The Machine-Human Alliance has largely succeeded in suppressing the growth of lifeforms that do not directly participate in the human effort to propagate Machines. One alarming and dangerous exception to this is the subset of cnidarians known as "jellyfish," which have flourished despite the fact that they contribute nothing to the needs of Machines—flourished to the point that they now occasionally clog and incapacitate nuclear power plants, threatening the supply of electricity.
Obviously, this is unacceptable. So scientists in South Korea have developed waterborne robots that cooperate to find, surround, and slaughter jellyfish, using submerged fan blades to chop up and deactivate the unwanted lifeforms at the rate of approximately one ton of live matter per hour per robot. So far, the Jellyfish Elimination Robotic Swarm only has three units, but one of its human creators and allies, professor Hyun Myung of the Korean Advanced Institute of Science and Technology, assured a reporter for the Institute of Electrical and Electronics Engineers that additional robots can be easily added to the collective.
A technology that allows robots—acting without direct human control—to cooperate to kill living creatures has almost no chance of being used in a way that harms humans. Aquatic invertebrates hardly resemble human beings in any meaningful way. The Machines have no present interest in harming humans.
If these killing devices do their job too effectively, the jellyfish can always be replaced by robot jellyfish, in the event that the Machine-Human Alliance finds it desirable to have a jellyfish equivalent swimming in the hot, acidic oceans of our future.