Researchers have discovered a rare, deep-sea octopus nursery off the western shore of Costa Rica, complete with mother octopuses brooding their eggs and newly emerged hatchlings, according to a statement from the Schmidt Ocean Institute. The team also confirmed that a previously known gathering site of deep-sea octopuses is also an active nursery.
Before these two new finds, scientists knew of only one deep-sea octopus nursery, located on a seamount off California’s coast.
The new research “proves there is still so much to learn about our ocean,” Schmidt Ocean Institute’s executive director, Jyotika Virmani says in the statement. “The deep sea off Costa Rica rides the edge of human imagination, with spectacular footage collected by ROV SuBastian of tripod fish, octopus hatchlings and coral gardens.”
Last month, 18 international researchers boarded Schmidt Ocean Institute’s research vessel Falkor (too) for a three-week expedition to explore minimally studied underwater mountains in the Pacific Ocean. Their primary focus was the Dorado Outcrop, a football field-sized area near a hydrothermal vent that releases fluids at about 54 degrees Fahrenheit.
In 2013, researchers had witnessed female octopuses gathering there to brood their eggs, but they hadn’t spotted any developing embryos. As a result, the team suggested the location could be too hot to support octopus growth. Normally, octopuses are solitary creatures that stick to colder, deep-sea waters.
But using a remotely operated underwater vehicle, the team last month captured camera footage of octopus hatchlings emerging from their eggs at the Dorado Outcrop, as well as at the other, previously unexplored site.
“The mission control room erupted in squeals of amazement—people pointing their fingers at the screens excitedly, clapping, hugging—when we witnessed live baby octopuses on the seafloor,” expedition co-leader Beth Orcutt, vice president for research at the nonprofit research institute Bigelow Laboratory for Ocean Sciences, tells Scientific American’s Ashley Balzer Vigil.
Deep-sea octopus brooding is a long process—in one case, an octopus brooded its eggs for more than four years. During this time, octopus mothers must keep the eggs clean and protect them from predators. They eat very little—or perhaps nothing at all—and eventually waste away or self-destruct after laying just one clutch.
Researchers aren’t sure why these animals are drawn to the hydrothermal vents, but they say it’s possible the warm fluids help speed up their eggs’ development.
The brooding octopuses may be a new species of Muusoctopus, a genus of small- to medium-sized octopuses that do not have ink sacs. Scientists at the University of Costa Rica are now examining specimens collected from the expedition, writes Alison Snyder for Axios. The expedition explored five never-before-seen seamounts, which contained hundreds of animals, many of which may also be new species, per the statement.
“What we found is a very rare event world-wide, the nursing octopus, but we also encountered many organisms of which there are few records from anywhere in the planet,” expedition co-leader Jorge Cortés-Núñez, a marine biologist of the University of Costa Rica, tells Axios. “Creatures much larger than I have read about and many very strange and different from anything I have seen.”
Deep-sea critters face a myriad of threats from humans, including climate change, which has led to warming waters and reduced oxygen levels, per Scientific American. Currently, the seamounts studied on the expedition do not have legal protection, and researchers are working to determine whether they should receive marine protected status.
“If even a few organisms are unable to thrive in alternate conditions, there could be wide-reaching consequences to ecosystem dynamics,” Anne Hartwell, an oceanographer at the University of New Hampshire who was not involved in the expedition, tells Scientific American. “There is a sea of knowledge to be learned about deep-sea biodiversity and ecology.”