The Great Barrier Reef's Best Hope Is a Killer Robot

Crown-of-thorns starfish are the zombies of the sea. They won't die even if you cut them in half. To kill one, you must dismember it completely--or inject it with poisonous (to them) bile salts. Instead of braaains, these zombies munch coral, and off the coast of Australia, infestations of the beasts are damaging the Great Barrier Reef at an alarming rate. In development since late 2014, the underwater droid identifies and assassinates the ravenous stars--autonomously.