Many of the whales were already dead, but the remaining ones had to be euthanized to minimize their suffering because they could not be put back into the water, the department added. That operation ended Wednesday, it said.
“This is a sad event for the team and the community,” Dave Lundquist, a technical adviser to the conservation department, said in a statement, adding that representatives of tribes that inhabit Chatham Island “were present to support” the department’s efforts. “Many people” were “affected” by the terrible scenes, he said.
Some 200 whales died just two weeks ago after stranding themselves on the west coast of Tasmania, an Australian island southeast of the mainland.
Efforts to save the whales that were not already dead when they washed up on the Chatham Islands were made more difficult by the archipelago’s remote location and the predators roaming the waters that surround it, the department said.
“We do not actively refloat whales on the Chatham Islands due to the risk of shark attack to humans and the whales themselves, so euthanasia was the kindest option,” Lundquist said.
Experts don’t always know why whales wash up on land, but it’s a relatively common occurrence that can also affect other marine animals such as dolphins. A “mass stranding” involves at least two animals, unless it involves a mother and calf. Pilot whales in particular are “prolific stranders,” according to the conservation department.
The largest mass stranding recorded on the Chatham Islands involved nearly 1,000 whales and happened more than 100 years ago, the department said.
The archipelago is extremely remote — it takes about two hours to fly from New Zealand’s capital, Wellington, to Chatham Islands Tuuta Airport — and “limited communications and challenging logistics” make operating there difficult, the department added.
When whales that strand themselves are not already dead or seriously injured, conservationists will in some cases work to “refloat” them into the water. This involves keeping the whales cool and wet on land to stabilize them before carrying them back into the ocean using tarpaulins or large floating platforms.
Because pilot whales are social mammals, their instinct is to stay with their pods; they might collectively strand themselves in an effort to help one injured whale or beach themselves even after they are refloated if they hear a whale’s distress call from land.
“So even when you got some animals successfully into deeper waters, it’s not uncommon for them to turn tail and come straight back in,” Karen Stockin, a marine biology researcher at Massey University in New Zealand, told The Washington Post in 2020.
In September, 32 whales were refloated outside Macquarie Harbor in Tasmania after the stranding there. The island’s Parks and Wildlife Service said several of them re-stranded that night. It said it would work to “re-float and release the remaining live whales.”
Lundquist said Wednesday that “all the stranded pilot whales are now deceased, and their bodies will be allowed to decompose naturally.”
“These events are tough, challenging situations,” the conservation department’s Chatham Islands team said in a statement. “Although they are natural occurrences, they are still sad and difficult for those helping.”