NEW ORLEANS - (from right) Rear Adm. Roy Nash, commander of the Eighth Coast Guard District and Department of Homeland Security Secretary Janet Napolitano shake hands during a tour of the New Orleans port, Aug. 8, 2011. The Coast Guard provides oversight of the Mississippi River port system, which is among the largest in the world. U.S. Coast Guard photo by Petty Officer 3rd Class Stephen Lehmann.