falls through the oceans and settles on the sea floor in the same way
that it settles out of the air and accumulates on furniture. But the
dust in the ocean teems with life. Ocean dust, known by oceanographers
and scuba divers as marine snow, helps clean the surface layer of the
ocean. Scientists believe it may also bring important nutrients into
the deep sea, carrying with it diverse populations of microorganisms.
Mary Silver, a professor of ocean sciences at the University of California
at Santa Cruz, calls an ocean dust particle a"buzzing micropolis of
In the movie Titanic, marine snow is obvious. In scenes
where the small submarine explores the sunken ship, floating white particles
cloud the water.
"Most people think, 'Ah, that's pollution,'" explains
Silver, one of the first to study marine snow. But the marine dustballs
are bits of dead animals and plants and, as Silver describes it, "anything
that's out there, all tumbled together." On these dustballs, tiny organisms
live, eat and sometimes reproduce. The snow also serves as food for
bigger creatures, such as fish.
On the wall outside of Silver's laboratory hangs a
magnified photo of a snow particle. Near it is a photo of ordinary dust,
a bit of fluff scrounged from under a file cabinet or lab bench to make
a comparison. The two dustballs look like siblings.