The blue whale: large in life, even larger in death

MY FIVE-year-old is in a phase where he is very curious about the relative sizes of things.

"How big is a blue whale?" (It is as big as 33 African elephants.)

"Is it bigger than a dinosaur?" (Yes.)

"Is it bigger than a megalodon?" (Yes.)

"Is it bigger than the universe?" (No)

The fact is, I have learned that the blue whale is the largest animal to have ever lived on Earth.

But somehow, I keep forgetting and each time I relearn this fact it amazes me just how big such a creature can be.

Yet even the biggest creature that ever lived can fall prey to the apex predator of the sea.

Scientists reported, for the first-time, evidence of a pod of orcas, or killer whales, not only attacking but killing and eating an adult blue whale off the coast of Western Australia.

The video shared was above the surface and if it was not clearly spelled out, one might not entirely understand why the footage was marked for "graphic images".

Without any sound except the gentle lap of waves crashing and breaking on the surface and against the gliding black-white bodies tangled with the dark grey blue, it is difficult to tell that a violent battle and a mammoth death was occurring.

Occasionally, the water would turn dark crimson, but the evidence of injury quickly ebbed away.

Orcas are not called wolves of the sea without reason.

Their intelligence and cooperation during hunts is unnerving, and their concerted method of predation may surpass the best of land hunters. (Sidenote: Wolves only have an estimated 14% successful kills, cheetahs 50% and African wild dogs top the list with 85% successful kills).

There is a story in Cherry-Garard’s memoir of his journey in Antarctica that illustrates the level of forethought and determination these marine hunters have, and it is immortalised in a beautiful sketch of the Polar photographer Herbert Ponting – barely averting his untimely demise at the edge of the ice.

The expedition party had brought a number of animals for their treks and of these were sled dogs, some of which were tethered on the ice.

The author recounted how he first saw the nostrils of one orca open within two yards of him.

The orca’s gush of breath reached him along with eight loud blows.

Soon after, the orcas disappeared under water only to rise again with a deafening crash from below two feet of ice, breaking it into floes.

The men fled and miraculously all survived.

One can only imagine the trauma of being marked as a target by these brilliant hunters.

The author reflected, "As I reached security and looked back, a huge black and tawny head was pushed out of the water at the spot, and rested on the ice, looking round with its little pig-like eyes to see what had become of me.

"The brute opened his jaws wide, and I saw the terrible teeth which I had so narrowly escaped."

Indeed, few prey of the orcas can be so fortunate to escape with such a memory—and now we know for certain even a giant of the sea was not one of them.

At the end of the short video I mused, "Wow, I guess the body will float for a while."

My eight-year old quickly corrected me, "No, whales will sink mom. It’s called a ‘whale fall’."

This fact is new to me. I had never thought about what would happen to the remains of so large an animal at sea.

The fact is the dead whale would not only provide food for the orcas that so deftly bested it.

Many other fish and birds will get their fill as well.

Eventually what is left of the whale would continue to sink several kilometres down to the depths of the ocean until it reached the seabed – thus aptly called "whale fall".

Often, the whale lands on the seafloor so deep that there is scarce food to support life.

The few specialized sea creatures that do survive here can live on the remains of a single whale for up to two years.

Invertebrates such as sea snails, worms and shrimp eat off scraps to reveal clean bones as well as organic matter produced from microbes decomposing the carcass.

Communities of microbes and other deep sea floor creatures flock to the fallen whale, building new ecosystems, producing generations of offspring, on an otherwise barren site.

They say the bigger they are, the harder they fall.

In the case of a whale, their colossal fall in death explodes into a brilliant burst of macroscopic and microscopic life.

Of course, the image of such a large animal being attacked and succumbing to a number of smaller animals is not a pleasant thing to observe.

But it is interesting to reflect that while the orca does not have a natural predator in the sea, it does have one from land – humans.

Though much smaller than orcas and whales, human whaling activities have brought several of these marine species to near extinction.

Experts believe the grisly sight of a blue whale being eaten by orcas may actually be a sign that the whale population is becoming large enough to become fair game for their natural predators.

A sign of healthy restoration.

So while it is difficult to watch the death of a creature however small, let alone a gentle giant of the ocean - this is actually a happy ending.

Such a death further reassures us that when things are consumed based on need as is the way in nature, nothing goes to waste.

The end of one life becomes the beginning of many others.