Sting operation: Undersea killing machines to make mincemeat of giant jellyfish

·3 min read
A diver encounters a huge Nomura's jellyfish off the coast of Japan. Rising numbers of jellyfish have long caused problems for fishermen, but a new 'extermination device' might have the answer
A diver encounters a huge Nomura's jellyfish off the coast of Japan. Rising numbers of jellyfish have long caused problems for fishermen, but a new 'extermination device' might have the answer

An underwater robot hunter has been built to seek out and destroy soaring numbers of jellyfish.

Jellyfish are proliferating at a rapid rate in some parts of the world, such as Japan, with sightings in British waters also becoming more common.

Such vast numbers of the animals pose a risk to the fishing industry because they get caught in nets, spoil catches and endanger crew and vessels.

With rising ocean temperatures and fewer natural predators, waters around Japan have in recent years been clogged with moon jellyfish and enormous Nomura’s jellyfish, which can grow to 6ft and weigh 440lbs.

So a team of researchers from Hiroshima Institute of Technology set out to create a 3ft-long, self-driving “jellyfish extermination device” to “suck and crush” the animals, before ejecting fragments of them back into the ocean.

The prototype was found to be highly competent at vanquishing the animals when tested in a laboratory. It will now be deployed in the wild in future experiments to see if it is able to hunt, hoover up and exterminate live populations.

The researchers wrote in the Journal of Japan Society for Design Engineering: “In this experiment, a jellyfish extermination device was mounted on [an] autonomous underwater vehicle, and a crushing experiment was conducted using a jellyfish sample which is made of water and gelatin.

“It was confirmed that a jellyfish sample with a diameter of about 7cm and a height of about 11cm could be crushed to small pieces, which has an average volume of 2,885.6mm cubed, during less than about eight seconds.”

The jellyfish sample used to test the machine's effectiveness
The jellyfish sample used to test the machine's effectiveness

The theory is that a robot can be carried by ships and deployed in the water with onboard ultrasonic sensors to track down marine life. AI is then used to determine if the target is a jellyfish.

When jellyfish are identified, a large-mouthed hose will suck the creature into the vehicle - where jets of highly pressurised water and a turbine will shred the animal to pieces.

The machine cut the jellyfish sample into small fragments
The machine cut the jellyfish sample into small fragments

Engineers are confident a version of the machine will be used in the oceans by 2024. They say it can operate at depths of more than 160ft for up to three hours, before returning automatically to its mother ship.

Early versions, such as the first of its kind prototype, will target moon jellyfish, which can grow up to 12 inches in diameter. If the prototype proves to be effective, larger robots could be deployed using the same techniques to go after much bigger jellyfish species, such as Nomura’s jellyfish.

“The robot will help to reduce the burden on fishermen, who have to manually remove jellyfish caught in their nets,” Ahn Jong-hyun, the assistant professor who is leading the team, told the Yomiuri newspaper. “In the future, we want to develop a robot that can exterminate giant Nomura’s jellyfish.”

Fisheries officials estimate that jellyfish cost the country’s industry more than £60 million a year, with thousands of reports of damage to fishing equipment every year.

Prof Martin Attrill, a marine ecologist from Plymouth, wrote in The Conversation last year that there were large numbers of lion’s mane jellyfish off the Scottish coast.

“This stunningly beautiful animal can be one of the biggest jellyfish in the world,” he said.

“The largest specimen recorded had a diameter of over 2m and tentacles trailing back nearly 37m from the main body, making it probably the longest animal in the world (a blue whale’s maximum length is 30m).”

Jellyfish blooms, which are linked to warmer waters and climate change, are also becoming more common in British waters.