IN July, Scotland witnessed one of the largest mass whale stranding events in its history.
Traigh Mhor beach on Lewis suddenly became the setting of a tragedy as 55 pilot whales washed ashore and struggled for life in the surf.
Attempts to refloat them by volunteers were all but fruitless - only one whale was successfully refloated while the rest either drowned or were euthanised on the beach.
“There was a big swell,” said Dr Andrew Brownlow, a senior lecturer in veterinary epidemiology at the University of Glasgow and director of the Scottish Marine Animal Stranding Scheme (Smass).
“They came onto the beach as a group, weren’t able to keep themselves upright in the waves, aspirated a lot of seawater and sand, and they drowned.
“By the time we got to them, they had only been there for a few hours yet around 70% of them had already died”.
Mass strandings of these whales are by no means unique. In 2022, nearly 200 pilot whales died after stranding on a beach in Tasmania.
Their name itself betrays an occasionally fatal behavioural habit - the matriarchs of the group "pilot" the pod and are meticulously followed wherever they go, even onto the shore.
Indeed, this behaviour is a strong contender as to why these whales became stranded on Lewis.
“Two of these animals were in the process of giving birth,” said Brownlow.
“We know from observation of pilot whales that when females are giving birth the rest of the pod will corral around them to try and protect the newborn calf from any threats.
“But that behaviour leads to risk, as if one of them gets into trouble, the rest are likely to follow.”
Yet while one female getting into difficulty during birth may explain what caused the whales to strand, it doesn’t explain why they were in they were just off the shores of Lewis in the first place.
“To understand that, we have to ask whether they were pushed or pulled into the area,” said Brownlow.
The animals could easily have been led into the shallows while following their favourite prey of squid.
Equally, excessive industrial noise underwater or being chased by orcas could also account for their risky positioning.
It is mysteries such as these that Smass attempts to solve to help prevent future mass strandings and protect the cetaceans, sharks, seals and even turtles that call our waters home.
For more than 30 years, scientists in Scotland have gathered the carcasses of stranded marine animals in order to learn more about their lives and deaths.
However, stranded sea creatures – particularly whales – have long been regarded as a valuable resource.
Legislation dating back to at least 1324 gives the monarch the rights to all cetaceans washed up in England and Wales which, in years past, were prized for their meat and oil.
In Scotland, the Crown only has the right to “large whales”, which were latterly defined as animals stretching more than 25 feet from the snout to the middle of the tail.
With devolution, the responsibility for dealing with so-called “Royal Fish” in the country fell to the Scottish Government, which now manages their extraction and disposal via the Marine Directorate.
The Smass initiative performs necropsies on around 80-100 carcasses a year out of more than 1000 reported cases of strandings.
Around half the strandings involve seals while the rest involve cetaceans, with a small number of sharks and turtles thrown in too.
But locating, transporting, dissecting and disposing of these animals is not without its challenges.
“With sperm whales, you’ve got about 24-36 hours before the internal temperature gets so hot it effectively cooks itself,” said Brownlow.
“If left for that long, everything gasses up and you’re left dealing with what’s essentially a very smelly bomb that needs to be disposed of safely.”
What that looks like depends on where the animal washes up.
A remote beach in Shetland might allow for the digging of a large hole nearby, where the carcass can be buried and more than likely go undisturbed. It could even be left for other animals to scavenge and provide vital nutrient recycling for the whole ecosystem.
But a carcass on a beach in East Lothian is more likely to be lifted onto a truck and taken to landfills (which Brownlow described as “not the nicest place to perform a necropsy”).
The dedicated team of staff and volunteers, as well as Scotland’s helpful land access laws and cooperation from local councils, mean more and more data can be gathered about the 23 species of marine animals which frequent our waters.
The pilot whale stranding is a case in point.
“We got more data and samples from this stranding than any other in our history,” said Brownlow.
“Speaking to colleagues from other parts of the world, I think we’ve got one of the best data sets for a pilot whale stranding ever gathered.”
The more scientists can learn about these animals, the better advice they can give towards helping governments to protect them.
For example, after the Royal Navy detonated three 1000-pound bombs off the coast of Garvie Island left over from a military exercise in 2011, scientists were able to conclude that the explosions caused a stranding which resulted in the deaths of 19 pilot whales.
Now, they dispose of unexploded underwater bombs in a manner that doesn’t spook or deafen pilot whales.
“I feel a great responsibility to do right by them and find out what happened,” said Brownlow of the whales stranded on Lewis. “If it turns out the stranding was down to the unfortunate circumstances of weather and decision-making that’s fine. I don’t have an agenda to peddle.
“But we do need to find out this information because these scenes are incredibly traumatic for anyone who witnesses them.
“I’ve done this for many, many years and I’m still surprised by my own emotional response.
“These are highly complex social animals and there’s this dichotomy at play when we see them, particularly up close.
“On the one hand, they feel like distant cousins with a similar mammalian history unlike, say, a fish. We feel a connection there.
“Yet they also exist in this completely different environment, literally seeing the world with different senses in a habitat we don’t understand fully.”
There is still so much we don’t know about the lives of the species which occasionally find themselves in difficulty on our shorelines.
Smass recently performed a necropsy on a True’s beaked whale found on Lewis – only the second time a carcass of that species has been recorded in Scotland.
So little is known about them that scientists still aren’t sure what they eat.
The full investigation into the stranding on Lewis is yet to be completed and it’s still unclear whether any human activity contributed to the tragedy.
But the work of Smass ensures that, with time, we will more about these creatures and be better equipped to help them.
