, is releasing a report Aug. 17 showing that chemical dispersants may have caused a share of the oil to sink to the ocean floor, where some of it has been found at the bottom of an underwater canyon 40 miles (65 km) south of the Florida panhandle. That could have an effect on bottom-dwelling plankton that form the base of the marine food chain. The USF researchers also raise questions about the possibility that the sunken oil could float up again in the future.</p><p>But the scientists from UGA come at thei