Photo Credit | NOAA Office of Ocean Exploration and Research, Windows to the Deep 2019
Red, white, and blue: A squid (Magnoteuthis magna), common below 1,000 meters (3,280 feet) along the Northeastern coast of the United States, drifts along in the water column.
When we think of snow, we usually think of winter. But did you know that it is always snowing in the ocean? Marine snow isn’t the kind you can sled on — this continuous underwater snowfall sustains life in the deep sea and helps regulate Earth’s climate.
WHAT IS MARINE SNOW?
Marine snow is made up of tiny flakes of biological material — like dead plankton, fecal pellets, and organic matter — that slowly sink to the seafloor from the top layers of the ocean. As these “snowflakes” fall, they grow, sticking to other pieces of debris like decaying and dead animals. This steady cascade delivers carbon, nitrogen, and other nutrients to deep-sea creatures.
WHAT ROLE DOES MARINE SNOW PLAY IN THE OCEAN ECOSYSTEM?
Marine snow is an important food source for animals that live deep in the ocean. Sunlight never reaches the ocean’s deep waters, but marine snow does. Many animals in the ocean’s depths filter marine snow from the water or scavenge it from the seafloor as their primary food source.
Marine snow also plays a critical role in fighting climate change. As organic particles sink, they carry a small but significant amount of carbon down to the seafloor. This is part of a natural process that removes carbon from the atmosphere and stores it in the deep ocean for centuries. And less carbon in the air means a more stable temperature on Earth.
ARE THERE THREATS TO MARINE SNOW?
Plastic pollution is one big threat. Tiny pieces of plastic, called microplastics, can make marine snow more buoyant and slow its descent to the deep sea. This could cause less carbon to reach the seafloor and reduce the ocean’s efficiency in storing away carbon dioxide removed from the atmosphere.
Ocean acidification poses another risk. The ocean has become approximately 30% more acidic since the industrial revolution began, and estimates based on business-as-usual emission scenarios show that the ocean’s surface waters could be nearly 150% more acidic by the end of this century. Research shows that warming and acidifying waters may release some of the carbon that marine snow has helped store for millions of years back into the atmosphere.
WHY THIS MATTERS
Marine snow is vital to ocean life and climate stability, but its future depends on the choices we make now. Oceana is working to protect deep-sea habitats and keep our oceans healthy. Join us and become a Wavemaker today.
