This CNN report shows how the U.S. military is planning to use dolphins to mark or locate underwater mines in the Strait of Hormuz. Known as the MK4 Marine Mammal System, the dolphins have been trained to find mines sitting on the ocean bottom, buried in sediment or where marine plants make it difficult for Navy machines to explore.
The Navy used fish rewards to train dolphins to spot manmade, metal objects from a distance. The dolphin learns to search for a mine through echolocation, swim back up to the boat and poke a ball with its nose to let divers know it has found something. The humans then give the dolphin a locating device, sush as an acoustic transponder, which the animal leaves near the mine. This device produces a distinct sound that allows human divers to find it later.
The dolphins ability to detect underwater objects using echolocation makes them perfect animals to find mines. According to the CNN report, dolphins could be airlifted to the Strait of Hormuz if the Navy suspects mines have been placed there.