Dolphins Stranded In Florida Keys

Four dolphins stranded off the Florida Keys have died and dozens were being treated for dehydration Thursday as veterinarians tried to determine why they came to shore.

More than 96 rough-tooth dolphins were found on flats and sandbars and in a nearby canal Wednesday about a quarter mile off Marathon, officials said. At least 60 animals remain stranded.

Dozens of volunteers from various marine agencies worked all night in chilly water to help save the dolphins, reports CBS station WFOR. More than eight rescuers were treated for hypothermia.

By Thursday, most of the dolphins had been moved from just a few inches of water on the flats to the 15-foot-deep, mangrove-lined canal, said Denise Jackson, a member of the Marine Mammal Rescue Team.

"Some are free swimming and frolicking and having a good time," she said.

Boats brought most of the dolphins to the canal, though one hitched a ride on a stretcher in back of a pickup truck, Jackson said.

Veterinarians were conducting blood tests and other medical assessments on the dolphins.

"We're looking to see if they've got any sickness going through them," Jackson said. "We're looking at their levels of dehydration, which will tell us how much they have been eating, if they have been eating."

Marine mammals may strand when they are sick, injured or disoriented, said Laura Engleby, a biologist with the National Marine Fisheries Service.

Rough-tooth dolphins normally inhabit deep, offshore waters in the Gulf of Mexico and the Atlantic Ocean, she said.

"They're not a coastal species," Engleby said.

Marathon is on Key Vaca, in the middle of the Florida Keys about 45 miles east of Key West. The dolphins were stranded on the ocean side of the island.