Military Dolphins and Sea Lions: What Do They Do and Who Uses Them?

Military-trained marine mammals, including dolphins, can detect underwater mines and intruders.

A trained bottlenose dolphin named K-Dog leaps out of the water during a training exercise in the Persian Gulf.

Russian activities in Crimea now include taking over a Ukrainian military unit made up of bottlenose dolphins, according to news reports.

It's unclear how the Russian navy intends to use these "combat dolphins," although state-run Russian news agency RIA Novosti reports that the mammals will be getting equipment upgrades.

Using marine mammals like dolphins, whales, or sea lions for military purposes isn't new. Nor is it restricted to the Ukrainian or Russian navies—the U.S. Navy has had a similar program since the 1960s. The ability of these animals to detect and find targets at depth or in murky water is something technology can't duplicate yet, but which militaries find very valuable.

The Sevastopol-based "combat dolphins" are trained to search for and tag underwater mines or unwanted divers or swimmers attempting to access restricted waterways, says RIA Novosti.

The U.S. Navy trains its marine mammals—including California sea lions and bottlenose dolphins—to find and retrieve equipment lost at sea and to identify intruders swimming into restricted areas. The dolphins are also used to detect underwater mines, either buried in the seafloor or floating from an anchor.

A beluga whale marks a training target.

Nothing Like the Real Thing

"[Bottlenose dolphins] are better than any machine as far as detecting mines," says Paul Nachtigall, head of the marine mammal research program at the University of Hawaii in Kane'ohe Bay. They can also do it much faster than a machine can.

Dolphins can be especially effective close to shore, where crashing surf and ship traffic generate a lot of noise, Nachtigall says. Mechanical systems can be overwhelmed by all the competing signals, but not dolphins.

It's because their sonar is so finely tuned, he explains. Dolphins, and relatives like killer whales, send out a series of sounds that bounce off of objects in the surrounding environment. The mammals pick up the return echoes and form an acoustic picture of their environment, an ability known as echolocation.

Experiments Nachtigall conducted in the mid-1990s with a resident bottlenose dolphin named BJ demonstrated this sensitive ability. Nachtigall asked BJ to distinguish between metal cylinders made of either stainless steel, brass, or aluminum. Even though he buried the four-inch-long (ten-centimeter-long) objects under two feet (0.61 meters) of mud, BJ passed with flying colors.

Researchers still don't know how dolphins do this, Nachtigall says. But it's a topic that has captured the attention of military and civilian scientists for decades.

Out of Place

California sea lions, while they don't possess sonar capabilities, have excellent eyesight. "They're really good at finding things that are out of place," such as lost equipment, says Nachtigall.

The U.S. Navy uses them to find and retrieve unarmed test ordnance like practice mines. Handlers give a sea lion an attachment system it can hold in its mouth and send the mammal overboard. Once the animal finds its target, it clamps the device to it and handlers in a boat at the surface can bring the object in.

A 2011 media demonstration in San Diego Bay, California, featured a former U.S. Navy SEAL attempting to infiltrate the harbor with an unarmed mine. The Navy deployed dolphins and sea lions to patrol the area, and both caught the diver on every one of his five attempts. The sea lion even managed to attach a clamp to the diver's leg, and handlers on the surface reeled him in like a fish.

Both California sea lions and bottlenose dolphins are fairly hardy, smart, and very trainable, says Nachtigall. Sea lions also have the advantage of being amphibious. That's why the U.S. Navy ended up using them instead of other marine mammals like false killer whales or belugas, which they also initially looked at. (See "Dolphins Have Longest Memories in Animal Kingdom.")

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