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196

sea snow

OLogy Series
biology
card
196

sea snow

OLogy Series
biology

Throughout the world's oceans, tiny particles swirl, drift, and fall like snowflakes from the ocean's upper levels. Appropriately named "sea snow," these particles are made of debris, or dead parts of plants and animals, along with other organic stuff such as sand and poop! Sea snow provides food for many marine animals. It also acts as a transport system, carrying matter from the sunlit surface to the deep seafloor.

Depending on their size, particles of sea snow sink from the ocean's surface to its depths over the course of days. Smaller particles fall:

more slowly than larger particles

faster than larger particles

at about the same speed as larger particles

Are you right?

Correct!

Smaller particles of sea snow tend to fall more slowly than larger particles because of the viscosity of water.

Sometimes sea snow is so thick, divers can see only a few feet in front of them. These conditions are sometimes called a:

sprinkle

thunderstorm

blizzard

Are you right?

Correct!

Large amounts of sea snow are sometimes called a "blizzard."

Bacteria eat "flakes" of sea snow.

Fact
or
Fiction
?

Fact

Bacteria do help to break down sea snow.

Also known as: marine snow
Description: tiny, nonliving particles that sink in the ocean
Size: particles at least 0.5 millimeters in diameter
Found; in every ocean of the world
First person to study sea snow: marine biologist Mary Silver from the University of California, Santa Cruz

Image credits: courtesy of REVEL Project, University of Washington.