untouched,” Colbert says. “A beach like this doesn’t exist anymore.”
Plastics, including microplastics, are making their way to the shores of some of the most remote beaches in the world that no human has ever set foot on.
Scientists often compare the current state of the ocean to plastic soup. Microplastics are so ubiquitous that they are already raining down from the sky in remote mountainous regions and ending up in our table salt.
It is still unclear how this excess of plastic will further affect marine ecosystems, but scientists suspect it could have dangerous consequences for wildlife and human health. More than once, large marine mammals such as whales have washed ashore with piles of plastic in their entrails. Recently, scientists have discovered that fish swallow microplastic particles in the first days of life.
Unlike larger plastic items such as bags and straws that could be picked up and thrown in the trash, microplastics are both plentiful and invisible to the naked eye. One recent study found that millions of pieces of plastic remain on beaches even after cleaning.
Conservation groups like the Hawaiian Wildlife Foundation have teamed up with universities to develop beach cleaners that essentially act like a vacuum, sucking up sand and separating microplastics. But the weight and cost of such machines, and the harm they cause to microscopic life on beaches, means they can only be used to clean up the most polluted beaches.
Although Pohoiki is already filled with plastic, it still has a long way to go before it can compete with places like the famous “trash beach” in Hawaii.
Vanderzeel expects to return to Pokhoiki next year to see if the beach will change and what kind of changes it will be, but Colbert says his early research already shows that beach pollution is now happening instantly.