Behind the Catch
Ghouls, Goblins, and Garbage: Plastic Pollution in Marine Environments
This is the third blog in our series, Behind the Catch, in which we explore New England’s waters and fisheries from a scientific perspective. By examining the region’s fundamental ecology, we can better discuss and tackle marine conservation issues.
Halloween is for dressing up, carving pumpkins, and eating spooky amounts of candy. Each year, Americans buy 600 million pounds of candy for the holiday. If we pooled all our sweets together, the pile would be six times larger than the Titanic.
Unfortunately, lots of candy means lots of unrecyclable wrappers, and lots of unrecyclable wrappers contribute to the 17.6 billion pounds of plastic that enter our ocean annually. That’s the equivalent of a garbage truck dumping a full load of plastic into the ocean every minute.
Thankfully, concern about ocean plastic pollution has finally reached mainstream media. But this challenge is often impossible to see. Most recently, research has focused on one of ocean pollution’s smaller but more serious problems: microplastics.
Microplastics are defined as plastic debris less than ~5mm across. They form as sunlight, wind, and seawater weather plastic entering the oceans from coastal areas, predominately from rivers. Inevitably, plankton, bivalves, fish, birds, whales, and more mistake the debris for food, ingest it, and suffer severe consequences.
For example, microplastics can block digestive tracks and fill stomachs with undigestible material. Consequently, organisms experience a reduced appetite and malnutrition. This is a particular problem for larval fish. Because their developing stomachs are so small, a single microplastic can take up enough space to cause starvation.
Microplastics can also cause harm beyond the immediate impacts on digestion. These particles contain dangerous chemicals and provide a surface for free-floating pollutants to stick to. Once ingested, these pollutants have been shown to interfere with biological processes, such as reducing sperm production in oysters and inhibiting liver function in fish.
Even spookier are nanoplastics, which are less than 0.5mm across and may be more dangerous than microplastics. Researchers know less about nanoplastics’ effects, but it’s safe to assume they are not good. Found in cosmetics and pharmaceuticals, these microscopic plastics are especially efficient carriers of chemicals and pollutants. In particular, nanoplastics harbor endocrine disruptors, man-made molecules that interfere with reproduction in humans and animals.
While scientists are still working to understand how microplastics and nanoplastics affect populations rather than individual organisms, it is clear that these tiny particles pose big challenges for species all over the world—including humans.
A 2019 study estimated that Americans consume between 70,000-to-121,000 microplastics every year (but that number may be low since we breathe in airborne particles, too). Initial reports indicate that microplastics might have a “minimal” contribution to cell damage, lung damage, inflammation, and other issues. However, researchers have only recently begun to examine how microplastics get into our food system and affect our bodies.
While the health effects on people remain under-studied, the socioeconomic consequences are more clear. One study found that the global economic losses of plastic production, as related to marine natural capital, could conservatively equal $3,300-33,000 per ton of plastic produced annually.
Microplastics also harm humans whenever they threaten the fisheries we rely on. A major source of protein, seafood makes up 20% of all diets. If microplastics continue to affect commercial fisheries and aquaculture, billions of people could experience food insecurity.
Addressing the Problem
Plastic pollution occurs in virtually every environment on the planet. As Julian Kirby, a plastics campaigner at Friends of the Earth, said, “Microplastic has been found in our rivers, our highest mountains and our deepest oceans.”
Like ocean acidification and sea surface warming, plastic pollution is a global problem that, to be solved, requires fundamental changes to our economy and culture. Cleanup efforts are important, but as long as plastic is made, particles and chemicals will leach out into natural environments. We need to understand—and address—the impacts that plastic has on ecosystems and on ourselves. But ultimately, we need to keep pursuing alternative materials to stop this pollution at the source.
I’m not saying don’t buy Halloween candy, but let’s all be conscious of the impact that Halloween has on marine environments. Maybe spend a few minutes counting all the plastic you see while trick-or-treating this year – the costumes, the wrappers, the yard decorations – and think about how it can be improved for next year’s celebration.
Clayton Starr is a guest writer for Talking Fish. He is a recent graduate from Bowdoin College where he earned a bachelor’s degree in Environmental Studies and English with concentrations in Marine Science and Creative Writing. Clayton hopes to communicate science to spread understanding and, ultimately, to inspire climate action.