October 4, 2013
Robotic Jellyfish Shredder Takes On Growing Marine Menace
[ Watch the Video: A Battle Between Robot And Jellyfish ]
Brett Smith for redOrbit.com - Your Universe Online
Besides being a menace to swimmers and surfers in the ocean, jellyfish disrupt fishing nets, clog water intakes, feed on fish eggs and disrupt ecosystems with their massive swarms.
A team of engineers from the Korea Advanced Institute of Science and Technology (KAIST) has devised a new robotic system called JEROS that is designed to combat this sea-faring menace by sucking in the gelatinous organisms, grinding them up and spitting them back out as benign goo.
The aquatic robot has a mountable grinding mechanism that is kept afloat by two cylindrical bodies with propulsion motors. These motors move JEROS forward and in reverse, and allow it to rotate 360 degrees. The robot uses a computerized mapping system in its quest for jellyfish extermination. After the system calculates the desired path, JEROS autonomously traverses its course using a GPS receiver and an inertial navigation system.
To efficiently purge jellyfish from an area, the robotic killers establish a formation pattern. The system uses this method to eliminate the need for individual control of the robots. Only the lead JEROS needs a calculated path, as the other robots are programmed to follow in a formation by ‘talking’ to each other through a wireless communication network.
Field tests have shown that each robot is capable of moving at speeds of up to 4 knots (4.5 mph) and can exterminate jellyfish at the rate of almost 1 ton per hour.
Researchers from KAIST say JEROS technology could eventually be adapted for other purposes, including ocean patrols, mitigating oil spills and waste removal.
It should be noted that the gruesome prospect of shredding jellyfish en masse may not even remove the menace. When jellyfish of the genus Mnemiopsis are quartered, the four sections regenerate as full-bodied adults within 2 or 3 days. One particular jellyfish, known as the “Benjamin Button jellyfish,” even spawns new jellyfish from its dead carcass.
As if to demonstrate the menace that they are, jellyfish forced the shutdown of a nuclear reactor in Japan earlier this week. A jellyfish jam in the pipes at the Oskarshamn nuclear plant forced operators to close the plant’s third reactor twice in one weekend after a giant swarm of the gelatinous organisms gummed up the plant’s water intake pipes which bring cooling water to the reactor.
“It's true that there seems to be more and more of these extreme cases of blooming jellyfish,” Moller said. “But it's very difficult to say if there are more jellyfish, because there is no historical data.”
The Swedish fish researcher noted that there is a critical lack of jellyfish tracking information for scientists trying to solve to problem of proliferating jellyfish blooms.
Some researchers have asserted that the increasing number of blooms has been caused, in part, by human activity. If humans are indeed causing climate change, we would be creating longer and more robust algal blooms, which jellyfish feast on. Additionally, many fishing operations are depleting populations of sea turtles, one of the jellyfish's most voracious natural predators.