And yet, Blue Planet succeeded amply. It took us to fantastical worlds, from belching hydrothermal vents to a whale fall—the decaying carcass of a sunken whale. It avoided the usual menagerie of clownfish, penguins, and sharks in favor of oddities like the improbably dentured fangtooth, slimy hagfish, and Phronima, a parasite that inspired H. R. Giger’s chest-bursting alien. It even showed us species that were new to science, like the Dumbo octopus, so named for the earlike flaps that protrude from its head.
In some ways, the sequel series treads the same ground as the 2001 original, featuring similar locations (the original ended on a brine lake), similar creatures, and even the same structure, sinking deeper and deeper as the minutes tick by. But it also considerably ups the ante on its predecessor. It features a love story between two shrimp. This species of shrimp, as larvae, will waft into a Venus’s flower basket sponge, and grow up trapped within its crystalline walls. It shows how abundant life can be in belching underwater volcanoes and the cold depths of Antarctica. It reveals bubbles of methane violently erupting from the ocean floor in front of a submersible’s headlights, like rockets launching in front of an angry sun.
I talked to the producer Orla Doherty about rising—or perhaps, sinking—to the challenge. This interview has been edited and condensed for the sake of clarity.
Ed Yong: Did you feel a sense of responsibility to live up to the legacy of that original deep ocean episode?
Orla Doherty: That episode blew everyone’s brains, my own included. When they told me they’d like me to make the deep episode, I kind of gulped. The largest habitat on Earth. The most unknown habitat on Earth. The hardest to get into. Oh, thanks a bunch, everyone. I remember being in that original planning meeting and thinking: Wow, I am literally out of my depth. My worst fear was that we’d make a poor man’s imitation of the original episode.
We did an awful lot of research: I have about 250 deep-ocean scientists in my inbox on a regular basis. In my first few weeks, Alex Rogers at Oxford told me about the shrimp and the sponge. I thought: Oh my god, it’s a love story in the deep ocean. We cannot leave the Galapagos without finding the Venus’s [flower] basket sponge.
Yong: When you plan a show like this, do you head out with a checklist of things to film, or do you venture into specific places and cross your fingers?
Doherty: You don’t just take out your submarine and go out exploring. Our first shoot, we tried to film shoals of lanternfish, spawning in biblical numbers. But that’s in the open ocean, where they can escape in three dimensions—and that’s what they did. It was a very informative disaster. It made me think that we should strike a balance between going for these animals that move around, and going to very fixed points where we know animals congregate.