Underwater Drone Swarms Used To Study Plankton Mating

Scientists had been having fun with drone swarms: first by making them dance in unison, and now, by making them swim underwater.

Before you hit your The Little Mermaid Rastafarian dance, thanks to Sebastian the Crab, it is for a far more serious issue. A group of University of California - San Diego researchers was able to build a set of 16 mini-autonomous underwater explorers (M-AUEs) to stay at a depth of 33 feet underwater, drifting laterally in any direction to track the motion of water below the surface.

Quartz noted that pressure sensors can help the robots maintain their depth. Also, the GPS is used to track their positions, using sound similar to that used in submarines. To measure the robots' positions, the team also deployed "pingers" that surround the area that the robots are in to improve tracking. As it is, GPS signals do not do very well in the water.

These robots, according to Quartz, track "internal waves," which are longer, shallower and slower than surface waves. They occur when the ocean has different densities at different depths. They may be subtle. But as Phys.org noted, they do prove to be important, as they are used by planktons to move and find each other.

Plankton are not strong swimmers, and many of their species are single-celled. Yet these tiny organisms will have to mate. How they do so is a mystery that scientists were not able to solve, until now.

Peter Franks, co-author of the study, shared that among plankton problems include mating. But with a lack of brain, this could be a problem. He said, "Picture two people blindfolded on a football field trying to find each other."

However, as the drones showed, when encountering internal waves, they ride over the crests and form clusters in the troughs, a form that Franks believes is similar to what planktons do to find each other in the vast ocean. He also noted that once they know where plankton go, scientists can better get a grip on how fast they renew after harvesting, leading to a better understanding in protecting many species underwater.