Taking a closer look at microplastics on N.H. beaches

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Despite efforts to keep N.H.'s beaches free of litter, a closer look reveals tiny bits of plastic embedded in the sand. Plastic pieces less than 5 mm — about the size of a small button — are called microplastics. With funding provided by a N.H. Sea Grant (NHSG) development grant, Gabriela Bradt, commercial fisheries specialist for NHSG/UNH Cooperative Extension, will examine the prevalence of microplastic debris on beaches in the Granite State for the next year.

Based on data collected during beach clean-ups with the Blue Ocean Society, Bradt said that approximately 82% of the litter found on N.H. beaches is some form of plastic. Soda bottles or buckets are the easiest targets for volunteers to pick up and dispose, but the microplastics are often overlooked because of their size.

"The longer the plastic stays out in the ocean and on our beaches, the more brittle it becomes," said Bradt. "It then breaks down into smaller pieces, becoming more difficult to find and pick up while potentially leaching chemicals into the environment."

Marine mammals, sea birds and other wildlife could ingest the microplastics unknowingly, and that may cause them additional harm either from the plastic itself or from chemicals leaching out of the plastic, she said. Microplastics have the potential to become a human health hazard if found in large enough amounts.

Bradt recently trained citizen scientists from NHSG's Coastal Research Volunteer (CRV) Program and a few of the UNH Marine Docents to help with the microplastics data collection. Before searching the sand for tiny pieces, they first had to find the exact sampling location to maintain consistency in the data. Using an app called Survey GPS on their smartphone or iPad, these citizen scientists searched for their designated spot in the sand in the highest wrack line — the spot on the beach farthest from the ocean where a high tide deposited seaweed and other debris. After setting up a one-meter-square quadrat around that point, the volunteers removed any dried seaweed or large pieces of debris to clear the sand surface. Using a trowel, they skimmed the top of the quadrat evenly and filled a two-gallon bucket. This sand was sifted through two different sized sieves — 5 mm and 1 mm. Any pieces caught in the sieve were placed in a sample bag and labeled for sorting back in the lab at a later time.

The volunteers will repeat these sampling procedures in two other locations 30' on either side of the first site. Sampling took place at 12 of the 16 assigned N.H. beaches in October 2013 and is also scheduled for mid-March to mid-April, and August 2014. Sorting the microplastics will take place during the months between beach sampling, which will help determine the amount and types of plastics most prevalent on the beaches.

Bradt hopes the data will reveal trends including which beaches have a higher prevalence of microplastics and if the season influences their abundance or location. Depending on the availability of funding, future research efforts might include a chemical analysis of the microplastics to determine what, if anything, could leach out of the plastics, she said. But what Bradt really hopes for is a change in behavior of the people who litter — if people can be taught that plastic doesn't ever really "go away," then perhaps they will think twice before littering and instead pick up any debris they see and dispose of it properly, she said.

To find out more information about the project or to volunteer, please contact Gabby Bradt at 603.862.2033 or gabriela.bradt@unh.edu

Check out this research in action in our video: 


Rebecca Zeiber, N.H. Sea Grant Science Writer