UH Hilo senior Nicolas Vanderzyl, majoring in marine science, is collecting and analyzing data about the effectiveness of a new machine designed to remove microplastics from the sediments of beach sand. The research is being conducted at Kamilo Point on Hawai‘i Island.
By Leah Sherwood.
A machine built to filter microplastics from the sand on one of Hawai‘i’s dirtiest beaches has been delivered to the island of Hawai‘i, kicking off a collaboration among the University of Hawai‘i at Hilo, the Hawai‘i Wildlife Fund (HWF), and engineering students from the Université de Sherbrooke in Québec, Canada.
The machine, named Ho‘ola One (“bring life back to the sands” in Hawaiian), is designed to filter out microplastics (small plastic fragments less than five millimeters long) while allowing natural sand and rocks to pass through.
“I think these really small pieces of plastic that have accumulated on our beaches are a problem for the environment,” says Steven Colbert, an associate professor of marine science at UH Hilo. “Removing those from the sediments is definitely an important part of the process of returning these coastal habitats back to a more pristine state.”
Nicolas Vanderzyl, a UH Hilo senior in the marine science department who Colbert is mentoring, is working with the Hawai‘i Wildlife Fund to measure how effective Ho‘ola One is at removing the microplastics from sediments at Kamilo Point, Hawai‘i Island, by comparing the sediments before and after the filtering. In a previous research project, Vanderzyl measured the microplastic accumulation patterns on three beaches on the island of Hawai‘i—Hilo Bay, Hapuna, and Pohoiki, the newly formed beach created by the 2018 Kīlauea eruption. To Vanderzyl’s surprise, he found that the data from his samples revealed no significant difference in the amount of microplastics among the three beaches.
Plastic pollution has become a major environmental threat in the world’s oceans and on its beaches. The island of Hawai‘i’s Kamilo Point, which is known for its accumulation of garbage and marine debris from the Great Pacific Garbage Patch, is sometimes referred to as “junk beach,” a reference to the thousands of pieces of plastic that wash up on its shores. The Hawai‘i Wildlife Fund has removed more than 268 tons of marine debris from this part of the island since 2003, the majority of it plastic.
Removing plastic from the beach is important not just aesthetically but also because it protects Hawai‘i ’s wildlife, from birds who ingest the microplastics (which resemble fish eggs) to sea turtles who become trapped in discarded fishing nets.
Ho‘ola One was designed and built by a team of 12 engineering students at the Université de Sherbrooke in Québec. “It’s basically a big vacuum cleaner that someone operates,” explains Alexandre Savard, who leads the team of students. “We vacuum everything into an empty reservoir, and once the reservoir is full, a six-inch valve opens and drops everything down into a decanter, which is full of seawater. It has big heavy jets to mix everything and then big manifolds to stop the turbulence. After decantation the plastic floats on the top while the sand and rocks sink to the bottom. The plastic is filtered from the water with stainless steel filters and the sand and rocks are returned straight to the beach.”
Once Savard and his team had a viable prototype of the machine in Québec, they contacted HWF to ask if they could test the machine at Kamilo Point.
“They had a two-year project and had heard about Kamilo Point, and wanted to do something about plastic pollution and microplastics,” says Megan Lamson, marine scientist and president of Hawai‘i Wildlife Fund. “It’s a huge issue and nobody has found a successful way to clean up the debris. We’ve tried everything from sifting trays to flotation, and we really hope this works, because it’s going to be a lot more efficient.”
Lamson, an alumna of UH Hilo’s graduate program in tropical conservation biology and environmental science, notes Vanderzyl’s evaluation of the effectiveness of Ho‘ola One is being supported by Hawai‘i Wildlife Fund, which has a long history of collaboration with UH Hilo. “HWF is a volunteer-powered organization, and we are reliant on strong community and agency partnerships to pursue our mission through research, education, and conservation projects,” says Lamson. “Over the years, we have supported numerous UH Hilo graduate and undergraduate students working on studies related to both plastic pollution and sea turtles.”
Lamson notes that collaborative plastic marine debris research between HWF and UH Hilo over the past 15 years includes studies on sources and sinks, accumulation rates, ingestion evidence, beach structure and composition, policy endeavors, data collection, and removal efforts. She and the HWF monitor and record the types of plastic marine debris found in the environment in order to support legislative action, to extrapolate trends in the debris accumulation data, and in some cases to track the plastic pollution back its the source.
The study of marine debris
Assoc. Prof. Colbert, a coastal hydrologist and Vanderzyl’s mentor, supports the Ho‘ola One initiative. Colbert has researched and published on microplastics in sediments and teaches a class on plastic marine debris at UH Hilo. He has brought his students to Kamilo Point to see the plastic accumulation for themselves.
“Our beaches are an important sink of marine debris,” Colbert adds. “We have estimates of how much plastic is coming into the ocean and how much is floating in the ocean and they don’t match up. We don’t know where the plastic is going. Is it sinking onto the sea floor? Accumulating on our beaches? Is it being eaten by birds or carried onto land? How is it accumulating and where is it accumulating? It’s not well documented.”
Colbert stresses that ultimately the problem of plastic pollution needs to be addressed at the source. “We need to support legislation that helps to reduce the amount of plastic that we use, and vote for people who are going to support that kind of legislation,” he says. “Furthermore, most of the mass of marine debris that washes up at Kamilo is fishing nets, so we really need regulations that prevent their improper disposal. In the big picture those are the things that are most the effective.”
About the author of this story: Leah Sherwood is a graduate student in the tropical conservation biology and environmental science program at UH Hilo. She received her bachelor of science in biology and bachelor of arts in English from Boise State University.