The BBC reports this week that the US Navy is looking to replace its fleet of specially trained sea mammals with mine-detecting robots. For nearly 50 years, the Navy has been using dolphins and sea lions to detect, and sometimes defuse underwater mines, as part of its Sea Mammal Program. But this program will be phased out by 2017, as officials turn to more mechanized (and cost-effective) alternatives, such as the Knifefish underwater drone.

Announced earlier this year, the Knifefish is a torpedo-shaped unmanned underwater vehicle (UUV), measuring some 20 feet in length. The vessel is still in development, though officials say that by 2017, it should be able to roam underwater for up to 16 hours, using sonar to identify any mines. The Navy also plans to introduce a German-developed system known as SeaFox, which can actually defuse underwater mines — a task that has long been delegated to human divers.

"The Navy is very humane about the way they treat these animals."

The Navy acknowledges that sea mammals may still be called upon to perform some missions beyond 2017, since even advanced robotics can't quite match the sonar capabilities that dolphins possess, though its new fleet of drones should be able to perform these tasks at a much faster rate — and, most important, for much less. Unlike bomb-sniffing dogs, dolphins demand substantially more care, and must be transported within special enclosures abord Navy ships. They also require veterinary staff to be onboard at all times, which adds extra financial strain.

But the Navy won't just leave its mammalian helpers out in the cold, either. Captain Frank Linkous, head of the Mine Warfare Branch, tells the BBC that all dolphins and sea lions will be under special care after they leave the force. "The Navy is very humane about the way they treat these animals," Linkous says. "Essentially, these animals have a pension – they are cared for the rest of their lives."