A brutal and "elaborate" attack on a whale by about 50 orcas has been documented on camera off WA's south coast.

Key points: A tour group has witnessed a large-scale orca hunt off the coast of Western Australia that ended in the gory demise of a beaked whale

A tour group has witnessed a large-scale orca hunt off the coast of Western Australia that ended in the gory demise of a beaked whale The kill was documented by marine biologist Brodee Elsdon, who said the hunt may have been a training exercise for orca calves

The kill was documented by marine biologist Brodee Elsdon, who said the hunt may have been a training exercise for orca calves The scene unfolded in a renowned marine hotspot, the depths of which are currently being plumbed by a leading research vessel

Marine biologist and photographer Brodee Elsdon witnessed the hunt from start to finish at the Bremer Canyon, a globally renowned marine hotspot east of Albany.

Ms Elsdon said the hunting skill of the orca was on full display, with at least three pods working in concert for at least an hour to seal the beaked whale's fate.

"This was the most graphic and elaborate kill of the season," she said.

"We had finally witnessed the hunt from the chase right through to the predation."

Whale watchers in Bremer Bay witnessed the most "graphic" and "elaborate" kill of the season. ( Supplied: Brodee Eldson )

Surge of death

The sight of the whale's demise left tourists and crew on board the whale-watching vessel in shock.

The tour arrived at the canyon about 70km off the south coast, under stormy skies, with heavy rain starting to fall.

"All of a sudden all the animals starting surging," Ms Elsdon said.

"It means they're picking up speed and it usually happens when they've honed in on their prey."

Orca will call out to other pods in the area to work together to take down an animal.

"In this case all the pods surged in one direction," Ms Elsdon said.

"We were probably going about 15 knots trying to keep up with the orca."

Marine Biologist Brodee Elsdon said the hunt was a "training" session for the young orcas. ( Supplied: Steve Reynolds )

First blood

But suddenly, Ms Elsdon said, the scene went eerily quiet.

"It all came to a halt … no orcas, dead silence, just rain falling," she said.

Minutes later, however, the whales surged to the surface, forcing the beaked whale, estimated to have been 4-6 metres long, up with them.

"We probably had about 50 orcas around the boat," Ms Elsdon said.

"They are the apex predator, they can take down an animal within a few minutes."

But this attack lasted much longer than normal — possibly, Ms Elsdon said, because it was a training exercise for the many calves involved in the hunt.

"Some of the calves were leaping over the beaked whale and trying to push it down, while the females pushed up from below," she said.

"It's always the females which teach the juveniles.

"This went for more than an hour right beside us."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 24 seconds 24 s Killer whales communicate with Australian accents ( Sean Murphy )

A kill fit for a queen

The final blow was landed by the huntress of the matriarchal pod.

"The last time they surfaced it, there was a huge blood bubble," she said.

"The huntress came in from the side and took the animal out.

"The females then came in and shared the meat out to the rest of the pod."

The RV Falkor and her crew of scientists and marine engineers will spend a month exploring the Bremer Bay canyon. ( ABC Great Southern: Ellie Honeybone )

The canyon has garnered international interest including the attention of one of the world's leading scientific vessels, the RV Falkor.

The research vessel, owned by the Schmidt Ocean Institute, founded by former Google chief executive Eric Schmidt and his wife, has spent the past few weeks using underwater imaging to investigate the canyon floor.