Apologies for the headline, but you cannot approach the Octopus Garden without the Beatles song playing in your head. This garden is two miles deep at Davidson Seamount, an area in the Pacific Ocean off the coast of California. It's a popular nesting ground for the pearl octopus (Muusoctopus robustus), and may contain as many as 20,000 octopuses and their eggs. The Octopus Garden is the largest octopus nesting area ever discovered. It was first noticed in 2018, but with new technology, the Monterey Bay Aquarium Research Institute (MBARI) has gotten an up close look.
Why do octopuses come here to nest? The garden is among the remains of an extinct volcano, where there are thermal vents that warm the water. At that depth, you would expect water temperatures to hover around 35°F (1.6°C), but those thermal vents bring the surrounding water up to 51°F (11°C). The warmer water causes octopus eggs to mature much faster, which shockingly takes years anyway. MBARI has much more on these octopuses at their website. -via Metafilter