Six of the 41 whales died overnight and four more were euthanized during the day.
Efforts were under way to try to coax the surviving whales back to deeper water, the Miami Herald reported.
"Pilot whales are a particularly cohesive species, which is why they tend to mass-strand," Blair Mase of the National Oceanic and Atmospheric Administration said. "There may be members of their group that are ill and beach themselves, and the other whales stick with the pod and remain in the area."
Pilot whales grow to 12-18 feet long, weighing 1-3 tons.
"Given the scenario of where the dead whales are and our inability to move them off shore, the outcome of this situation may not be good," Mase said. "We want to set realistic expectations for the public. We don't know how long these whales have been out of their normal habitat."
Mase said necropsies were being performed on the dead animals in hopes marine experts will learn why the whales beached themselves, CNN reported.
Fishermen spotted the beached whales Tuesday night in the Highland Beach area.
Everglades park spokeswoman Linda Friar said the whales were believed to have approached the beach -- miles from deeper water -- at high tide, but were unable to leave when the water level dropped.
Phillip Clapham, director of the whale research program at the National Marine Laboratory in Seattle, said it is not uncommon for whales to beach themselves, CNN said.
"These events, while they're tragic, don't have any implications for the survival of the species," he said.