The first episode of Asia, David Attenborough's latest nature documentary, invited viewers into the deep blue sea.

The episode, which was suitably subtitled 'Beneath The Waves,' introduced viewers to plenty of sea-dwellers, including baby sperm whales, dusky sharks, firefly squids, and Moorish idols -- who you may well recognise as the fish from Finding Nemo.

But the most memorable segment of the episode took us to Tyuleniy Island in far eastern Russia. Here, we were introduced to northern fur seals -- but one moment in particular sparked opinion online.

What, how, and why?

In the show, Attenborough explained how the fur seals would dive into the ocean to fish for their food, which, unfortunately, landed them face-to-face with orcas. "These orca are specialists, ramming and tail slapping to stop their prey," Attenborough said. "And when their victim has been disabled, they drown it."

Over on X, viewers all said the same thing about the appearance of orcas. "It wouldn't be a David Attenborough series without Orca hunting down some poor creatures," one wrote. While another shared a Mr. Blobby GIF in reference to "Orcas gatecrashing a David Attenborough programme."

"And here we go," a third quipped. "Another episode of 'All orcas are b*****ds.'" Furthermore, a fourth shared a Jim Carrey GIF in reference to orcas coming to "wreck the day."

But orcas aside, the violence didn't end there for the fur seals. An earlier, grisly moment in the segment detailed how the young pups in the overcrowded breach often got caught in the crossfire as adult male seals fought with each other. This led to some being severely injured, or crushed to death.

What else happened during David Attenborough's Asia?

Other notable creatures from the episode include the sea bunny sea slug, which evades becoming prey by eating sponges toxic to their predators, and the mudskipper: a tiny little fish that's able to shift mud 300 times its size.

Viewers learn that despite being a fish, the mudskipper usually remains on dry land. As long as it remains wet, it is able to absorb oxygen from the air. Joints in their fins help them to walk, and they can even climb trees. With this kind of agility, it should come as no surprise that the male skippers have to engage in fierce duels with fellow males if they want a mate.

Read More: David Attenborough

During the last segment of the episode, viewers were also shown the challenges involved with filming the Indonesian throughflow. As revealed on the show, a floating camera rig was used to capture the swirling, deadly whirlpools.