Just because the oil was cleaned up from the beaches doesn't mean it's gone.
The opposite is true, a University of South Florida professor says. In fact, he estimates cleanup work along Panhandle beaches and elsewhere across the Gulf Coast has removed only about 25 percent of the oil that has stained the shorelines.
"Twenty-five percent is pretty generous,'' said Ping Wang, an associate professor of geology at USF. "I stand behind my numbers.''