Churning water by the numbers

Small ocean dwellers may play more of a role in climate than what would appear at first glance; in fact, scientists in Nature magazine said that the effect that these small animals have on a macroscopic scale is comparable to that of winds and tides. Scientist thought that the turbulence created by small jelly fish or shrimp-like copepods would dissipate almost instantaneously, but swimmers may also drag fluids with them, which has nothing to do with "generating a wake." As krill move from the depths closer to the surface, they drag with them cold water--in accordance with physics on fluid motion can corroborate--which mixes with warmer water above. A team of scientists in the south pacific tried to test this mechanism by inserting a dye where jellyfish would swim, and the water did move along with more viscous small jellyfish. Not only do these water-critters cary water with different temperatures, but they also carry carbon with them, an important factor in climate in the oceans. As much as a trillion watts of energy was transported via sea creatures.

Most of this article speaks about discovery based science, in which observations were collected. However, as more knowledge about the nature of fluids and their interaction with small swimmers, hypotheses led to experiments, such as that of the dye mentioned above, which proved the importance of ocean critters in climate.

from Science News