Rescuers struggled on Thursday to save dozens of stranded dolphins in shallow waters off the Florida Keys, with many volunteers standing in water for hours to support the animals. In total, about 110 of the rough-toothed dolphins arrived on sand flats near Marathon, south of Miami, on Wednesday night, said Blair Mase, regional coordinator for strandings at the National Marine Fisheries Service. About 25 swam out again to the ocean and four died. The others were still being supported by animal rescuers and volunteers in shallow water or had been taken into deeper water in a fenced-off canal area where they could swim freely. Mase said rescuers were waiting for results from blood tests on the animals to find out about their health and whether the dolphins would be candidates for rehabilitation or release. Rescuers did not know yet what pushed this group too close to land, but Mase said rough-toothed dolphins were highly sociable. That made them "common mass-stranders -- if one or two are ill, the rest will follow them." --SP 2304 Local Time 2004 GMT