Beached

And then, sadness turned to shock and bafflement when just three days later a further 250 whales beached on nearby Pitt Island and the same scenes played out a second time. Again, all whales died or were euthanised in an eerie replay of the first stranding. To many it seemed like the grisly intro to an end of the world sci-fi flick.

While whale strandings will always be disheartening, we are beginning to have a greater understanding of why they happen. Part of the reason the Chatham Islands seems to feature so heavily in the stranding narrative, says Daren Grover, General Manager of Project Jonah New Zealand, is its geographic location.

While we may feel helpless in the face of whale strandings, there is something that each and everyone of us can do.

“The Chathams have very deep, cold currents running up into shallow, warmer waters that sit on the Chatham Rise and this tends to turbo charge the food chain,” he says. “Phytoplankton thrive in these environments and as they are central to several food webs they will naturally attract larger predators, like whales. So there will be a lot of activity there.”

Project Jonah rose out of the ‘save the whales’ movement in the 1970s, and since then has grown into a champion for the welfare of whales, dolphins and seals, advocating for environmental measures to protect these animals and to educate people about them. They also work alongside the Department of Conservation to assist with strandings, which means for them the Chatham Islands beachings are particularly challenging.

“Whales and dolphins have been stranding throughout recorded history - long before manmade sonar was invented.”

“The remoteness of the Chathams means a response is very difficult,” says Daren, “because you can’t just rustle up a few hundred volunteers when there are only about 700 people there. And of course, once you have a few dead whales in the water there is also going to be a shark presence very, very quickly, so we can’t risk putting people into the water around the whales. As a result, live stranded whales are often euthanised.”

As for why strandings occur, Daren says there is no single cause. “There are many reasons for strandings. Whales have very tight social bonds, meaning when one is sick or old they will come ashore to save energy. The social bonds draw the other members of the pod to shore, accompanying that individual because the ‘safety in numbers’ bond is triggered. Normally they would leave once the sick individual has passed away, but often they are caught out by unfamiliar terrain and tides and end up stranded.

This happened just recently in November 2023 when a pod of whales entered a cove on Kawau Island and one member stranded and passed away before the rest of the pod returned to deeper water.”

There can also be manmade factors at play. “The primary sense for whales and dolphins is hearing, and sound travels four times more effectively through water than air. Evidence from the United States says military sonar can damage the hearing of these mammals, and very loud sounds can also trigger a flee response, meaning they may surface too quickly and just like in humans be effected by ‘the bends’ (nitrogen bubbles forming in their blood) which can lead to injury.

It could also be that feeding and rest cycles are interrupted by these noises, but at this stage we just don’t know for sure.”

“What we do know is that whales and dolphins have been stranding throughout recorded history - long before manmade sonar was invented - so it’s likely that strandings are the result of a variety of causes; disease, illness, injury, a near miss from another predator, and then you have natural factors like being caught out by unfamiliar terrain. Very strong weather fronts can also push whales and dolphins into shallows or unfamiliar coastal waters, and some people believe undersea earthquakes could also be to blame as these would cause extremely loud underwater sound waves.”

While we may feel helpless in the face of whale strandings, there is something that each and everyone of us can do. The Project Jonah website has some great educational resources and as the eyes of the Project you can help by reporting any whales, dolphins or seals that you think may be in trouble directly to them or to the Department of Conservation. We might not be able to save all of the whales, but together we might just save some.