The crown-of-thorns starfish preys on coral reefs. One of the world’s biggest starfish, the spiky nightmare sprawls over the reef and pushes its stomach out through its mouth, covering and sealing the coral while it liquefies and digests it. All the while, its venomous spikes protect it from larger predators.
This starfish is a plague on reefs, carpeting and destroying them like loggers clearcutting rainforest. And because they’re starfish, they regenerate like a T1000 Terminator, growing back limbs that are cut off and generally surviving anything you throw at them. They’re especially a problem now because nutrient-rich runoff from rivers has caused their population to explode. And that means our reefs, which are really important, are threatened from starfish-based destruction.
Into this fray comes the COTSBot (Crown-Of-Thorns Starfish robot), the undersea equivalent of Arnold Schwarzenegger (to continue the Terminator metaphor), a submarine which hunts down crown-of-thorns starfish and administers a lethal injection, killing them as dead as would a bath in molten metal. The COTSBot “is designed to operate without a tether, and execute missions with minimal human interaction once deployed.”
Once launched, the 66-pound robot will cruise Australia’s Great Barrier Reef for six hours at a time, down to a depth of 330 feet. Using cameras and algorithms, it identifies crown-of-thorns starfish and moves in, hovering just long enough to lower a needle and pump poison (bile salts), at 10-times the lethal dose) into the starfish before moving on to continue the hunt.
The process is chilling in its ruthless robotic efficiency. The vision system is 99% accurate, and the poison, harmless to other sea creatures, causes “discolored and necrotic skin, ulcerations, loss of body turgor, accumulation of colorless mucus, loss of spines and large, open sores that expose the internal organs,” according to researchers at James Cook University. This color change means the submarine can easily spot already-executed starfish and avoid them, increasing efficiency still further.
Up until now, this work has been done by human divers which, apart from the whole underwater death part, makes for tedious work better done by drones. And this isn’t the first time we’ve seen death-dealing undersea robots. Jellyfish, too, are the target of the JEROS (Jellyfish Elimination Robotic Swarm), a terrifying device that hunts in packs, trapping jellyfish in a net before using its propeller blades.
It seems like a bad time to be an ocean-going pest.