Despite covering 71 percent of the Earth’s surface, our oceans still remain a great unknown for science. Only five percent of the sea floor has been topographically mapped, meaning the moon and some celestial neighbors like Mercury and Venus are better known than our own ocean. But understanding the sea around us is vital for securing our future on this planet, and a handful of scientists have made it their mission to illuminate the deep.
Among the most prominent of these scientists are Jules Jaffe and Peter Franks, researchers from the Scripps Institution of Oceanography at the University of California San Diego. In a recent paper, Jaffe and Franks describe a study they conducted with a swarm of grapefruit-sized robots called Miniature Autonomous Underwater Explorers (M-AUEs), which ride currents and monitor their environment in 3D. Data collected by the swarm has already offered insight into the lives of plankton, the oceans most abundant life form.
To measure oceanic properties, the specially designed M-AUEs are fitted with temperature sensors and buoyancy controls that enable them to adjust their relative depth and monitor how ocean currents influence marine life. Though the paper published January 24 in the journal Nature Communications depicts a swarm of 16 M-AUEs, the researchers suggest that hundreds or thousands of these machines could be deployed in a massive swarm to answer more complex questions.
“The numerous drifters in the swarm each behave independently, reacting to changes in their environment through pre-programmed movements of their piston, which controls their buoyancy,” Franks told Digital Trends. “The distributed elements of the swarm acted like a large-scale sensing system, allowing us to record changes in the swarm size in response to the underlying ocean currents.”
The researchers wanted to test a theory of plankton movement that Franks proposed twenty year ago. But such a test required them to track the movement of individual organisms in the ocean, which is impossible with current technologies. Jaffe designed the M-AUEs to mimic how plankton move, using acoustic signals to track the devices.
The swarm’s data revealed the accuracy of Franks’ original prediction. The research confirmed that free-floating plankton can exploit the ocean’s physical dynamics to gather in patches that Franks likens to “planktonic singles bars” since the organisms use them for both reproduction and feeding.
The researchers plan to scale down the size of their units and beef up their swarm, building hundreds more units to help monitor events like red-tide blooms and oil spills with better accuracy.
