VIDEO: Biological debris that falls from higher in the water column is also known as marine snow. Some flakes fall for weeks before finally reaching the ocean floor.

As plants and animals near the surface of the ocean die and decay, they fall toward the seafloor, just like leaves and decaying material fall onto a forest floor. In addition to dead animals and plants, marine snow also includes fecal matter, sand, soot, and other inorganic dust.

The decaying material is referred to as “marine snow” because it looks a little bit like white fluffy bits. The “snowflakes” grow as they fall, some reaching several centimeters in diameter. Some flakes fall for weeks before finally reaching the ocean floor.

This continuous rain of marine snow provides food for many deep-sea creatures. Many animals in the dark parts of the ocean filter marine snow from the water or scavenge it from the seabed. NOAA scientists and others have measured the amount of useable material in marine snow and found that there is plenty of carbon and nitrogen to feed many of the scavengers in the deep sea.