for National Geographic News
The hundreds of thousands of American, British and other forces stationed in the Persian Gulf region are currently employing some rather unusual allies in the battle to depose the Iraqi leadership.
A crack troop of United States Navy-trained dolphins were at work this week, helping to locate potentially lethal and obstructive anti-ship mines, littering the seafloor near the port of Umm Qasr and other locations.
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The Navy's Special Clearance Team One from San Diego, California, comprises platoons of human divers, unmanned underwater vehicles and intensively trained bottlenose dolphins. Dolphins' unrivalled underwater sonar abilities, and great intelligence, make them uniquely suitable for locating mines in cluttered shallow-water environments where military electronic hardware is rendered virtually useless.
"Dolphins have the best sonar on this planet the Navy does not have any technological sonar that can find buried mines except for their dolphin system," said Whitlow Au, who studies marine bioacoustics at the University of Hawaii's Marine Mammal Research Program in Kailua. "They can not only find objects like mines that may or may not be buried into the seabed, but they can distinguish them from clutter such as coral rock, and man-made debris," he said.
Sailor's Best Friend
In order to make way for ships carrying humanitarian aid and other vessels, the dolphins are "clearing sea mines in the harbor at Umm Qasr and potentially other places," said Tom Lapuzza, spokesperson for the U.S. Navy Marine Mammal Program at the Space and Naval Warfare Systems Center in San Diego, where more than 20 dolphins are based.
In return for fish rewards, the animals use echolocation to search for mines on the seafloor, said Lapuzza. Upon detection of a possible mine, the animals notify their military handlers, who choose whether to send the animals back with an acoustic transponder. These transponders, which are carefully dropped nearby, can be used by human divers to locate and destroy the munitions.
Dolphins use vocalizations as a kind of biological radar to scope out the surroundings. Objects hidden from sightsuch as fish or minesare revealed, when high- or low-frequency clicking sounds are bounced back in the dolphin's direction. Dolphin sonar is incredibly precise. "They can pick out objects like you wouldn't believe," said Lapuzzaeven down to detecting different types of metal, for example.
Though military gadgets for detecting mines work well in the open ocean, they can't cope with the amount of reverberation from clogged and cluttered harbor floors. Dolphins, on the other hand, have sonar "developed over 50 million years of evolution," precisely to work in shallow water environments, he said.
In addition, dolphins are obviously much better at working underwater than humans, said Mike Fedak, a marine mammal biologist at the University of St. Andrews in Fife, Scotland. Dolphins "cover a lot of ground fast are very bright, very adaptable, and extremely trainable," he said, adding up to a package the Navy has found hard to resist.
Dolphins, however, are not the only marine mammals currently stationed in the gulf. Navy-trained California sea lions were also shipped in from San Diego prior to the conflict.
While the animals lack sonar, they do posses superb directional underwater hearing and the ability to see in near-darkness. Sea lions are used by the Navy to retrieve submerged objects, and have also been trained to locate enemy divers, attach restraint devices or markers, and make a speedy getaway.
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