Davidson Seamount -- an extinct underwater volcano off the coast of California -- has been described as “an oasis of the deep.” It’s home to huge coral reefs -- some of them more than a century old. It hosts crabs, many species of deep-sea fish, and big fields of sponges. And scientists recently discovered something else: the largest congregation of octopuses seen anywhere in the world -- more than a thousand of them. They nicknamed the spot the Octopus Garden.
The seamount is the largest undersea volcano in American waters. It’s 26 miles long and 7500 feet tall. It’s in Monterey Bay National Marine Sanctuary, where its profusion of life is protected.
In October of 2018, scientists were exploring the seamount with underwater robots. The cameras revealed more than a thousand octopuses, in several large groups. That’s hundreds more than have been seen together anywhere else.
Almost all of the octopuses were “brooding” females. They were nestled upside-down in the rocks, with their arms spread out to protect themselves and their eggs. The eggs were cemented to the rocks so they wouldn’t drift away.
The researchers also discovered a “fountain” of hot water shooting from the ocean floor several miles away. The water flowed over the octopuses, with temperatures up to 15 degrees higher than the surrounding waters. The warmer water could be one reason the octopuses congregated there -- in an Octopus Garden off the coast of California.