How Do Dolphins Help in Disarming Sea Mines?

Quck answer

Dolphins are trained to locate and mark sea mines by using their natural sonar abilities. They are able to distinguish between mines and other objects in the water and can communicate their findings to their handlers. Once a mine is located, the dolphin will indicate its location by returning to its handler and signaling with a specific behavior. The handler can then send a team to disarm or remove the mine. This technique has been used successfully in various military operations and is considered to be a safe and effective way to protect ships and divers from the dangers of sea mines.

Wild Animals

A trained dolphin from the US Navy shows off its right flipper for the camera while leaping. Check out more pictures of dolphins.
U.S. Navy/Getty Images

Throughout history, animals have been loyal allies to humans during wars. Horses, for instance, have helped soldiers in combat, whereas dogs are still being trained to guard sites, find explosives, and conduct search and rescue missions. However, there is another animal that assists the military by working underwater, where horses and dogs cannot go.

Undersea mines have caused numerous ships to sink or get damaged since World War II. In fact, mines have been responsible for more ship damage than all other causes combined, such as active enemy attacks [source: Babb].

Recognizing their friendliness, trainability, and affection for humans, the U.S. Navy has been training bottlenose dolphins (and some sea lions) since the 1960s to find explosive mines underwater, as well as other suspicious objects and swimmers. Although they do not technically disarm mines, the dolphins locate the mines for humans to disarm or avoid them.

By rewarding the dolphins with fish, the Navy has trained them to spot suspicious metal objects made by humans from a distance. The dolphin learns to search for a mine and, when it finds one, swims back to the boat to poke an appropriate signifier, such as a ball, with its nose. The humans then provide the dolphin with a buoy or a special device called an acoustic transponder, which the animal leaves in the area where it has spotted the mine. This device produces a distinct sound that helps human divers find it later.

This photo of a mine and torpedo-finding dolphin was taken in 1973.
Evening Standard/Getty Images

The Navy can equip dolphins with cameras and sensors, but it is their natural abilities that make them perfect for the job. Unlike the mechanical devices that the Navy builds to detect mines, dolphins can differentiate between natural and man-made objects, a skill that is valuable because enemies cleverly disguise mines. Dolphins have an incredibly sophisticated sonar ability (using their sense of hearing) to perceive objects in even very murky water. This ability is so advanced that human technology has not yet been able to replicate it.

Keep reading to learn more about the sonar power of dolphins.

A Dolphin’s Sonar Abilities

Bottlenose dolphins use echolocation to spot objects from far distances in murky waters.
Stuart Westmorland/The Image Bank/Getty Images

Sonar is short for sound navigation ranging. It involves using and interpreting sounds to detect something’s location underwater, and is particularly useful for two reasons: water bodies are often too murky to see and sound travels faster underwater than in air.

Sonar technology sends out sounds and waits for them to bounce off other objects and return (similar to an echo in a cave). This technology is called active sonar, as opposed to passive sonar, which involves listening to the sounds of other active objects. Remarkably, sonar can interpret essential information, such as the exact distance of enemy submarines.

Dolphins have the ability to use biosonar, which is a skill that humans do not possess. They have been using this skill for thousands of years, making them very skilled at it. Their ability to differentiate between small objects from a distance is built into their DNA, which allows them to distinguish between a BB gun pellet and a kernel of corn from 50 feet away. Dolphins use echolocation, which is the same process used by bats and some whales. They emit clicks and squeaks that are too high for humans to hear, and these clicks act as active sonar mechanisms. When the clicks bounce back to the dolphin as an echo, it absorbs the returning echo through its jaw and conducts the sound to the dolphin’s inner ear. Scientists are unsure how a dolphin’s brain interprets sonar information, but studying them could help improve our own sonar technology. However, using dolphins for mine-finding purposes raises ethical concerns. Additionally, dolphins are prone to getting caught in nets because the nets do not reflect their biosonar clicks, which can be prevented with new nets equipped with a plastic beacon.

The Navy states that using dolphins for mine-hunting is safe for the animals. The dolphins are not trained to approach the mines, but rather detect them from a safe distance using their strong sonar skills. Furthermore, mines are designed to detonate only when large ships come into contact, not when disturbed by marine life. However, animal rights groups still object to the practice, particularly the transportation process which can be stressful for the dolphins and weaken their immune systems. The Navy maintains that their dolphins are well taken care of, with staff veterinarians available at all times. Canaries were also used in coal mines to detect noxious gases before the development of detectors.

Additional Information

Related Articles from HowStuffWorks

• Explanation of Landmines
• Explanation of Submarines
• Facts About Dolphins
• Explanation of Search-and-Rescue Dogs
• Explanation of Police Dogs
• How the World Wildlife Fund Operates
• Explanation of Torpedo Engines Underwater
• Definition and Function of Dynamite
• Quiz on Marine Mammals

More Useful Links

• AnimalPlanet.com
• “Sentinels of the Sea” Documentary on Pentagon Channel
• SeaWorld’s Explanation of Dolphin Echolocation
• PETA

Sources Cited

• “The sound of shapes.” Economist, Dec. 21, 1996, Vol. 341, Issue 7997, p.118-119, 2p, 1c.
• Babb, Colin. “ONR and NOAA Participate in Deep Partnership.” U.S. Navy. May 30, 2008. (June 27, 2008)http://www.navy.mil/search/display.asp?story_id=37381
• Bechtel, William, et al. “A Companion to Cognitive Science.” Blackwell Publishing, 1998. (June 27, 2008)http://books.google.com/books?id=eBw7dVcsTnMC.
• Gasperini, William. “Uncle Sam’s Dolphins.” Smithsonian.com. Sept. 1, 2003 (June 27, 2008).
• Jean, Grace. “Dolphin’s Brain Holds Secret to More Sophisticated Sonar.” National Defense. April 2008. (June 27, 2008).http://www.nationaldefensemagazine.org/issues/2008/April/Dolphin.htm
• Ransford, Matt. “Saving Dolphins with Sonar.” Popular Science. March 19, 2008. (June 27, 2008).http://www.popsci.com/scitech/article/2008-03/saving-dolphins-sonar
• Squatriglia, Chuck. “Dolphins hunt for mines in gulf waters.” SF Gate. March 27, 2003. (June 27, 2008)http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2003/03/27/MN291465.DTL
• Texas A&M University. “Flipper As Rambo: Dolphins Can Be Great Naval Security Tools.” ScienceDaily. April 11, 2003. (June 27, 2008)http://www.sciencedaily.comВ­ /releases/2003/04/030411070405.htm

FAQ

1. What are sea mines and why are they dangerous?

Sea mines are explosive devices that are placed in the ocean to destroy ships, submarines, or other underwater vehicles. These mines are dangerous because they can cause serious damage to the vessels passing over them, leading to loss of life and property. Sea mines are also difficult to detect and disarm, making them a major threat to naval forces and commercial shipping.

2. How do dolphins help in disarming sea mines?

Dolphins are trained to detect and mark the location of sea mines in the ocean. They are equipped with special sonar devices that allow them to locate the mines, and they are trained to swim back to their handlers and indicate the location of the mine by touching a marker with their nose. This enables human divers to safely approach the mine and disarm it without risking injury or death.

3. How are dolphins trained for this task?

Dolphins are trained to locate and mark sea mines through a process of positive reinforcement. They are taught to associate the location of the mine with a reward, such as a fish or a toy, and are gradually trained to indicate the location of the mine to their handlers using a marker. The training process can take several months, and requires a high level of expertise and patience from the trainers.

4. Are there any risks to using dolphins in this way?

While the use of dolphins in mine detection has been successful, there are some risks involved. Dolphins can be injured or killed by the explosion of a mine, and they can also be harmed by exposure to environmental toxins and pollution in the ocean. There is also concern about the ethical implications of using animals for military purposes, and some groups have called for an end to the practice.

5. How effective are dolphins at disarming sea mines?

Dolphins have proven to be highly effective at locating and marking the location of sea mines. They are able to detect mines that are too deep or too far away for human divers to detect, and they are able to do so quickly and accurately. The use of dolphins has also been shown to be more cost-effective than other methods of mine detection, such as sonar or underwater robots.

6. Are there any other animals that can be used for mine detection?

Other animals, such as sea lions and dogs, have been trained for mine detection, but dolphins are the most effective due to their advanced sonar abilities and their ability to dive to greater depths. Sea lions are also used for mine detection in some countries, as they are able to detect the electrical signals emitted by some types of mines.

7. What other tasks can dolphins perform for humans?

Dolphins have been trained to perform a wide range of tasks for humans, including assisting with search and rescue operations, detecting underwater explosives, and even providing therapy for people with disabilities. They are highly intelligent animals with advanced communication skills and have been shown to be capable of learning complex tasks with the right training and support.

8. Are dolphins endangered?

Several species of dolphins are considered to be endangered due to pollution, habitat loss, and overfishing. It is important to protect these animals and their habitats to ensure their survival and the survival of the ecosystems they inhabit. The use of dolphins for mine detection should be done with caution and with consideration for the welfare of the animals involved.