A group of 145 whales was discovered strewn across a beach in New Zealand after the most recent incident of whale stranding in the country.,

The pilot whales were found by a hiker on the remote island of Mason Bay late on Saturday. According to authorities, half the whales had already died by the time they arrived, while the other half were euthanised.

“Sadly, the likelihood of being able to successfully refloat the remaining whales was extremely low. The remote location, lack of nearby personnel and the whales’ deteriorating condition meant the most humane thing to do was to euthanise,” Ren Leppens, an operations manager at the New Zealand’s Department of Conservation, said in a statement. The department also shared aerial footage of the whales on the shore.

New Zealand authorities said whale stranding or beaching – a phenomenon in which whales and dolphins strand themselves on land – is not uncommon in the country, but in most cases it is a single whale. The possible reasons behind the phenomenon, according to experts, might be navigational errors, sickness or pursuit by predators.