Finding microplastics in Delaware waters is not just a one-state issue

Delaware Department of Natural Resourses researcher Kari A. st. Laurent, Ph.D. taking samples of sand from Kitts Hummock Beach looking for plastic fibers. GARY EMEIGH/Special To The News Journal

[This article was originally published by The Delaware News Journal.]

For those who don’t revel in the Delmarva tradition of picking steamed blue crabs, the presence of tiny, microscopic plastics on coastal beaches and waterways may seem like a small problem.

But what if it wasn’t just sand stuck between your toes after a relaxing day at the beach? What if little pieces of plastic joined those sand granules as they swirled down the shower drain?

For Milton resident and nature lover Joanne Hampton Taylor, the idea of tiny pieces of plastic being an unseen part of the pollution found on Delaware’s beaches isn’t so surprising. She takes walks along local bay beaches searching for treasures like sea glass and Cape May diamonds about five times a week.

“There’s so much trash,” she said, noting that it appears to get worse during her winter walks. “I can’t even imagine what’s under the ocean in that area… I’ve seen little pieces of blue plastic and pink plastic and yellow plastic with little jagged edges. That’s not natural.”

When Taylor first started her trips to Delaware Bay beaches like Woodland, Slaughter, Broadkill and Fowler about five years ago, one of the first things she’d do was kick off her shoes and feel the sand on her feet as she explored the shoreline.

In recent years, though, the proliferation of trash she has seen on the beach, like condoms and needles, as well as larger rocks along some bay beaches, has made her decide to keep her sneakers on.

“We’re just trashing the ocean,” she said.

When Taylor first started these trips, she was also scared of the horseshoe crabs that would emerge along the bay shore every spring and summer. After learning that their pointy tails are for turning over, not for stinging, she joined the unofficial club of locals who flip over mating horseshoe crabs that have become stuck on their backs.

The idea that their coastal habitat now likely includes a man-made element of unseen microplastics, which might end up in the mouths of thousands of shorebirds feasting on their eggs, raises a lot of questions.

“Are they a problem? They’re an invisible problem that eventually is going to become visible,” Taylor said. “How? I don’t know if it’ll affect the water, the fish, the birds. I don’t know if it’ll affect us.”

Marine scientists are wondering the same thing.

In addition to looking for microplastics in the water, researchers throughout the Delaware River Basin also are taking a closer look for microplastics in the sand, sediments and organisms found in the Delaware River and Bay, as well as its tributaries.

“We’ve tested surface waters, beach sands and also looked at sediment and, of course, found microplastics in all of them,” said Kari St.Laurent, scientist and research coordinator at the Delaware National Estuarine Research Reserve. “We’re just scratching the surface.”

Delaware Department of Natural Resoourses researcher Kari A. st. Laurent, Ph.D. taking samples of sand from Kitts Hummock Beach looking for plastic fibers. GARY EMEIGH/Special To The News Journal

In the sand samples, she and other researchers found more microfibers and microbeads than fragments. She said they focused on beach areas where thousands of horseshoe crabs spawn and shorebirds feast on their eggs every spring.

“It was sad to see that there really was a microplastic legacy in just about everything we saw,” St.Laurent said. “It’s definitely, I think, a problem that most likely won’t go away.”

St.Laurent said a lot more work – and a lot more samples taken at different times and in different weather conditions – still needs to be done. They collected sand samples at North Bowers Beach, Kitts Hummock and at the Ted Harvey Conservation Area just to the south, all Delaware Bay beaches that are well-used horseshoe crab spawning sites.

A baseline for microplastics in the Delaware Bay has been set by a team of researchers from the University of Delaware who found microplastics in their samples at multiple sites from waters near Wilmington to the mouth of the bay, where it meets the Atlantic Ocean.

Collecting instances of these tiny microplastics from water, sand, sediment and sea life will help scientists figure out whether they pose a risk to valuable marine nursing grounds like the Delaware Bay, and ultimately whether those impacts trickle down to humans.

At the same time, University of Delaware researchers Jonathan Cohen and St.Laurent said they also hope their research will pave the way to data-driven decisions on how to curb the pollution in the first place.

“Until we understand what’s there and if it’s a problem, we can’t really formulate that plan to educate people to reduce microplastics,” St.Laurent said.

Searching for microplastics upriver

Other teams of researchers also are sampling some urban and rural areas in the 13,539-square-mile Delaware River Basin that stretches from headwaters in the Catskill Mountains all the way down to the southern reaches of Cohen’s work, where the bay meets the Atlantic Ocean.

Studies farther north are mainly waiting on collected samples to be processed and analyzed in a laboratory, so the extent, concentration and sources of microplastics pollution remain unknown.

“There’s still a lot of questions out there about if they are being ingested, what does that mean,” said Austin Baldwin, a hydrologist with the U.S. Geological Survey.

USGS and the National Parks Service collected water samples in a northern stretch of the Delaware River from Callicoon, New York, south to Burlington, New Jersey, last summer. They also collected some fish tissue and mussel samples from some of those sites, to see if microplastics are ending up in those marine animals, too. 

Delaware River Basin Commission Senior Environmental Toxicologist Dr. Ron MacGillivray preps to collect a sample from Pennsylvania’s Neshaminy Creek to analyze for microplastics.
Image courtesy of the Delaware River Basin Commission

Baldwin said the samples have been processed, but are now need to be analyzed and summarized.

Studies in other places have suggested that already existing toxins like PBTs may glob on to the plastics, adding to the potential biohazards if animals consume them.

Other studies have found that nanoplastics – the teeniest tiniest of all microplastics – may also be able to migrate through the stomach lining of an animal like a fish, rather than remaining just in the digestive tract that doesn’t end up in the fryer.

“In past studies, we’ve seen that fish and mussels and other types of aquatic organisms do ingest plastics,” Baldwin said. “So I think there’s potential there for concerns about the health of the fish, and when it comes to shellfish or mussels and bivalves and oysters and things, humans eat the whole thing.”

Meanwhile, the Delaware River Basin Commission also is awaiting analysis on its sampling, taken from more than a dozens sampling sites along the Delaware River and its tributaries, from Trenton, New Jersey, south to the Christina River in Wilmington.

DRBC aquatic biologist Jake Bransky said that as he was collecting samples alongside a boat or bridge, he was thrilled to see bald eagles and ospreys returning to even more urban areas along the river. But he also spotted large plastic pollution along the banks that could someday become future microplastics pollution.

“Just because microbeads were banned, that doesn’t mean we can close the book on microplastics,” Baldwin said. “We’re just asking the question of, ‘is it there and at what concentrations?'”

“Then we can ask the more complicated questions: Is this something we need to worry about? Is it an aquatic health issue? A human health issue? What are we dealing with?”

What are microplastics?

Microplastics are tiny pieces of plastic, smaller than 5 millimeters, which is about the size of a pencil eraser. There are three main categories of microplastics: fragments, fibers or filaments, and beads.

Fragments are pieces of plastic that started out as something larger, like a plastic bottle, bag, toy or container. Imagine crunching up a potato chip. If that chip were made of plastic, the crumbs in your hand would be microplastics.

Fibers or filaments are like tiny threads that come from clothing, rope or fishing line. Imagine a well-used microfiber fleece sweater. The little hairs that stick out of it, if they were removed one by one, would be microplastic fibers.

Beads are small, spherical plastics designed at that size, to be used in products like exfoliating face washes and toothpastes.

Microplastics can get into the environment as larger plastic litter breaks down and from wastewater treatment plants that discharge into bodies of water. They can be found in the water, sand and sediment and in marine animals’ digestive systems in aquatic environments. Microplastics have also been detected in the air we breathe, the food we eat and even the pristine snow of the Arctic.

This story has been produced as part of “From the Source: Stories of the Delaware River,” a year-long collaborative reporting project produced with support from the National Geographic Society, the Lenfest Institute for Journalism, and the William Penn Foundation. Editorial content is created independently of the project’s donors.

Do you have an environmental story tip? Contact reporter Maddy Lauria at (302) 345-0608, or on Twitter @MaddyinMilford.

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