What brought more than 1,000 octopuses to nurse their eggs in Monterey Bay?

Explorers find thousands of small octopus clustered in brooding positions in an unexplored area of the Monterey Bay National Marine Sanctuary.


Scientists have discovered an octopus nursery of sorts in Monterey Bay.

More than 1,000 of the cephalopods were seen last week clustered in a previously unexplored, federally protected area off California’s coast, their bodies tucked upside down into nooks with their tentacles inverted and covering clusters of white eggs.

Researchers were awed by the sight of the large, rocky landscape speckled with hundreds of the sea creatures, which looked like bright dots glowing in the dark ocean.


Scientists and educators were among those who observed images from remotely operated vehicles aboard the Ocean Exploration Trust’s Nautilus, a 211-foot vessel that has been charting previously unseen marine life and capturing it on a 24-hour livestream since June.

“To find something like this in our sanctuary, let alone in the West Coast, is pretty mind blowing,” said Chad King, a marine biologist with the Monterey Bay National Marine Sanctuary and lead scientist for the expedition.

The researchers said that this type of gathering of deep-sea octopuses has been reported only once before, when a smaller group of about 100 were brooding eggs in hydrothermal water off Costa Rica.

During the hour that the Nautilus research team observed the octopuses off the California coast, King said, the scientists saw no end to creatures lined up in the cracks of the rocks, from which an unknown shimmering fluid was seeping. There are more questions than answers as they left the area.

The clear pattern of where the octopuses were located indicates a relationship between the fluid seeping out of the rocks and where they chose to lay their eggs.

“What we don’t know is why,” he said. “Some people may assume it’s because [the fluid] is warm or there’s higher oxygen levels or maybe it cleans their eggs.”

The researchers were unable to take the water’s temperature or detect what other chemicals might be flowing out of the rocks, King said, so the reason for the choice of nursing ground will remain a mystery until more research is done.

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