Every night, swarms of tiny crustaceans swirl up from the bottom of the oceans to feed on algae at the surface. Although each individual organism is only a centimetre or two long, the collective motion of migrating columns of krill, brine shrimp and zooplankton may play an important role in ocean mixing, according to new research out of Stanford University.

Ocean mixing is the process by which heat, energy and nutrients like nitrogen, silica and phosphorous are redistributed throughout the layers of the ocean. The process plays a role in regulating the climate and creating the marine plant life upon which many species depend for food. Until recently, scientists shrugged off the idea that marine animals had any impact on this mixing, but the results of the Stanford study show the nightly migration of swarms of crustaceans may have an effect greater than the sum of their parts.

“If you have some small force mixing the oceans, then it could cascade into major impacts,” says Isabel Houghton, lead author of the study, which was published in the journal Nature on April 18.