Winds and Tides and Swimming Plankton Each Provide One Trillion Watts Of Power To Drive The Motion Of Ocean Waters
Swirling ocean pasture eddies are made and sustained by the very ocean life that inhabit those pastures. Gaia is smiling at it taking us so long to unravel one of her mysteries.
Every night the largest migration of life on Earth takes place in ocean pastures. It’s the nightly swimming of trillions and more tiny plankton critters swimming up to the surface to feed in the safety of darkness.
The tiny plankton critters most of which are no larger than a grain of rice are so abundant and so powerful that their swimming up each evening and down each morning drives ocean systems with the same power as the winds and tides.
The plankton we share this planet with are important… you might give their advice/plankton manifesto a read.
Researchers studied this in careful aquarium studies where they measured dial (day and night) vertical migratory behaviour in the lab as their captive specimens followed variations in light to move between the surface and the depths, churning the water in the process.
Think of ocean plankton as tiny living boats with a sustainable combined output of about 2 billion horsepower.
This time it wasn’t sharks using ‘frickin lasers’ but tiny plankton that were illuminated by lasers for the purpose of measurement.
Caltech engineering (home of TV’s Big Bang Theory geeks) and brilliant professor John Dabiri head of the Biological Propulsion Lab with graduate student Monica Wilhelmus hooked up lasers to guide their plankton pets upward and downward through a tank of water. In the wild, a vast number of related zooplankton rely on their sensitivity to light to tell them when to rise up and feed on algae at the surface during twilight, and then sink back down to avoid predators during the day.
Observations of laser-induced vertical migrations of their test specimens reveal the appearance of a downward jet. Such a downward jet in large ocean pastures is needed to trigger a “Kelvin-Helmholtz instability” that is needed for the generation of eddy-like structures with characteristic length scales much larger than the cloud of planktonic swimmers.
The measured energy spectrum is consistent with these findings and indicates energy input at large scales, despite the small individual size of the organisms. These results motivate the study of bio-mixing in the presence of stratification to assess the contribution of migrating zooplankton to local and global ocean dynamics.
So it seems the living biological mechanism is now proven to be more than capable of producing and sustaining gigantic ocean eddies which are in turn known to be the vital ocean pastures that sustain the very ocean life that help create and sustain the eddies. It’s almost magical and in fact it is the power of life on this living Blue planet.
“Coaxing Sea-Monkeys to swim when and where you want them to is even more difficult than it sounds,” Dabiri said in a news release. “But Monica was undeterred over the course of this project and found a creative solution to a very challenging problem.”
A green laser was positioned to provide a target for the shrimp (known by the scientific name Artemia salina), while a blue laser rising along the side of the tank lit up a path for the critters to follow.
The researchers filled the tank with tiny, silver-coated hollow glass spheres, each measuring less than a thousandth of an inch (13 microns) wide. The movement of the spheres was tracked using a red laser and a high-speed camera — and that showed how much energy the flapping of the Sea-Monkeys’ tiny fins added to water circulation in the tank.
Dabiri and Wilhelmus propose that trillions of oceanic zooplankton follow a similar sea-churning pattern every night. By their measure they propose that all that movement adds as much as a trillion watts of power to drive ocean circulation. In comparison, they say the combined energy input from the winds and tides at 2 trillion watts. So it appears that tiny plankton are an equally potent force to either the wind or tide.
Plankton Power Sustains Our Livable Planet
In previous work, Dabiri proposed that jellyfish movements could add to ocean circulation, playing a vital role in stirring up the sea’s nutrients and distributing heat.
“Now, these new lab experiments show that similar effects can occur in organisms that are much smaller but also more numerous — and therefore potentially more impactful in regions of the ocean important for climate.”
Dabiri predicts, this might help scientists model climate change more precisely. The ocean is Earth’s largest carbon sink, soaking up more than any other part of the world’s quarter of CO2 than any other. Zooplankton have been recognized as actively sustaining ocean pastures have now had one of their professional ocean steward stirring mechanisms revealed.
“We may need to rethink our models of the ocean,” Dabiri said. “Perhaps there are significant factors we’re missing right now.”
The obvious link of this work to our work of restoring vital ocean pastures is clear.
As ocean plankton life has been and continues to be decimated by our fossil CO2 their powerful ocean force for good that helps control our climate is destroyed.
We must work to restore and replenish ocean pastures and sustain plankton’s power that in turn sustains ocean life. Without thriving ocean plankton pastures we don’t have a chance.
Dabiri’s paper describing the experiment, “Observations of Large-Scale Fluid Transport by Laser-Guided Plankton Aggregations,” is published and freely available (click the link) in the journal Physics of Fluids. The research was supported by the U.S.-Israel Bi-national Science Foundation, the Office of Naval Research, and the National Science Foundation.
Additional reading on how ocean eddies might control climate change… uh oh… does this mean plankton eddy power might influence climate...