While it's a simple change of units story, it does point out that these units are providing protection for the oil terminals through which 90% of Iraqi GDP flows.
Caption: 050127-N-0401E-002 Persian Gulf (Jan. 27, 2005) - A Sailor assigned to Mobile Security Force Detachment Two Two (MSD-22) stands watch aboard Al Basrah Oil Terminal (ABOT). MSD-22 is providing security for Iraq’s oil terminals as part of a joint effort between United States and coalition forces to provide security against terrorist attacks to Iraq’s oil platforms. U.S. Navy photo by Journalist 1st Class Wes Eplen (RELEASED)
Caption: 041212-N-6932B-015 Persian Gulf (Dec. 12, 2004) - Hundreds of oil tankers each year receive their payload from Iraq’s Al Basrah Oil Terminal (ABOT). Mobile Security Force Detachment 22 (MSD 22) is currently defending Iraq’s oil terminals as part of a joint effort between U.S. and coalition forces to provide security against terrorist attacks to Iraq’s oil platforms in the North Persian Gulf. U.S. Navy photo by Photographer's Mate 1st Class Richard J. Brunson (RELEASED)
More on the Mobile Security Force here. During Desert Storm, Navy (Navy Reserve) Mobile Inshore Undersea Warfare Units and Coast Guard (Reserve) Port Security Units performed similar duties for Saudi terminals and ports...
Update: Fixed a error in the title. "Who's", not "Whose". I know better, but the gremlins don't.