If you’ve kept even half an eye on eco-aware headlines in the past twenty years, you’ve seen the word microplastics. What it means is simple: any piece of waste plastic less than 5mm in size, or in other words, smaller than a ladybug or a baby aspirin, is considered a microplastic. And many pieces are much smaller, extending down into plastic particulate too small to be seen with the naked eye.
Microplastics come from many sources including plastic waste being broken down by sunlight and battering, glitter and abrasives from cosmetics, or fibers from plastic-based clothing. For decades, environmental scientists have been concerned with the accumulation of microplastics in the oceans and their effects on life there.
Recently, an international research team led by Dr. Ian Kane, of the University of Manchester, did a study on pollutants on the sea floor. They discovered “hot spots” of microplastic accumulations, where currents have carried shocking amounts of the pollutants to sea floor garbage patches. In one such hot spot, evaluating a single square meter of sea floor aggregate found almost 2 million individual pieces of microplastic.
Due to the nature of deep sea currents and the things they carry, the places the currents concentrate this garbage is the same place they concentrate nutrients, making them important breeding grounds for all the varieties of filter-feeding sea life, which includes squirts, sponges, cold water corals, and the larvae of many other creatures. All of these are particularly vulnerable to pollutants, and they also form the foundation of the oceanic food chain.
Filter-feeders are eaten by fish, which are eaten by larger fish, and so on, leading to an increasing concentration of microplastics in the body of each successive predator. The researchers also pointed out that directly above their study area were major fisheries for bluefin tuna, swordfish, and grouper, all intended for human consumption with their plastic contamination intact.
Although we as individuals can do some things to control the spread of microplastics—such as avoiding “fast fashion” which is often made with plastic products—the most powerful and meaningful steps would need to cone from government, and from the waste and water treatment industries. Water treatment plants can, for example, use filtration to prevent microplastics from reaching the sea in the first place.
“These filters exist, for example, graphene filters developed at the University of Manchester and a new nanocellulose filter developed in Finland,” said Dr. Ian Kane, lead author of the study, “but it’s really at the governmental policy level that these need to be implemented.”