Four pilot whales that had been stranded on a Massachusetts beach have been euthanized, according to conservationists.
The health of the whales had "greatly declined" after three days of being stranded, with the whales initially being lifted by the high tide but then getting stranded again, Stacey Hedman, communications director for the International Fund for Animal Welfare's Marine Mammal Rescue and Research team, told ABC News. The weather and the exhausted state of the whales contributed to the grim outlook for the large mammals, Hedman said.
"The team made the difficult decision to euthanize these animals as we knew rescue efforts at this stage were no longer going to be possible," Hedman said. "It's the most humane decision to make in a circumstance like this."
The whales "passed quickly," Hedman said, adding that they are still searching for one remaining whale.
Six pilot whales were initially spotted swimming close to shore near Sunken Meadow Beach in Eastham, Massachusetts, on Monday afternoon, prompting stranding experts form the International Fund for Animal Welfare's Marine Mammal Rescue and Research team to respond to the scene to check on their well-being, Hedman said.
By Tuesday morning, the whales had become stranded on the beach, and one -- a calf -- had died, Hedman said. After the whales were briefly examined, and two were given satellite tags, the conservationists hoped the high tide in the afternoon would help push the marine mammals back into the ocean.
The five remaining pilot whales were re-floated and released shortly after the tide came in, but by 6 p.m. Tuesday, four of the whales had turned back toward shore, and rescue efforts were temporarily put on hold, the organization said.
"The five pilot whales swam off well in one direction together, but the reality is that we cannot celebrate a success yet this evening," Misty Niemeyer, stranding coordinator at IFAW, said in a statement. "One animal is now offshore, but the others did not follow."
The conservationists monitored satellite tag hits overnight, and a field team was able to locate the majority of the animals about 2 miles north near the Mass Audubon Wellfleet Bay Wildlife Sanctuary in Wellfleet, Massachusetts, Hedman said. One whale is now offshore, she added.
The team is evaluating the next steps, Niemeyer said, describing the rescuers as "exhausted" after their strenuous efforts Tuesday.
"Large animals can be quite dangerous to work around, and it's for our health as well as tomorrow's continued efforts that we need to call it a day today," she said late Tuesday.
Teams of rescuers were responding in phases Tuesday to provide supportive care until the tides were more favorable, Hedman said.
Video taken on the scene showed crews digging up sand around the whales, some of which were covered in wet blankets to help them retain moisture. Some of the whales were also administered fluids via IV to help combat the stress and shock of stranding, Sharp said.
Dolphins and small whales can indeed live out of water for many hours when receiving proper supportive care and hydration, Hedman said.
While Cape Cod is considered a global hotspot for live cetacean stranding, historically, pilot whales do not strand there, Hedman added.
IFAW typically transports dolphins to deeper water using a custom-built rescue vehicle, but the whales are too big to transport, according to the organization.
But some of the animals are "very large," with the largest estimated to weigh about 4,000 pounds -- making them too heavy to transport, Brian Sharp, director of the research center, said in a recorded statement.
"This is tough on all of our responders," Hedman said. "We were cautiously optimistic and put a tremendous amount of work into this effort. If you were there, you likely felt our hopefulness as the whales first swam off at the end of the day yesterday."