Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff Lauren Vogelbaum here. Animals, for better or for worse, have a long history as faithful allies to humans in war zones. Perhaps the most notable of the battlefield animals is the horse, which throughout human history has aided soldiers during combat, and to this day, militaries still train dogs to guard sites and soldiers a find explosives, and conduct search and rescue. But still another animal aids the military by going where
dogs and horses can't. Underwater undersea mines have been responsible for sinking or damaging many ships. Since World War II, more ships have been damaged from mines than from all other causes combined, including active enemy attacks. Beginning in the nineteen sixties, the US Navy's Marine Mammal Program started training bottlenose dolphins to find explosive minds under water as well
as other suspicious objects. The dolphins don't disarm or explode the mines, but rather locate the mines for humans to subsequently disarm or mark for avoidance, all without putting the dolphin in any substantial danger. Trainers using fish as a reward and ignoring incorrect behaviors teach the dolphins to spot suspicious man made metal objects from far away. A dolphin learns to search for mines, and, upon finding one, swims back up to the trainer's boat to poke an appropriate
signifier like a ball, with its nose. The humans then give the dolphin a boy or a special device known as an acoustic transponder, which the animal leaves in the area where it spotted the mine. An acoustic transponder produces a distinct sound that allows human divers to find it later.
During the Cold War, the then classified Marine Mammal Program had over a hundred dolphins in its service, locating minds and other objects, delivering equipment to divers, and even helping guard vessels by alerting crude to potential threats like swimmers who might be looking to plant explosives. Though the Navy can equip dolphins with cameras and sensors, it's really the dolphins' natural abilities that make them perfect for jobs like mind detection.
Unlike the mechanical devices that the Navy builds to detect minds, dolphins can easily tell the difference between man made and natural objects, and invaluable skill given mind makers can craftily disguise them. Dolphins have a remarkably sophisticated sonar ability, using their sense of hearing to perceive objects in even very murky water. This ability is so evolutionarily honed that human technology hasn't come close to replicating it. Sonar is short
for sound navigation and ranging. It's a method of using and interpreting sounds to detect the location of something, especially in water, where it's handy for two reasons. First, bodies of water are often far too murky for sight, and second,
sound travels well underwater. After all, sound travels by vibrating particles, and the particles in water are much denser than the particles in air, so water allows sound waves to move faster and for longer distances without degrading a Sonar technology works by sending out sounds and waiting for the sounds to bounce off of other objects and come back the same way that an echo bounces back to us in
a cave. This technology is called active sonar, as opposed to passive sonar, or simply listening for the noises of other active objects. With sonar, we can interpret vital informations such as exactly how far away enemy submarines are Humans have been using sonar for over one hundred years, but dolphins have been at it for millennia. The tricks of sonar are built into their DNA, so much so that they can tell the difference between a beepy gun pellet
and a kernel of corn from fifty feet away. A dolphin's sonar process, but also used by bats and some whales, is called echolocation. If you've ever heard a dolphin, you'll immediately recognize its characteristic clicks and squeaks. But there's more than meets the ear, and many of the noises they make are at frequencies too high for the human ear to detect. Essentially, dolphins use these clicks as active sonar mechanisms. A dolphin's echolocation process goes like this. The dolphin uses
its nasal passages to make a series of clicks. The sound waves travel through its forehead, which contains a fatty organ called the melon that focuses and directs the waves as they move out into the water. When the sound waves hit an object in the water, they bounce back to the dolphin as an echo. The dolphin absorbs this
returning echo through its lower jaw. Another passage of fat in the jaw conducts the sound to the dolphin's inner ear, which then exchanges nerve impulses with the brain to interpret the object's characteristics such as size, shape, and material. One way to think about the echolocation process is to imagine you're in a pitch black room with only a flickering
flashlight to guide you. To help understand an object, a dolphin will move around it and read it from multiple points of view, as you might in the dark room, as well as with varying kinds of clicks. They'll even adapt for noisy environments by adjusting the frequency of their clicks. Using this process, dolphins can determine the size and shape of objects, and even in some cases distinguish different metals such as brass and copper from far away, which assists
them in finding minds. However, this has also been why in the past dolphins were so prone to getting caught in fishing nets. The nets traditionally didn't seem to register to dolphins using sonar to navigate. Newer nets are equipped with shell shaped plastic beacons that reflect and amplify a collocation signals to help prevent these accidents. Researchers aren't sure
how a dolphin's brain interprets sonar information. So much of our human understanding relies on visual information that it's hard for us to wrap our minds around the idea of seeing objects so specifically with our ears. Because dolphins are so good with sonar, studying them hopefully will help us improve our own sonar technology, and the Marine Mammal Program has funded all kinds of research into these and other
marine animals physiology, health, behavior, and sensory systems. Thanks to this and other research, underwater drones are improving all the time, but the dolphins' capabilities are still unmatched, and the Marine Mammal Program persists to this day. Then has used bottlenosed dolphins and sometimes California sea lions as security agents, detecting swimmers and divers around vessels during the Vietnam War, the
Gulf War, and beyond. The program was mostly declassified and heavily downsized in the nineteen nineties, but out of a base in San Diego, the Navy still trains both dolphins and sea lions as guards a plus the dolphins for mine location and the sea lions for equipment location and recovery. The sea lions can be trained to attach recovery lines to found equipment. Of course, using animals to do military
work comes with a lot of questions. How are they cared for and how safe and satisfied are they during missions and transport. The Navy maintains a staff of trainers and veterinarians who administer daily preventative health care as well as regular exams, and they run mobile clinics that travel with the animals during deployment. Nting process is much safer
for the dolphins than it might sound. Dolphins aren't trained to get close to a mine, but rather to sense it from a safe distance, and if the dolphins were to happen close to a mine, it shouldn't explode. Mines are not built to detonate when disturbed by marine life, but rather by large, heavy ships. If animals the size of dolphins could detonate a mine, the mine would explodes soon after being planted, a rendering it useless as a
weapon against enemy ships. Still, animal rights groups find fault with the program. Deployment can mean transportation via ships, cargo planes, or trucks. The Navy uses special enclosures to keep the animals safe, but distance travel can be inherently uncomfortable, even for humans who understand what's going on. Plus, the waters that the animals are deployed into are unfamiliar environments, potentially with fairly different water conditions than what they're used to.
There are regulations in place about things like temperature changes, but all of this could be a source of stress for the animals, which could have a negative impact on the animal's health and well being. Also, when an animal is retired, what happens then. Although a few of the program's animals have just left, they are trained partially in
open waters, so they have that option. It's generally not recommended to release animals into the wild that are comfortable with humans and have come to rely on human provided food and shelter. Some retired dolphins have found homes in marine sanctuaries. Others have been kept in the Navy's care. From the other side of the Cold War, some of the Soviet Navy's dolphins originally trained for military operations have
been retrained as therapy animals for children. In the end, animal activists question, is it ever okay to use creatures that are completely ignorant of the danger involved in war. Is there any benefit to human life that can excuse removing wild animals from wild environments or at least from adapted sanctuaries. Is the benefit that the animals receive from guaranteed food, shelter, and socialization worth it? These are complicated questions.
If you'd like to learn more about the Marine mammal program, you can visit the United States Naval Undersea Museum online or in person in Keyport, Washington, or for personnel with base access in San Diego, you can schedule a tour through the Connaissance and Interdiction Division. Today's episode is based on the article how can dolphins disarmed Sea Mindes on HowStuffWorks dot Com, written by Jane mcgrat. Brain stuff It is a production of iHeartRadio in partnership with how stuffworks
dot Com and is produced by Tyler Klang. For more podcasts from my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.