More than 30 long-finned pilot whales were shot in the head and killed Thursday after repeated attempts to refloat the stranded marine mammals in a bay at the north of New Zealand's South Island.
Volunteers had twice refloated the surviving whales from the pod of 99 only to have them restrand on tidal flats at Farewell Spit in Golden Bay.
Department of Conservation area manager John Mason told the New Zealand Herald that 33 whales were shot in the head with a high-caliber rifle shortly after the decision to put them down at 8:15 a.m. Thursday local time.
He said the decision was made after the whales began showing "significant" signs of physical deterioration and stress, with many bleeding and blistering in the morning sun.
"We don't believe anything more could be achieved," he said.
Only 17 whales of the 99 survived the stranding, which began Monday.
Last November, 65 pilot whales were stranded in the same area, with 21 already dead when they were discovered. Six more later died and the remaining whales were put down when it became clear they would also not survive.