The Plastisphere, Marine Snow and Ocean Plastics

What is Marine Snow and The Plastisphere, and What Do They Have to Do with Your Health?

Hand of young woman uses sieve to collect microplastic at ocean beach

I run across all sorts of interesting phrases in my work as an environmental science writer. For our story about “How Pathogens Can Hitch a Ride on Plastic to Reach the Sea,” two new-to-me phrases caught my ear: Marine snow, and the Plastisphere.

So what are they?

The Plastisphere

The Plastisphere is a diverse microbial community living on bits of plastic floating in the ocean. These communities are distinct from the surrounding water, suggesting that plastic serves as its own habitat in the ocean. The term was coined in 2013 by scientists from Marine Biological Laboratory, Woods Hole Oceanographic Institution and Sea Education Association.

“It’s like a biofilm—a sticky material that traps all sorts of microorganisms, protozoa and fungi. They can multiply and create a unique biome around the plastics,” said UC Davis Karen Shapiro, who studies how protozoan parasites move in the environment, including water. Her interests led her to study how pathogens on land could use microplastics to “hitchhike” throughout the ocean.

What is marine snow?

Marine snow is a term popularized by scientific explorer and diver William Beebe in the 1930s. It’s made up of nutrient-rich, organic material that falls like snow from the ocean’s surface to the sea floor.

Particles of plastic drift under blue water in the ocean
Particles of plastic and other debris float in the ocean. (Getty)

“The marine snow phenomenon explains why there’s life at the bottom of the ocean,” Shapiro said. “Also, how carbon can move from top to bottom in the ocean can also be partly explained through marine snow.”

Marine snow is a natural and beautiful phenomenon that can enrich ocean life. But when plastic is thrown into the mix, Shapiro’s research from 2014 showed that marine snow can also capture parasites like toxoplasma gondii and move them throughout the ocean, trapping it in the biofilms of kelp forests, where sea otters, who are vulnerable to the disease, are often found.  

4 things you can do 

What can you do about it? Whatever you can to reduce your use of plastic. We listed some key ways in "Plastic 'Pool' Toy Pollution in the Wild." They include:

  • Keep items full of microbeads and glitter away from natural waterways, and reduce plastic use in general. If you do bring a pool float to the beach, choose something that won’t easily rupture, and make sure it returns home with you. 
  • Be a conscious consumer and consider the life cycle of plastic. Your day at the beach could leave a lasting mark on the environment. 
  •  Be clothes-conscious. Microfibers from clothes — and laundry machines — often make their way into waterways. Buying clothes made from natural fibers, like cotton, rather than synthetic material can reduce the amount of microfibers entering lakes, rivers and oceans. Doing laundry less often can also lighten the microfiber load on waterways, and on your housework.
  •  Think reusable. Bringing your own reusable bag while shopping, using reusable water bottles, and choosing reusable storage containers over single-use plastic bags also continue to be more sustainable options.   

“It’s easy for people to dismiss plastic problems as something that doesn't matter for them, like, ‘I’m not a turtle in the ocean; I won’t choke on this thing,’” said Shapiro. “But once you start talking about disease and health, I feel like there’s more power to implement change.”

Media Resources

Kat Kerlin is an environmental science writer and media relations specialist at UC Davis. She’s the editor of the “What Can I Do About Climate Change?” blog. @UCDavis_Kerlin

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