Everyone is familiar with security patrol dogs. You may even know that because of their exceptionally keen sense of smell, dogs like beagles are also used to detect drugs and bombs, or land mines. But a dog would not be effective in finding a sea mine. Sea mines are sophisticated, expensive weapons that are designed to work in the ocean where they can sink ships, destroy landing craft, and kill or injure personnel. Sea mines are made so that they cannot be set off easily by wave action or marine animals growing on or bumping into them. If undetected, sea mines can be deadly, destructive weapons.
But just as the dog's keen sense of smell makes it ideal for detecting land mines, the U.S. Navy has found that the biological sonar of dolphins, called echolocation, makes them uniquely effective at locating sea mines so they can be avoided or removed. Other marine mammals like the California sea lion also have demonstrated the ability to mark and retrieve objects for the Navy in the ocean. In fact, marine mammals are so important to the Navy that there is an entire program dedicated to studying, training, and deploying them. It is appropriately called the Navy Marine Mammal Program (NMMP).