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Plastic bags, films, polystyrene, nurdles, microbeads, and microfibers have one thing in common: they do not belong in Casco Bay. Plastics may go into the ocean, but they do not go away. According to the United Nations Clean Seas Campaign, up to 80 per cent of all litter in the oceans is made of plastic.1

Waves and sunlight can break plastics into minute particles, but no one knows how long it would take for plastic to break down completely in the marine environment. Estimates range from 50 to 500 years, although National Geographic Magazine (May 2018) stated that, “Estimates range from 450 years to never.”

Microplastics are of particular concern because they are nearly invisible to the naked eye. Microplastics are defined as pieces of plastic, primarily in the form of fragments, films, fibers, or microbeads, which are 5 millimeters (mm) or smaller; that is less than a quarter of an inch long.

No matter what the size, plastic pollution in the ocean is a huge problem. The ocean is downstream from everything. According to the United Nations (UN), more than 800 tons of plastics end up in our oceans each year. UN scientists estimate that as much as 51 trillion microplastic particles—500 times more than the stars in our galaxy—litter the seas.1

A 2016 report predicts that by 2025, the ocean may contain one ton of plastic for every three tons of fish! By 2050, unless things change, estimates are that there will be more plastic than fish in our oceans (by weight). 2

Microplastics can displace plankton as food. Because they cannot be digested, microplastics may become concentrated in the flesh of mussels and oysters. It has been calculated that Europeans who eat these shellfish consume about 11,000 microplastics per year.3

Persistent organic pollutants, such as DDT and PCBs, can adhere to microplastics4, making ingestion by marine life, and indeed, human beings, even more toxic.

Are there microplastics in Casco Bay?

Yes, we found microplastics in Casco Bay.

Maine researcher Abby Barrows has been testing water samples from the world’s oceans, collected by members of Adventure Scientists. Nearly every sample contained plastics.

As the group that protects the health of our coastal waters, and with plastics being a worldwide problem, Friends of Casco Bay felt it was our duty to see if microplastics were present in the Bay.

Over the course of two days in June 2017, we collected jars of seawater at 16 sites in four regions of the Bay, to determine if microplastics were present. We collected four two-liter samples in four different regions of Casco Bay: in Portland Harbor, between Chebeague Island and Cousins Island, in Merepoint Bay, and offshore near Halfway Rock.

We used a protocol provided by Abby Barrows, formerly with the Marine Environmental Research Institute (MERI) and now with Adventure Scientists. Abby analyzed our samples.

The simple goal of our study was simply to see if we would find microplastics in Casco Bay. We did.

What did we find?

We found 20 microplastic pieces in total; half of the pieces were from Portland Harbor. Of the 20 pieces of microplastics, 19 were less than 1.5 mm (smaller than 1/16 of an inch). 14 of 20 pieces were microfibers. Microplastic films and fragments were present as well. No microbeads and no nurdles were found.

Some microplastics may be derived from shredded or degraded plastics, such as plastic bags, packaging materials, and clothing made from synthetic materials.

We found the highest number of microplastics in the samples taken closest to shore (10) in Portland Harbor, where sewer outfalls, sewer overflows, and stormwater wash debris into the Bay. We found fewer microplastics around Cousins Island (4), Merepoint Bay (3), and Halfway Rock (3).

As Friends of Casco Bay Research Associate Mike Doan observes, “I think the important message is that we found microplastics in every region of the Bay, just by grabbing a sample of water.” The fact that we found them at every place we sampled, even ten miles from land, is cause for concern.

We will continue to follow ongoing research and consult with other scientists who are studying microplastics in Maine, including Abby Barrows and Madelyn Woods of MERI, who is studying microplastics in mussels and oysters. We also want to compare our results with what is being documented in other water bodies.

Microplastics—in many forms

Microplastics come from a variety of sources, including from larger plastic debris fragmenting into ever smaller pieces. Sunlight and wave action break apart plastic litter, making transport in water easy and clean up difficult. Some microplastics are manufactured as tiny, round beads to be used in facial scrubs, body washes, and toothpaste; others, called nurdles, are pea-sized plastics that can be melted and molded into every imaginable form of plastic we might use. Microplastic fibers are shed from fleece and other synthetic textiles as they tumble and spin in washing machines. These fibers are carried away in the rinse water to sewage treatment facilities, septic systems, or waterways that may link to the ocean.

While some microplastics may get trapped in sewage sludge, unknown quantities of these tiny particles pass through the filtration systems of wastewater treatment plants and are discharged into our waterways.


How would we get through a Downeast winter (or any season in Maine, for that matter) without a stockpile of warm fleece jackets? Who knew that these are a major source of microplastic fibers in our waters? Microfibers are micron-scale synthetic fibers, mostly polyester and acrylic. The majority of microplastics we found in Casco Bay were microfibers.

study published in 2011 cited experiments sampling wastewater from household washing machines, which found that a single garment can produce over 1,900 fibers per wash. The same study found microplastic contaminants on 18 beaches on six continents, from the equator to the poles. 5

Recent research suggests that microfibers are more abundant in our lakes and rivers than microbeads. In 2014, Sherri “Sam” Mason, a chemist at the State University of New York at Fredonia, assigned two students to study the guts of fishes caught by sports fishermen in Lake Erie. They found plastic in most of the fishes they examined. The majority of plastics they identified were microfibers. When she viewed the samples under a microscope, Professor Mason found, “Rather than passing through the fishes’ guts, the fibers seemed to be woven into them.”6 That should be concerning for all who eat fish.

Plastic bags

Plastic bags can become marine hazards in a number of ways. Littered and blown across the landscape, they can clog storm drains. This can result in flooding and overflows of sewage mixed with stormwater, a toxic mix with an expensive fix for public works departments.

Plastic bags that end up in the ocean may be mistaken for jellyfish and other translucent creatures, becoming “food” for sea turtles, seabirds, marine mammals, and some fish. There are a number of documented scientific studies—and horrific photographs—of marine animals that died, often from starvation, by ingesting plastics.


Plastic films may be disintegrated garbage bags, bubble wrap, shrink wrap, stretch wrap, envelope liners, I.V. bags, garment bags, and thousands of other products. We are probably most accustomed to seeing plastic films in supermarkets, protecting meats, seafood, and vegetables. Plastic films are used in many other industries, including building construction, landscaping, electrical fabrication, movie making, and photography.

The trait that all plastic films have in common is that the final product is flexible, as opposed to rigid like soft drink bottles or butter tubs. One of our Casco Bay microplastics samples contained a film. Once in the marine environment, these fragile-looking materials persist, even as they fragment into microscopic-sized pieces.7


Polystyrene is found in cups, plates, take-out food containers, and packing materials. Polystyrene can be formed into hard plastics, such as eating utensils and CD and DVD cases. One form commonly known as Styrofoam is lightweight and can float at the surface where many marine animals feed.

Sea creatures may mistake polystyrene for food, and they cannot digest it. As with other plastics, a wide variety of toxic chemicals can adhere to polystyrene, making ingestion an even riskier proposition.

Studies have found styrene residues in 100% of all samples of human fat tissue, leached from food and beverage containers. Exposure to these toxins increases the risks of leukemia and lymphoma.8


Microbeads are tiny, synthetic plastic granules used as abrasives and cleansers in many personal-care and beauty products, such as cosmetics, facial scrubs, shaving creams, fluoride and whitening toothpastes, moisturizing cleansers, and wrinkle creams. These tiny plastic particles are designed to be washed away, but they don’t go “away.”

Ten to 100 times smaller than a grain of sand, microbeads can pass through wastewater treatment plants into streams and rivers and ultimately into our coastal waters.


Nurdles are pea-sized pellets of plastic, formed into a variety of shapes and colors. They are the building block of all other plastics. Nurdles are melted down and made into anything and everything composed of plastic. According to Charles Moore, the sailor/scientist who discovered the North Pacific Garbage Patch in 1997, these resin pellets are the raw material for the 260 million tons of plastic used worldwide each year.9

When these plastic particles end up in the ocean, Surfers Against Sewage and other ocean advocates refer to nurdles as “mermaids’ tears.”

Small and lightweight, nurdles can find their way into the marine environment if they are spilled during shipping or handling. Not surprisingly, they are ubiquitous in the ocean and along our coastlines. In the United Kingdom, nurdles are the second most common plastic litter found on beaches, according to the Marine Conservation Society’s 2007 data and a Surfers Against Sewage report.10

Like other forms of plastic, nurdles can be a threat to the health of the ocean ecosystem. These pollution sponges readily absorb and concentrate harmful pollutants from seawater.

Because of their size, shape, and color, they are often mistaken for food by seabirds and marine life. Plankton eaters seem to prefer tan nurdles, which mimic the color of plankton. Seabirds often favor oval-shaped nurdles, which apparently look like fish eggs. Nurdles were found to have been consumed by more than 70 different species of seabirds. Once inside the ocean food web, contaminated nurdles can expose marine creatures to toxic levels of pollutants such as DDE (a derivative of DDT) and PCBs.11

What is Friends of Casco Bay doing about plastic pollution in the ocean?

We are using science, advocacy, and community engagement to try to reduce plastics pollution. We plan to repeat our sampling project in 2019 and compare with our 2017 findings and those of other researchers from other regions.

Our Executive Director Cathy Ramsdell served for two years on Portland’s Green Packaging Task Force, which crafted two ordinances that became models for many other communities: a ban on polystyrene and a fee on single-use shopping bags. As of 2017, restrictions on single-use plastic bags have been implemented in Portland, South Portland, Brunswick, Topsham, Windham, Saco, Falmouth, York, Kennebunk, Freeport, and Belfast, Maine.

In 2015, Friends of Casco Bay urged our members to lobby their legislators to pass a state law to ban products containing microbeads. The Maine Legislature passed a law to phase out the manufacture and sale of microbeads. Soon after, following the lead of Maine and other states, the federal government took similar action, requiring that companies phase out the production of plastic microbeads by the end of 2019.

Casco Baykeeper Ivy Frignoca is working at the state level, supporting a bill to create the Maine Marine Debris Study Commission to examine policies, partnerships, and research priorities to help address the issue.

In presentations at community events, such as Fisherman’s Forum and eco-fairs to local organizations and clubs, we describe the impacts of plastics in the ocean and suggest ways to limit their use.

What can you do about plastics pollution?

Take action!

  • Support legislation to establish a state Marine Debris Study Commission
  • Support local ordinances in your town to reduce plastic waste, including local bans on the use of polystyrene food containers. Where bans are in place, retailers use compostable or recyclable containers.
  • Volunteer for shoreline cleanups. Of the top ten items picked up at international beach cleanups, all but two (cigarette butts and glass bottles) were plastic items: bottles, caps, grocery and other plastic bags, lids, straws, foam carryout containers, and food wrappers.12
  • Help us tackle the biggest threats to the Bay by supporting our work with a donation.
  • Sign up for our emails so you can stay informed about this issue.

Wash with care

  • Before you buy, make sure that personal grooming products don’t contain microbeads. Check the label for Polyethylene (PE), or Polypropylene (PP). Either indicates microbeads in the product.
  • Wear clothing and use bedding made of natural fibers such as cotton, linen, and wool instead of synthetic materials, such as polyester and fleece.
  • If you already own these synthetics, wash less frequently and for a shorter time.
  • Switch to liquid laundry soap. Laundry powder “scrubs” and loosens more microfibers
  • Use a colder wash setting. High temperature can damage clothes and release more fibers.
  • Be on the lookout for new washing machine products coming onto the market that are designed to capture microfibers. A laundry ball called the “Cora Ball” acts like a hairbrush. A “Guppyfriend Wash Bag” traps fibers that then can be removed by hand.
  • Deposit washing machine and dryer debris in the trash, not down the drain or the toilet.

Pick your packaging wisely

  • Use reusable water bottles and cups
  • Use reusable shopping bags
  • Buy in bulk
  • Say no to straws
  • Choose glass over plastic; use metal instead of plastic cutlery
  • Avoid travel-size wash products
  • Bring lunch from home so you aren’t tempted to buy take-out food in Styrofoam containers

1 “‘Turn the Tide on Plastic’ urges UN, as microplastics now outnumber stars in our galaxy,” United Nations Clean Seas Campaign, UN News, February 23, 2017

2 “The New Plastics Economy — Rethinking the future of plastics,” World Economic Forum, Ellen MacArthur Foundation and McKinsey & Company, 2016

 3 Lisbeth Van Cauwenberghe with Colin R. Janssen, “Microplastics in bivalves cultured for human consumption,” Environmental Pollution, October 2014, Vol. 193, October 2014, pp. 65-70

4 Yukie Mato et al., “Plastic resin pellets as a transport medium for toxic chemicals in the marine environment,” Environ. Sci. Technol., 2001, Vol. 35, No. 2, pp. 318–324

5 Mark Anthony Browne et al., “Accumulation of Microplastic on Shorelines Worldwide: Sources and Sinks,” Environ. Sci. Technol., 2011, Vol. 45, No. 21, pp. 9175–9179

6 “Freshwater’s Macro Microplastic Problem,” Nova Next, May 11, 2017

7 Understanding Plastic Film: Its Uses, Benefits and Waste Management Options, American Plastics Council, December 1996 

8 “Toxnet Hazardous Substances Data Bank, Styrene, CASRN: 100-42-5 (Human Health Effects)” National Library of Medicine, revised November 1, 1994 

9 Claire LeGuern, “When the Mermaids Cry: The Great Plastic Tide,” Coastal Care, coastalcare.org, updated March 2018  

10 Julie-Beth McCarthy, “Plastic Pollution: Nurdles,”  www.savetheblue.com podcast, July 27, 2011

11 Ibid.

12 Together for Our Ocean: International Coastal Cleanup 2017 Report, Ocean Conservancy, Washington, DC, 2017