Microplastics and Plankton

by Ivy Munnerlyn, NEC Coastal Programs Coordinator

If you’ve been reading EcoNews for a while, you’ve probably heard of microplastics. These tiny, ubiquitous plastic pieces are a major headache for folks who care about the health of our oceans and waterways. They seem to be everywhere, from the deepest undersea trenches to the glacial ice of the North Pole. Microplastics come in many forms and can affect life in the ocean at every level of the food chain, from the tiniest plankton to bigger fish and marine mammals. 

There are four main types of microplastics: fragments, nurdles, microbeads, and microfibers. Microplastic fragments are probably the ones you’re most familiar with — these are the tiny pieces that break off from larger items, like a plastic bottle cap. The second category is a little more obscure; nurdles are small plastic beads that manufacturers produce and sell to other companies to melt down into the items we buy at the store (think of them as the “raw material” that makes your toothbrush). These microplastics can be released into the ocean when a shipping container on a cargo ship goes overboard. 

Microplastic poses a growing concern in oceans and other aquatic habitat. (Image by 5Gyres, courtesy of Oregon State University)

The third type of microplastics is one you might be familiar with — microbeads. These are tiny plastic balls that get incorporated into our personal care products as exfoliants. You can avoid these microplastics by checking for “Polypropylene” and “Polyethylene” on the ingredients list when buying toothpaste and face wash. The fourth category of microplastics is the one we’ll be focusing on today: microfibers. When we wash clothes made of synthetic fibers, thousands of tiny plastic threads are swept into the waste water stream, eventually flushing out into the ocean. Acrylic fabrics are the most notorious, releasing over 700,000 fibers on their first wash. Subsequent washes release less fibers, but that’s still a lot! It’s no wonder microfibers are one of the biggest contributors to microplastic pollution. But what does washing your new Patagonia fleece have to do with the marine food chain?

To answer that question, we have to start with the organisms at the very bottom of the food chain: plankton. Plankton is the general term for the billions of microscopic creatures that live in our oceans and waterways. The word plankton comes from the Greek for “tiny drifter,” and that’s precisely what they are. Plankton are too small to chart their own path through the tides — they simply drift along, hoping to run into some food along their journey. Zooplankton — which can look like miniature shrimp, electric razors, or hairy worms — are happy to gobble up anything smaller than they are. Often, this includes microfibers and other microplastics. 

Amphipod Diporeia. Actual size 7.8 mm. Microphotograph taken by M. Quigley April 2000.

According to a 2019 paper by Vivian S. Lin, zooplankton that consume plastics suffer decreased appetite and reproductive success. Not only that, but the microplastics can travel up the food chain to the bigger creatures that eat zooplankton — like fish and shellfish. Microplastics have been found in samples from seafood markets, so they affect us too!

You might be wondering, what can I do about the issue of microplastic pollution? It’s one of those frustrating problems that could be more efficiently solved if companies simply made a few changes to their products. But there are several ways we can reduce the amount of microfibers going down the drain, and they’re all pretty easy! First, we can choose to buy clothes made of natural fibers like cotton, hemp, wool, and silk. There’s no danger in washing these items, but they can be a little pricey — and if you’re like me, you probably own several fleece jackets that you’d be sad to part with. The next best option is to simply wash your synthetic fiber clothes less often. A spot clean here and there and a few hours hanging outside can go a long way for freshening up clothes in between washes. A third option is to invest in one of several products that help trap microfibers before they leave your washing machine. The Guppyfriend Wash Bag, Cora Ball, and Lint LUV-R all filter out some of the fibers that would normally end up in the ocean. And if you want to help reduce other forms of microplastic litter, there’s always a good old fashioned beach cleanup! If you’re interested in getting started as a cleanup volunteer, check out our Trash Trackers program on our website. No experience required — just a passion for keeping our streets and beaches plastic-free. 

When you pick up a plastic water bottle off the beach, you’re preventing that bottle from floating out to sea and becoming food for plankton as it breaks down. Microplastics can seem like an issue too big to tackle — but rest assured, there are plenty of ways to help!

Want to learn more? Check out these YouTube videos: