Wildlife workers had planned to use noises such as banging on pipes and revving boat engines to herd the whales out to the open ocean. But that turned out to be unnecessary, and the workers simply used positioning of the boats to prevent any of the whales from turning away from the open sea, Mase said.
Teams from NOAA, the National Park Service, the Coast Guard and state wildlife agencies were working to prevent any more whales from stranding. The animals had not been cooperating Wednesday, when most were in about 3 feet of water.
The short-finned pilot whale is known for its close-knit social groups: If one whale gets stuck or stays behind, the others are likely to stay or even beach themselves as well. Pilots are among the smaller of the whale species, with adult males reaching up to 18 feet in length and females 12 feet.
The species is also most commonly involved in mass strandings. According to NOAA, there was a stranding of 23 pilot whales at Fort Pierce, Fla., in September 2012 and one involving 23 whales at Cudjoe Key, Fla., in May 2011. The last one in the Everglades area was in 1995.
Federal officials were notified about the whales Tuesday around 4 p.m. Because of the remote location, workers were unable to access the site before dark. They arrived Wednesday morning and discovered 45 whales still alive.
“There were some that were very compromised and in very poor condition,” Mase said.
Federal officials euthanized four whales Wednesday, but no more were put down Thursday.
Mase confirmed Thursday that sharks had begun to feed on the dead whales. Necropsies were completed Thursday, and scientists will look for disease or other signs to indicate how the whales got stuck in the shallow Everglades waters.
“It may take weeks and weeks and even months to get those results back,” she said.