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The Navy's Use of Dolphins & Sea Lions

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Since 1960, the U.S. Navy has conducted research on marine mammals in hopes of improving the speed and maneuverability of its vessels. In addition to the research component, the Navy's Marine Mammal Program also employs animals to conduct sensitive underwater tasks. While belugas, seals and orcas also have been used, the Navy primarily uses bottlenose dolphins and California sea lions because they're comparatively easy to train and adaptable to diverse marine environments.

Sea Mine Detection

Sea mines are complex explosive devices planted in the ocean for the purpose of sinking ships. By design, normal ocean waves and currents or sea mammals bumping into them won't cause them to explode. The Navy trains dolphins to locate sea mines using their sense of echolocation, which works like a powerful underwater sonar to detect obstacles or disturbances in the water. Once located, the Navy is able to avoid or safely remove the sea mine. Trained California sea lions also find mines and attach cables to them so they can be removed and detonated.

Surveillance and Defense

The Navy has used dolphins for underwater surveillance and defense since the Vietnam War, when dolphins were deployed to Cam Ranh Bay to protect a U.S. ammunition pier from enemy swimmers. Dolphins swimming around anchored vessels find deep-sea terrorists who may attempt to plant explosives. The dolphins tag the divers so the Navy can find and interrogate them. Sea lions' superb underwater vision and hearing capabilities also help the Navy detect enemy swimmers near ships or bases, even at night. In 1996, Navy dolphins even assisted the Secret Service to maintain the security of the San Diego coastline during the Republican National Convention.


The Navy's Marine Mammal Program faces harsh criticism from animal rights activists who object to the use of innocent marine mammals to carry out military operations. Although the Navy maintains it treats the marine mammals in its care humanely, critics note the animals often are housed in cramped enclosures and transported far from their home waters. In the late 1980s, the Navy scrapped plans to use dolphins to guard a missile base after activists filed suit, alleging the cold northern waters would damage the health of bottlenose dolphins originally captured in the Gulf of Mexico.

The Future of the Program

The Navy's Marine Mammal Program reached its pinnacle during the Cold War Era. The end of the Cold War brought a desire to downsize the expensive program, and in the early 1990s several military dolphins were donated to marine parks and sanctuaries. In 2012, the Navy announced plans to phase out the program entirely beginning in 2017, when robots currently in development will be available for deployment. These robots use sonar and can explore at depth underwater for as many as 16 hours. Of course, robots don't need food or medical care when they're not being used. The desire to replace the animals with machines was motivated in large part by the expense of keeping marine mammals.