Around half a thousand pilot whales have died stranded on New Zealand’s remote Chatham Islands, the government said on Tuesday, after ruling out a rescue mission due to the multitude of sharks in the area.
Some 250 stranded pilot dolphins were found on Friday on Chatham Island, the largest in this archipelago, and about 240 on Pitt Island three days later, according to the same source. Due to the approximately 800 kilometers that separate this archipelago from New Zealand, a rescue operation was impossible, authorities said.
“Fearing a shark attack on humans and cetaceans, our team euthanized the surviving pilot dolphins to spare them further suffering,” technical adviser Dave Lundquist said.
“A decision like this is never taken lightly, but in cases like this it was the softer option,” he added. The bodies will be left on the spot. Such strandings are not unusual in the Chatham Archipelago, with the largest dating back to 1918, when a thousand pilot dolphins perished. Just over two weeks ago, around 200 pilot dolphins perished on a beach in Tasmania, Australia. Forty-four mammals had been released.
The causes of these major strandings are not fully known. These pilot whales, which can reach up to six meters in length, could veer off following a sick member of the herd. Bad weather conditions or the presence of predators could also force them to change their route.
Around 300 pilot dolphins are stranded in New Zealand every year, according to official figures. It is not uncommon for a single stranding to involve groups of 20 to 50 cetaceans or even hundreds when a large group of mammals is involved.
Additionally, shark-infested waters make it dangerous to actively refloat whales stranded on the islands, according to The Guardian.
“Because of the risk of shark attack to both humans and whales, our trained team euthanized the surviving whales to prevent further suffering,” Dave Lundquist, the government’s marine technical adviser, told AFP.
Daren Grover, general manager of the Project Jonah rescue organization, said many of the whales were already dead when they washed ashore and the rest were sick, according to CNN.
The Chatham Islands are “a stranding hotspot, among the top three stranding locations in New Zealand,” says the Department of Conservation, according to The Guardian.
Euthanise stranded whales
Euthanasia of stranded large whales poses logistical, safety, pharmaceutical, advertising, and disposal challenges. Once a baleen whale runs aground, the gravitational effects that lead to respiratory and circulatory collapse leave little doubt about the final outcome, although it may take several days for death to occur. It can be reasonably argued that allowing a stranded whale to die naturally.
However, slow cardiovascular collapse, often combined with severe blistering of the skin, live animals feeding on carrion, hyperthermia, distress, or serious injury, generally motivate humane efforts to end the animal’s suffering. The size of the animals and environmental conditions can pose safety concerns for stranded personnel.
Etorphine has been used as an intramuscular euthanasia agent for large stranded whales in the UK, but concerns for the safety of personnel in an already dangerous stranding environment and controlled drug restrictions have inhibited the widespread adoption of ultrapotent opioids for this application.
In this case, the right whale was still alive, but it was too late to rescue it. While vets often wait for several high tides to see if the whale can be saved, the outlook is often bleak. Stranded whales or whales entangled beyond rescue can be killed by exploding grenades, explosives, high-calibre guns and drugs. However, methods of drug euthanasia of large whales are not sufficiently developed and should not be used.
It is the sheer size of these critters that makes helping them such a challenge for wildlife vets. In most cases, all a veterinarian can hope to do is provide a quick, painless, humane death. “Euthanasia of stranded large whales,” Harms writes in a recent issue of the Journal of Wildlife Diseases, “poses logistical, safety, pharmaceutical, delivery, public relations, and disposal challenges.”
Live stranding is a brutal business. Even a moderately sunny day causes the animal’s skin to erupt in massive blisters. When they break, they release litres of fluid and leave open sores. The animal cannot defend itself, so crabs and birds peck at the dying animal’s fat whenever they can. The soft, fleshy eyes of the whale, on a young humpback, about the size of a small grapefruit, are another favourite of scavengers. Worst of all, a stranded whale can languish like this for more than a week.
According to the American Veterinary Medical Association, euthanasia “should result in rapid loss of consciousness followed by cardiac or respiratory arrest and ultimate loss of brain function.” In most cases, it recommends that the sick animal be given a barbiturate such as sodium pentobarbital, which is also used in some parts of the world to carry out the death penalty on humans.
- What Is COP27, And Why Is It So Important?
- 5 Biggest Environmental Issues In India In 2022
- More Than 1,700 Environmental Activists Murdered In Past Decade