Iran threatens to shut the Strait of Hormuz, the U.S. Navy has a backup arrangement to save one-fifth of the world's daily oil trade how send in the dolphins The threat of Iran closing the channel has reached a fever pitch, with U.S. officials warning Iran's supreme leader that such moves would cross a "red line" provoking a U.S. reaction.Iran could attempt to block the strait with any assortment of mines, armed speed boats or anti-ship cruise missiles but according to Michael Connell at the Center for Naval Analysis,
“The immediate issue [for the U.S. military] is to get the mines.”
To solve that problem, the Navy has a way out that isn't heavily-advertised but has a time-tested winner rate: mine-detecting dolphins.
These animals were used during the Iraq war. There was uncomfortable warning with the news on the Navy's use of the lovable mammals that said in a situation like the standoff in Hormuz, Navy-trained dolphins would come in handy but risky.
The invasion of Iraq was the last time the mine sweeping capability of dolphins was widely-touted. "Dolphins - - which possess sonar so keen they can discern a quarter from a dime when blindfolded and spot a 3-inch metal sphere from 370 feet away -- are invaluable minesweepers," reported The San Francisco Chronicle.
In 2010, the Seattle Times reported that the Navy has 80 bottle nose dolphins in the San Diego Bay alone. They are taught to hunt for mines and drop acoustic transponders nearby. According to a report in 2003, the dolphins only detect the mines. Destroying them is left up to the Navy's human divers. Still, the mammals are large enough to detonate a live mine, a prospect that doesn't delight animal rights groups. 
