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Hunting for Mines

U.S. Navy ships operating in the Persian Gulf face an unseen threat from underwater mines. Iraq laid several thousand in the first Gulf War, and military officials are also concerned about mines set by terrorists. In the past, the United States has been criticized for avoiding the dull and dangerous job of hunting mines. But as NPR's Eric Niiler reports, the Navy is trying to catch up, using everything from underwater robots to dolphins.

Since World War II, 14 U.S. ships have been sunk or damaged by mines, while only two have been sunk by enemy fire. Sitting underwater until they're detonated by the sound of a passing ship, mines are cheap and effective. Robert Martinage, a senior defense analyst at the Center for Strategic and Budgetary Assessments in Washington, says mines are used by more than 50 nations, and new technology is making them harder than ever to detect.

During the Gulf War, Iraq blocked U.S. Marines from landing by stringing the Kuwait shoreline with mines. In deeper water offshore, mines also severely damaged two U.S. warships. After the war, minesweepers removed 13,000 mines from the Persian Gulf. But military officials say some may still remain.

An expert panel from the National Academy of Sciences found in 2001 that the United States was largely unprepared to deal with mine warfare. Since then, Navy researchers have rolled out several kinds of underwater robots designed to look for mines along shorelines or in harbors and send back data before U.S. ships arrive. The Navy's newest mine-hunter looks like a 5-foot-long torpedo and can be dropped over the side of a small boat.

These robots have already been used to look for terrorist mines around ships docked in San Diego and Norfolk, Va. But they still have their limits, says Thomas Swean, program director at the Office of Naval Research in Alexandria, Va.

"One of the things you're worried about is fishing nets, they'll grab you," says Swean.

Unmanned vehicles also have trouble communicating underwater, and analyst Martinage says most of them only have enough power for about a day.

The new machines aren't the only solution; the Navy also uses marine mammals. For 30 years, the Navy has been training dolphins to find objects on the seafloor and mark them with a floating buoy. So far, the dolphins are more reliable than the unmanned robots, says Navy Commander Melanie Branson of the Pacific Third Fleet in San Diego, Calif.

"Basically they work alongside a boat, they have a handler, and they work for fish," she says.

Despite years of protests by animal rights' groups, Navy officials say the dolphins are well taken care of and are not put in harm’s way.

Trained dolphins detected World War II-era mines off the Norwegian coast last year and even guarded the Navy's flagship in Bahrain in 1986 and 1987. But one thing robots and dolphins can't do is destroy the mines they find. That's left to the Navy's human divers, many of whom have already been sent to the Persian Gulf.

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Eric Niiler
Eric Niiler reports for NPR's national desk. His work can be heard on All Things Considered, Morning Edition, and other NPR newsmagazines. Before moving to his current post, Niiler was a reporter for NPR's Day to Day program, and also filed pieces for NPR's national and science desks.