The threat of Iran closing the strait has reached a fever pitch, reports today's New York Times, with U.S. officials warning Iran's supreme leader that such moves would cross a "red line" provoking a U.S. response. Iran could 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 solution that isn't heavily-advertised but has a time-tested success rate: mine-detecting dolphins.Article has lots of supporting links, so it's easier to check it out directly.