Daily Times

Days after 215 whales died following a mysterious beaching event, another pod of 240 pilot whales has lost their lives after being stranded on New Zealand’s Pitt Island in the Pacific Ocean. While most of the whales died naturally, the Department of Conservation said that the surviving whales were euthanised.

The whales were euthanised due to threats of them being consumed by sharks, if they were refloated into the waters, apart from the heavily logistical issues on the island which is inhabited by less than 100 people.

“This decision is never taken lightly, but in cases like this, it is the kindest option. The conservation department does not try to refloat whales in the area due to the risk of shark attack to both humans and whales,” Dave Lundquist, marine technical advisor at the Department of Conservation, told Reuters.

The pod of whales has been found on the Chatham Islands archipelago, which lies about 840 kilometers off the east coast of New Zealand’s South Island. The archipelago consists of Pitt Island and Chatham Island with minimal human presence. The Chatham Island stranding occurred on Saturday, and also involved surviving pilot whales being euthanised.

Why does whale beaching happen?

Whale beaching is one of the most mysterious events in marine science, which is yet to be decoded by marine biologists. Scientists speculate that the reason could be the sociable nature of whales and dolphins that live in colonies. They travel together in pods, often following a leader, and are known to gather around injured or distressed whales.

While some suspect it could be a misguided leader of the pack, others speculate a misadventure, where a few animals get themselves into trouble and the rest of the group might follow them. Other researchers have also cited changes in electromagnetic fields in the region due to solar flares or seismic activity for the beachings.

It is to be noted that pilot whales use sophisticated sonar to find prey and for orientation, changes in the electromagnetic field could lead them in the wrong direction and away from the waters. Another reason, specific to the island, could be the tides and the shape of the beaches, where if whales or dolphins are caught in the waters, they are bound to be pushed towards the shore and stranded.

A 2019 research indicates the eating pattern of the whales in the region. The analysis of stomach contents from 114 long-finned pilot whales stranded at four locations around Tasmania between 1992-2006 revealed that they were eating a variety of squid. It indicated that the prey could have been closer to shore, drawing a few members towards the beach and the pod followed.

Recent beaching tragedies — While the October beaching event has killed over 400 pilot whales, a similar event happened just weeks ago in September when 230 whales were stranded on Tasmania’s west coast in Australia. Earlier, 14 sperm whales were discovered on King Island, part of the state of Tasmania in the Bass Strait between Melbourne and Tasmania’s northern coast.

Two years ago, about 470 long-finned pilot whales were found beached on sandbars off Tasmania’s west coast in the largest mass stranding on record in Australia.

The largest mass stranding in modern recorded history happened in 1918 when 1,000 whales were stranded on the shores of the same Chatham Islands where the latest tragedy has happened.

Whales are a protected species, even once deceased, and it is an offense to interfere with a carcass.