GULF OF MEXICO - Coast Guard Petty Officer 3rd Class Juan Patino, a marine science technician, prepares a fluorometer in the Gulf of Mexico, May 27, 2010. Patino and crew will use the fluorometer and other instruments to collect water samples and field data which help environmental scientists determine the effectiveness of dispersants used to break down oil. U.S. Coast Guard photo by Petty Officer 2nd Class Luke Pinneo.