Researchers use underwater technology in Bay Area to unlock mysteries of rare octopus garden

MONTEREY, Calif. -- The images are stunning.

Thousands of octopus moms are protecting their newly laid eggs on the ocean floor of the Monterey Bay National Marine Sanctuary.

And the underwater photography is helping to unravel a mystery of this real-life octopus garden, one of the few known nesting grounds of its kind in the world. It's the work of a research group that includes San Jose State University/Moss Landing Marine Laboratory and the Monterey Bay Aquarium Research Institute, also known as MBARI.

"It's almost like we opened a door and stepped into their living room. They're right there," says MBARI senior scientist Jim Barry, Ph.D.

Barry showed off the type of submersible vehicles -- used to monitor the site since it was first discovered in 2018 -- near an extinct sea volcano about 80 miles off the coast of Monterey. And since that time, researchers have also turned to increasingly sophisticated instruments to learn more.

"One is that we've had advances in technology and imaging for deep sea systems, you know. We're two miles under the surface, cold, dark, freezing high pressure. And yet, we're able to run these cameras and get great shots of these octopuses sitting there," Barry said.

And since the discovery, San Jose State Assistant Professor Amanda Kahn and her colleagues have worked to understand why the Octopuses migrate to the area to mate and eventually give birth to their young.

She says one clue was the water temperature.

"We saw that the water was shimmering and wavering in a way, kind of like you would see heat rising off the asphalt on a hot day. And that made us think that maybe there was something about the water conditions there," Professor Kahn said.

Using sophisticated thermometers, they confirmed their hunch. Water in the crevices was indeed, warmer. Part of an environment that allows the octopus eggs to incubate and hatch more quickly, and likely avoid predators as they grow.

Professor Kahn, who was on the research vessel that discovered the nesting area believes the newly published insites will highlight the critical role of preserving the marine sanctuary.

"You know, for a species that reproduces all in one area, you can have the really strong impact on that population by protecting that hotspot, right? That patch is going to help that whole species. And so yeah, it's very important that if we find these areas where octopuses are breeding, that those are vital, important areas for those species," she said.

Jim Barry adds that it could also provide important lessons for human behavior.

"We want to know more about what sort of resources we have on the seabed so that we can protect them before we just indiscriminately and inadvertently damage them either through fishing, mining, plastics, climate change, whatever it might be. Then we'll be able to make more informed decisions about how we should manage these resources.

Resources as exotic and stunning as a real-life octopus garden.

Other collaborators include NOAA 's Monterey Bay National Marine Sanctuary, The University of Alaska, Fairbanks, and the University of New Hampshire. The new study is being published in Science Advances.