Earlier this month, a three-crew submarine dove to Cook seamount, a 4000m-tall extinct volcano off the coast of Hawaii that had never been visited by humans. They discovered dazzling geologic features and a rich array of marine life — including a rare and adorably dopey octopus, and some beautiful purple corals that may be a new species. Gif by Gizmodo via Conservation International/YouTube
Seamounts, towering volcanoes submerged thousands of metres below the surface, are considered undersea jungles, their nutrient-rich waters supporting a panoply of fish and marine invertebrates. They're also some of the most poorly-explored habitats on the planet — of the estimated 10,000 peppering our oceans, humans have only visited a few dozen. That's why, on September 6, Conservation International led an expedition to Cook, whose summit lies 900m down in total darkness.
The trip did not disappoint.
Among the odd creatures found cooling their heels on the slopes of Cook's dead caldera were two Dumbo octopuses, rare colour-changing creatures that look like a bit like those iconic space whales of hippie lore. In the video above, one of these friendly aliens appears to be shedding its skin. The team also spotted the Pacific sleeper shark, a reclusive underwater giant that can grow up to 6m in length, and the purple chimaera, a "living fossil" that's been haunting the deep ocean for hundreds of millions of years.
Finally, the crew managed to pluck a sample of a vibrant, deep sea coral that might be a new species.
A brittle star clings to a purple coral, one of two species discovered on Cook seamount that may be new to science. Image: Conservation International/photo by Kevin Connor
Acanthagorgia coral sample collected from Cook seamount on September 6, 2016, as seen under a microscope. It may represent a new species. Image: Conservation International/photo by Kevin Connor
Expeditions like this are a reminder that just because the deep ocean is far removed from our everyday experience, doesn't mean it's a lifeless wasteland. In fact, the more we learn about the strange biology of the abyssal world, the clearer it becomes that this is a unique part of our biosphere, as deserving of protection as any other.