Creatures large and small may play an unsuspected important role in the stirring of ocean waters, according to a study.
So-called ocean mixing entails the transfer of cold and warm waters between the equator and poles, as well as between the icy, nutrient-rich depths and the sun-soaked top layer.
It plays a crucial part in marine biodiversity and, scientists now suspect, in maintaining earth’s climate. The research is published in the journal Nature.
The notion that fish and other sea swimmers might somehow contribute significantly to currents as they move forward was first proposed in the mid 1950s by Charles Darwin, grandson of the legendary evolutionary biologist of the same name.
But this was dismissed by modern scientists as a fishy story.
In the 1960s, experiments compared the wake turbulence created by sea creatures with overall ocean turbulence.
They showed that the whirls kicked up by microscopic plankton or even fish quickly dissipated in dense, viscous water.
On this evidence, sea creatures seemed to contribute nothing to ocean mixing.
The clear conclusion was that the only drivers of note were shifting winds and tides, tied to the gravitational tug-of-was within our solar system.