Remember sea monkeys, the little packets of dried brine shrimp eggs that would inevitably die within days of hatching? Like most zooplankton, they migrate vertically in groups in response to changes in light, rising to the surface at night and retreating to darker depths by day. Now, researchers at Cal Tech have used lasers to show that this isn’t just a convenient tactic for the sea monkeys – their movements can have a huge effect on oceanic currents.

“This research suggests a remarkable and previously unobserved two-way coupling between the biology and the physics of the ocean: the organisms in the ocean appear to have the capacity to influence their environment by their collective swimming,” said researcher John Dabiri.

The experiment exploited what’s known as phototaxis, the brine shrimp’s tendency to gravitate towards a light source. They used a blue laser light and slowly raised it to the top of the tank holding the sea monkeys, while a green laser shone from above kept them from clumping to one side. Also in the tank were microscopic silver coated glass spheres. When captured with a high-speed camera, the tiny spheres allowed the team to visualize the movement of the current. The results where somewhat astounding.

While the movement of a single zooplankton created an insignificant disturbance in the water around them, the effect becomes magnified when two move together in concert. When many zooplankton coalesce into large groups, as in this experiment, the swirls they create could alter water circulation on a much larger scale.

Though winds and tides get much of the credit for the ocean’s currents, small organisms like brine shrimp shouldn’t be ruled out – because they make up the bulk of oceanic biomass, the researchers estimate their movements could generate up to one trillion watts of power within the ocean, putting them on par with the winds and tides. The next step will be to test the effect in a tank where the water’s density increases with depth, as it does in the real ocean.

“If similar phenomena occur in the real ocean, it will mean that the biomass in the ocean can redistribute heat, salinity and nutrients,” said Dabiri.