Plastics & Microplastics


Most of us know about the plastic gyres twice the size of Texas in the Pacific Ocean, and how plastic debris is choking marine mammals, filling the stomachs of seabirds, and suffocating coral reefs. What we may not realize, however, is what we cannot see: microplastics. Microplastics are the most abundant form of solid-waste pollution on Earth and are one of the most critical ocean pollution concerns of our time.

It is estimated that eight million metric tons of plastic now pollute the world’s oceans. Over time, most of this plastic breaks down into tiny pieces less than 5 millimeters in length, which are consumed by marine wildlife and contaminate the food we eat. These microplastics pose a serious risk to ocean and human health, from the Pacific coast to the beautiful waters of Maine.

Pioneering Microplastics Research in Maine and Beyond

The Marine & Environmental Research Institute has pioneered research on microplastic pollution, and, at present, we are the only institute with a focused microplastics research program in Maine.

In 2012, we developed an innovative method to measure microplastics in seawater which is  being shared with other research groups around the country. The following year, our monitoring team detected staggering amounts of microplastic fragments in water samples collected from Blue Hill and Penobscot Bays – on average, 17 plastic fragments in every liter of seawater. This finding took us by surprise.  

Curious about where microplastics came from, we looked at possible sources: wastewater treatment/sanitary district outfall pipes, regions of high-density lobster gear, and compared them with deep, high-water turnover control sites. 

No one expected to find that much plastic in "pristine" Maine waters, let alone amounts on par with those in heavily industrialized coastal areas.

But, most surprising: The main source of the microplastics are consumer products coming through our wastewater — abrasive microbeads in beauty products released into sinks and shower drains, and microplastics from synthetic clothing released during washing. These tiny plastic fragments are too small to be captured by existing wastewater treatment processes and wind up in the ocean. There is an urgent need for public awareness of the contribution of synthetic clothing and beauty products to plastic pollution of coastal waters.

To advance understanding of microplastic pollution in Maine, the Institute monitors input sites including stream and river mouths. The results generated from our research will fill knowledge gaps in the field. Our findings also inform legislation and public policy. Through education and media, we inspire citizen actions to help mitigate plastic and microplastic pollution.

Microplastics in Seafood

In 2014, we developed a study to measure microplastic fragments in Maine seafood. We found surprisingly large numbers of microplastic fragments in oysters and mussels. Oysters had the highest number of fragments, averaging 177 pieces per animal. Both rope-grown and wild caught mussels had similar levels. These numbers show microplastics may pose a serious health threat to the animals themselves and seafood consumers.

More than half of the plastics produced on a global level are associated with hazardous plasticizer additives and chemicals that cause endocrine disruption, reproductive effects, neurodevelopmental effects and cancer. The widespread presence of microplastics in the ocean is concerning because of their potential toxicity and because many organisms including fish and seabirds mistake them for food.

When marine animals ingest microplastics they can concentrate plasticizer chemicals like phthalates and organic pollutants (e.g., PCBs, flame- retardants, DDT) absorbed from the surrounding seawater. Although this is still new research, studies show these chemicals can cause adverse effects in animals, such as liver damage in small fish and death in lungworms.

The bottom line is, if current trends continue, our seafood may be less of a healthy food choice than we think.

The possible crippling effect of microplastic contamination on the seafood industry drives us to accelerate our research efforts. We are not only concerned for the health of our marine species, but by better understanding microplastics, we can help protect the health of seafood consumers.

From Laboratory to Legislature

Our findings of microplastics in coastal waters and seafood are already informing legislation to reduce plastics and microplastics in Maine. In 2014, we testified in support of LD 85 – An Act to Prohibit Synthetic Plastic Microbeads in Personal Care Products in Maine, which passed unanimously.

We are also providing testimony in support of upcoming bills in the Maine legislature to reduce plastic pollution: 

  • LD 427 – An Act to Address and Mitigate the Effect of Marine Debris
  • LD 325 – An Act to Strengthen Recycling of Single-use Plastic Shopping Bags
  • LD 396 – An Act to Encourage the Use of Alternatives to Single-use Plastic Disposable Bags

What You Can Do

You may be asking, “What can be done?” We must change. We must change our relationship with plastics, the convenience of plastics, our reliance on plastics in our daily lives. We need to think hard about our use of plastics and how we can reduce it by substituting safe materials. We also need and deserve protection from tougher legislation to protect human health and our environment from plastic pollution.

There are encouraging signs. In communities across the country, people are starting to take actions to ban the use of single-use plastic bags and re-use bags used in supermarkets. These and other social changes can and will make a difference.