Masses of shrimp and krill may play a huge role in mixing oceans
The swimmers’ turbulence could be powerful enough to stir nutrients up from the deep
MIXING IT UP One swimming brine shrimp generates small-scale turbulence (time lapse of suspended particles in green). But large numbers of the animals together may create currents that stir oceans.
Isabel Houghton
When it comes to tiny ocean swimmers, the whole is much greater than the sum of its parts. Ocean turbulence stirred up by multitudes of creatures such as krill can be powerful enough to extend hundreds of meters down into the deep, a new study suggests.
Brine shrimp moving vertically in two different laboratory tanks created small eddies that aggregated into a jet roughly the size of the whole migrating group, researchers report online April 18 in Nature. With a fluid velocity of about 1 to 2 centimeters per second, the jet was also powerful enough to mix shallow waters with deeper, saltier waters. Without mixing, these waters of different densities would remain isolated in layers.
The shrimp represent centimeter-sized swimmers, including krill and shrimplike copepods, found throughout the world’s oceans that may together be capable of mixing ocean layers — and delivering nutrient
