51 pilot whales die in another stranding

WELLINGTON, New Zealand — Fifty-one pilot whales died on Friday in another mass stranding in New Zealand, less than a week after 145 pilot whales and nine pygmy killer whales perished in two other, unrelated strandings.

In the latest stranding, up to 90 pilot whales beached themselves late on Thursday at Hanson Bay on the remote Chatham Islands, said the Department of Conservation.

When staff arrived at first light, they said they found up to 40 of the whales had refloated themselves but another 50 had died on the beach. The department said one beached whale remained alive, which staff decided to euthanize due to its poor condition.

The Chatham Islands are around 800 kilometers east of New Zealand’s main islands and are home to about 600 people.

Last weekend, 145 pilot whales died on Stewart Island. By the time conservation experts arrived there, around 75 of the whales were already dead and they decided to euthanize the others by shooting them due to their poor condition and remote location.

On Sunday, 10 pygmy killer whales were found stranded at Ninety Mile Beach on North Island.

Despite the best efforts of 200 staff and volunteers, who managed to refloat eight of the whales after transporting them to a beach where conditions were calmer, all but one of them ended up stranding themselves again by Wednesday. Those whales were also euthanized.

Dr Dave Lundquist, a technical adviser on marine species, said in a video released by the Conservation Department that there was no evidence to suggest the strandings were linked.

“You’re talking about strandings across the entire breadth of New Zealand in a very short period of time, which naturally does cause everyone to reflect on whether those might have something to do with one another,” he said.

Lundquist said that while scientists don’t typically know why individual whale strandings occur, they believe there are probably a range of reasons. He said they could be caused by the whales navigating incorrectly, trying to escape from predators, or some of them suffering injuries or illness. He said there could also be man-made factors like underwater noise.

“In many of those cases, it’s probably a combination of those factors,” he said.

Karen Stockin, a marine mammal scientist at Massey University, said while whale strandings were relatively common in New Zealand, the cluster of incidents in such a short time frame was unusual.

Stockin said New Zealand was currently experiencing some of the warmest ocean temperatures on record and she believed it was affecting whale behavior.

“We’ve had an unusual week, which we haven’t got to the bottom of, and it’s fair to say it’s been an entirely unusual year,” she said. “I suspect a lot of that has been driven by the warmer sea surface temperatures that we’re seeing at the moment.”