In a new public service announcement unveiled today, Mayor Joe Jaworski assures visitors that Galveston's beaches remain clean, safe and open after state and U.S. Coast Guard officials announced the discovery of tar balls from the BP Deepwater Horizon spill. Officials traced tar balls found on Bolivar Peninsula and Galveston’s East Beach during the weekend to the spill, which resulted from an April 20 explosion that killed 11 crew members aboard the oil rig Deepwater Horizon. The condition of the tar balls leads officials to believe they arrived in ship ballasts, not on ocean currents. Galveston's tourism officials want visitors to know there is no loose oil or oil sheen on or near Galveston's shoreline. "During peak season, it is vital for Galveston’s economy to continue with a successful summer," the Galveston Convention and Visitor's Bureau said in a statement. "This year the island is offering new special events and additional exhibits to its attractions to ensure guests are offered a variety of options for their summer vacation. "The public service announcement featuring Mayor Jaworski’s message was created to support tourism on Galveston Island as well as to ensure guests that the situation is being closely monitored."