Massive Deep-Sea Octopus Nursery Discovered Off California Coast
Scientists have identified the world’s largest known octopus breeding ground near the Davidson Seamount, estimating up to 20,000 pearl octopuses congregating there.
A collaborative team from MBARI, the Monterey Bay National Marine Sanctuary, NOAA, and the Ocean Exploration Trust documented an unprecedented concentration of Muusoctopus robustus on a small rise at the base of the extinct Davidson Seamount, roughly 130 kilometres southwest of Monterey. Using the ROV Doc Ricketts, scientists conducted 14 dives, observing adult males, females, developing eggs and hatchlings, but no intermediate-size individuals, indicating the site functions solely as a mating and nesting habitat.
Photomosaic mapping and the LASS imaging system revealed 5,718 octopuses in a 2.5-hectare core, within a broader 333-hectare elevation that could host over 20,000 animals. The presence of hydrothermal vents raises local water temperature to about 11 °C, a stark contrast to the surrounding 1.6 °C, shortening egg incubation from several years to under two. After spawning, the octopuses die, and their carcasses provide a substantial food source, boosting local biomass availability by roughly 72 %.
Why it matters
The find reveals how deep-sea thermal vents shape marine life cycles and could inform future biodiversity and climate studies.
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