This article originally appeared on VICE US
Within a week, nearly 200 whales have perished in two mass strandings on New Zealand beaches.
On Thursday, 51 pilot whales died after washing up on shores near the town of Owenga in the remote Chatham Islands, on the heels of another devastating stranding on Saturday that killed 145 whales on Stewart Island.
Many of the whales died before rescuers could reach them. Some of the beached survivors managed to successfully return to the sea, but about half of the Stewart Island stranders had to be euthanized. One of the beached Chatham Island whales also had to be put down.
“I’ll never forget their cries, the way they watched me as I sat with them in the water, how they desperately tried to swim but their weight only dug them deeper into the sands,” wrote Liz Carlson, a travel writer who discovered the Stewart Island stranding and alerted authorities, on her Instagram page. “The realization we could do nothing to save them was the worst feeling I have ever experienced.”
Both Stewart Island and the Chatham Islands are known stranding “hotspots” for pilot whales, according to the New Zealand Department of Conservation. These whales, which are the second largest member of the dolphin family after orcas, travel near these shores in tight-knit pods during the summer in the Southern Hemisphere .
Scientists think that when they venture inland to feed, the shallow coastal waters confuse their echolocation and navigational senses. This might explain why New Zealand pilot whale strandings peak during its warmest months, from November to March.
New Zealand’s coastline may be particularly deadly for pilot whales, but they also frequently wash up elsewhere—within the past week, for instance, 29 pilot whales died in strandings on Australian shores.
Pilot whales suffer from mass strandings more frequently than any other whale. According to NOAA, this species might be uniquely vulnerable because they are extremely social and if one whale strands, others may follow it although not necessarily for the same cause of stranding.
The largest stranding on record occurred in 1918, when over 1,000 pilot whales washed up and died on the Chatham Islands. More recently, in February 2017, 252 pilot whales died in a particularly harsh stranding near Cape Farewell on New Zealand’s South Island.
The bodies from the most recent whale strandings will be buried with help from local Maori communities.