More than 145 whales die together on a remote island's beach after two pods strand themselves – but no one knows why

About 145 pilot whales stranded themselves on a remote New Zealand beach
Two pods of whales at Masons Bay, Stewart Island, were discovered by a hiker
There are theories but not a definitive answer to why whales beach themselves


The pilot whales were found by a hiker at Mason Bay on Stewart Island, off the southern tip of New Zealand's South Island on Saturday.

WHY DO WHALES BEACH THEMSELVES?
In short noone knows but theories include:

Navigational errors: Gently sloping coastlines and food rich ocean currents close to shore can lead to confusion.

Toxic algae blooms: Along with viruses can cause mass sickness in pods and the animals may be too sick to swim.

Shipping and military sonar interference: This can scare the animals and cause distress and even decompression sickness as they swim to the surface.

Mass suicides: There is little evidence to support this theory.

https://www.dailymail.co.uk/news/article-6427981/More-145-whales-die-remote-island-beach-two-pods-strand-themselves.html

I always find this very disturbing.