Clash of two titans: Witnessing orcas hunt the largest animal on earth

"We started out the day just like any other day" recalls Adam Ernster. "There was so much to see. Pods of dolphins 100 strong, great big sea lion colonies, the largest fish in the world, and the largest animal in the world, the blue whale."

Wildlife cinematographer Adam Ernster recalls the day he witnesses one of the rarest predator-prey encounters ever documented: a pod of killer whales attempting to hunt a fully grown blue whale in the Gulf of California.

The Pacific coast of Mexico is one of the most biodiverse marine environments on the planet, sometimes known as the aquarium of the world, it plays host to many of the world's greatest wildlife spectacles. "The biodiversity here is unmatched," says Adam. "There is no telling what you will see on any given day."

"After searching for hours, we came across a group of three blue whales. The conditions were perfect" says Adam. "Blue whales are endangered, and this is about as far north as they would head in the Gulf of California, so seeing them was a really special treat. By the time we had spotted the blue whales, we already thought we'd had an extraordinary day."

Then everything changes.

As the team prepares to move on, signs of another encounter begin appearing on the horizon. "I just started seeing these blows everywhere," Adam recalls. "This only meant one thing. A huge group of about 20, Eastern Tropical Pacific (ETP) killer whales."

"The killer whales totally surrounded our boat. Many individuals had come together. Some of the younger animals checked out the boat, but it seemed like the rest of the pod was on a mission."

That mission soon becomes apparent and what happens next is beyond anything the crew expects to witness. Adam recalls "They were heading North to an area we had just come from... where the blue whales were."

"We never ever thought these orcas would go after a fully grown adult blue whale," says Adam. "The blue whales are just too big." Then, suddenly, the attack begins. "Lo and behold, a blue whale flies out of the water with four orcas on each flank. My mind was utterly blown. I couldn't believe my eyes."

What follows is an hours-long battle between the ocean's largest animal and one of its most formidable predators. "The scale of it was extraordinary," Adam says. "The blue whale was immense, but the orcas were working as a coordinated team. It felt like watching a battle between giants. At times it was a bit gruelling to see what this whale was going through, with teeth marks on its cheek and on its back. Surprisingly, for the most part, it looked unharmed."

Adam spends over 200 days a year at sea and has spent nearly a decade observing marine wildlife. The event is unlike anything he has witnessed before. "I was in complete and utter shock watching this group of killer whales attempt to hunt this blue whale," he says. "I have never seen anything like this. Not even close."

Filming presents its own challenges. For hours the crew follows the giants and tries to keep up with rapidly moving animals spread across a vast area of ocean. "In the moment, I just tried to stay present and appreciate what was unfolding before me," Adam says. "I tried to capture this rare event to the best of my abilities. I didn't put my camera down for four hours straight."

For marine mammal scientist Bob Pitman, encounters like this are becoming more expected. "Nothing killer whales do surprises me anymore. They are very large and very intelligent; they live and hunt in family groups for decades - they are the ultimate marine predator, and because they hunt in packs, like wolves, nothing is too big for them to take on."

Blue whales were once far more abundant than they are today. Across much of the twentieth century, commercial whaling reduced populations to a fraction of their former numbers. For Bob, this encounter may be more than just a remarkable wildlife spectacle. It may offer a glimpse into how ocean ecosystems functioned before industrial whaling dramatically reduced great whale populations worldwide. "During the last century, killer whales attacking a blue whale was almost unheard of, but now that blue whale populations are on the road to recovery in some areas, due to the cessation of whaling, perhaps killer whales are learning once again how to take on the world's biggest prey."

As daylight fades for Adam, the ultimate outcome remains uncertain. "Ultimately, we will never know what happened to the blue whale," says Adam. "It didn't seem like it was tiring at all. It was coming up every 45 seconds. It didn't seem like it was ready to give up its life."

The memory remains vivid. "When I look back at photos and videos from this day, I still can't believe it's real. I think about this encounter every day of my life. To me, this is the most powerful spectacle the planet has to offer. You have the ocean's apex predators and the largest animal to have ever existed going toe-to-toe, or tail-to-tail. "

But beyond the drama, Adam hopes viewers take away something larger. "I want people to understand that the oceans hold so much wonder. They are so complex. Places like the Gulf of California hold so much biodiversity that is crucial for the survival of our planet. I hope when people see something as grand as killer whales hunting a blue whale, two titans battling it out on the high seas, they see something worth protecting. Something that deserves our attention, our curiosity and our respect."