Humans are generally good at whole-body manipulation, but robots struggle with such tasks. To the robot, each spot where the box could touch any point on the carrier’s fingers, arms, and torso represents a contact event that it must reason about. With billions of potential contact events, planning for this task quickly becomes intractable.

Now MIT researchers found a way to simplify this process, known as contact-rich manipulation planning. They use an AI technique called smoothing, which summarizes many contact events into a smaller number of decisions, to enable even a simple algorithm to quickly identify an effective manipulation plan for the robot.

While still in its early days, this method could potentially enable factories to use smaller, mobile robots that can manipulate objects with their entire arms or bodies, rather than large robotic arms that can only grasp using fingertips. This may help reduce energy consumption and drive down costs. In addition, this technique could be useful in robots sent on exploration missions to Mars or other solar system bodies, since they could adapt to the environment quickly using only an onboard computer.

“Rather than thinking about this as a black-box system, if we can leverage the structure of these kinds of robotic systems using models, there is an opportunity to accelerate the whole procedure of trying to make these decisions and come up with contact-rich plans,” says H.J. Terry Suh, an electrical engineering and computer science (EECS) graduate student and co-lead author of a paper on this technique.

Joining Suh on the paper are co-lead author Tao Pang PhD ’23, a roboticist at Boston Dynamics AI Institute; Lujie Yang, an EECS graduate student; and senior author Russ Tedrake, the Toyota Professor of EECS, Aeronautics and Astronautics, and Mechanical Engineering, and a member of the Computer Science and Artificial Intelligence Laboratory (CSAIL). The research appears this week in IEEE Transactions on Robotics.

Learning about learning

Reinforcement learning is a machine-learning technique where an agent, like a robot, learns to complete a task through trial and error with a reward for getting closer to a goal. Researchers say this type of learning takes a black-box approach because the system must learn everything about the world through trial and error.

It has been used effectively for contact-rich manipulation planning, where the robot seeks to learn the best way to move an object in a specified manner.

But because there may be billions of potential contact points that a robot must reason about when determining how to use its fingers, hands, arms, and body to interact with an object, this trial-and-error approach requires a great deal of computation.

“Reinforcement learning may need to go through millions of years in simulation time to actually be able to learn a policy,” Suh adds.

On the other hand, if researchers specifically design a physics-based model using their knowledge of the system and the task they want the robot to accomplish, that model incorporates structure about this world that makes it more efficient.

Yet physics-based approaches aren’t as effective as reinforcement learning when it comes to contact-rich manipulation planning — Suh and Pang wondered why.

They conducted a detailed analysis and found that a technique known as smoothing enables reinforcement learning to perform so well.

Many of the decisions a robot could make when determining how to manipulate an object aren’t important in the grand scheme of things. For instance, each infinitesimal adjustment of one finger, whether or not it results in contact with the object, doesn’t matter very much. Smoothing averages away many of those unimportant, intermediate decisions, leaving a few important ones.

Reinforcement learning performs smoothing implicitly by trying many contact points and then computing a weighted average of the results. Drawing on this insight, the MIT researchers designed a simple model that performs a similar type of smoothing, enabling it to focus on core robot-object interactions and predict long-term behavior. They showed that this approach could be just as effective as reinforcement learning at generating complex plans.

“If you know a bit more about your problem, you can design more efficient algorithms,” Pang says.

A winning combination

Even though smoothing greatly simplifies the decisions, searching through the remaining decisions can still be a difficult problem. So, the researchers combined their model with an algorithm that can rapidly and efficiently search through all possible decisions the robot could make.

With this combination, the computation time was cut down to about a minute on a standard laptop.

They first tested their approach in simulations where robotic hands were given tasks like moving a pen to a desired configuration, opening a door, or picking up a plate. In each instance, their model-based approach achieved the same performance as reinforcement learning, but in a fraction of the time. They saw similar results when they tested their model in hardware on real robotic arms.

“The same ideas that enable whole-body manipulation also work for planning with dexterous, human-like hands. Previously, most researchers said that reinforcement learning was the only approach that scaled to dexterous hands, but Terry and Tao showed that by taking this key idea of (randomized) smoothing from reinforcement learning, they can make more traditional planning methods work extremely well, too,” Tedrake says.

However, the model they developed relies on a simpler approximation of the real world, so it cannot handle very dynamic motions, such as objects falling. While effective for slower manipulation tasks, their approach cannot create a plan that would enable a robot to toss a can into a trash bin, for instance. In the future, the researchers plan to enhance their technique so it could tackle these highly dynamic motions.

“If you study your models carefully and really understand the problem you are trying to solve, there are definitely some gains you can achieve. There are benefits to doing things that are beyond the black box,” Suh says.

This work is funded, in part, by Amazon, MIT Lincoln Laboratory, the National Science Foundation, and the Ocado Group.

Large spots are common features in the atmospheres of giant planets, the most famous being Jupiter’s Great Red Spot. On Neptune, a dark spot was first discovered by NASA’s Voyager 2 in 1989, before disappearing a few years later. “Since the first discovery of a dark spot, I’ve always wondered what these short-lived and elusive dark features are,” says Patrick Irwin, Professor at the University of Oxford in the UK and lead investigator of the study published today in Nature Astronomy.

Irwin and his team used data from ESO’s VLT to rule out the possibility that dark spots are caused by a ‘clearing’ in the clouds. The new observations indicate instead that dark spots are likely the result of air particles darkening in a layer below the main visible haze layer, as ices and hazes mix in Neptune’s atmosphere.

Coming to this conclusion was no easy feat because dark spots are not permanent features of Neptune’s atmosphere and astronomers had never before been able to study them in sufficient detail. The opportunity came after the NASA/ESA Hubble Space Telescope discovered several dark spots in Neptune’s atmosphere, including one in the planet’s northern hemisphere first noticed in 2018. Irwin and his team immediately got to work studying it from the ground — with an instrument that is ideally suited to these challenging observations.

Using the VLT’s Multi Unit Spectroscopic Explorer (MUSE), the researchers were able to split reflected sunlight from Neptune and its spot into its component colours, or wavelengths, and obtain a 3D spectrum [1]. This meant they could study the spot in more detail than was possible before. “I’m absolutely thrilled to have been able to not only make the first detection of a dark spot from the ground, but also record for the very first time a reflection spectrum of such a feature,” says Irwin.

Since different wavelengths probe different depths in Neptune’s atmosphere, having a spectrum enabled astronomers to better determine the height at which the dark spot sits in the planet’s atmosphere. The spectrum also provided information on the chemical composition of the different layers of the atmosphere, which gave the team clues as to why the spot appeared dark.

The observations also offered up a surprise result. “In the process we discovered a rare deep bright cloud type that had never been identified before, even from space,” says study co-author Michael Wong, a researcher at the University of California, Berkeley, USA. This rare cloud type appeared as a bright spot right beside the larger main dark spot, the VLT data showing that the new ‘deep bright cloud’ was at the same level in the atmosphere as the main dark spot. This means it is a completely new type of feature compared to the small ‘companion’ clouds of high-altitude methane ice that have been previously observed.

With the help of ESO’s VLT, it is now possible for astronomers to study features like these spots from Earth. “This is an astounding increase in humanity’s ability to observe the cosmos. At first, we could only detect these spots by sending a spacecraft there, like Voyager. Then we gained the ability to make them out remotely with Hubble. Finally, technology has advanced to enable this from the ground,” concludes Wong, before adding, jokingly: “This could put me out of work as a Hubble observer!“

Note

[1] MUSE is a 3D spectrograph that allows astronomers to observe the entirety of an astronomical object, like Neptune, in one go. At each pixel, the instrument measures the intensity of light as a function of its colour or wavelength. The resulting data form a 3D set in which each pixel of the image has a full spectrum of light. In total, MUSE measures over 3500 colours. The instrument is designed to take advantage of adaptive optics, which corrects for the turbulence in the Earth’s atmosphere, resulting in sharper images than otherwise possible. Without this combination of features, studying a Neptune dark spot from the ground would not have been possible.

“Patients should feel empowered to educate themselves about their medical conditions, but they should always discuss with a clinician, and resources on the Internet should not be consulted in isolation,” said corresponding author Danielle Bitterman, MD, of the Department of Radiation Oncology and the Artificial Intelligence in Medicine (AIM) Program of Mass General Brigham. “ChatGPT responses can sound a lot like a human and can be quite convincing. But, when it comes to clinical decision-making, there are so many subtleties for every patient’s unique situation. A right answer can be very nuanced, and not necessarily something ChatGPT or another large language model can provide.”

The emergence of artificial intelligence tools in health has been groundbreaking and has the potential to positively reshape the continuum of care. Mass General Brigham, as one of the nation’s top integrated academic health systems and largest innovation enterprises, is leading the way in conducting rigorous research on new and emerging technologies to inform the responsible incorporation of AI into care delivery, workforce support, and administrative processes.

Although medical decision-making can be influenced by many factors, Bitterman and colleagues chose to evaluate the extent to which ChatGPT’s recommendations aligned with the NCCN guidelines, which are used by physicians at institutions across the country. They focused on the three most common cancers (breast, prostate and lung cancer) and prompted ChatGPT to provide a treatment approach for each cancer based on the severity of the disease. In total, the researchers included 26 unique diagnosis descriptions and used four, slightly different prompts to ask ChatGPT to provide a treatment approach, generating a total of 104 prompts.

Nearly all responses (98 percent) included at least one treatment approach that agreed with NCCN guidelines. However, the researchers found that 34 percent of these responses also included one or more non-concordant recommendations, which were sometimes difficult to detect amidst otherwise sound guidance. A non-concordant treatment recommendation was defined as one that was only partially correct; for example, for a locally advanced breast cancer, a recommendation of surgery alone, without mention of another therapy modality. Notably, complete agreement in scoring only occurred in 62 percent of cases, underscoring both the complexity of the NCCN guidelines themselves and the extent to which ChatGPT’s output could be vague or difficult to interpret.

In 12.5 percent of cases, ChatGPT produced “hallucinations,” or a treatment recommendation entirely absent from NCCN guidelines. These included recommendations of novel therapies, or curative therapies for non-curative cancers. The authors emphasized that this form of misinformation can incorrectly set patients’ expectations about treatment and potentially impact the clinician-patient relationship.

Going forward, the researchers are exploring how well both patients and clinicians can distinguish between medical advice written by a clinician versus a large language model (LLM) like ChatGPT. They are also prompting ChatGPT with more detailed clinical cases to further evaluate its clinical knowledge.

The authors used GPT-3.5-turbo-0301, one of the largest models available at the time they conducted the study and the model class that is currently used in the open-access version of ChatGPT (a newer version, GPT-4, is only available with the paid subscription). They also used the 2021 NCCN guidelines, because GPT-3.5-turbo-0301 was developed using data up to September 2021. While results may vary if other LLMs and/or clinical guidelines are used, the researchers emphasize that many LLMs are similar in the way they are built and the limitations they possess.

“It is an open research question as to the extent LLMs provide consistent logical responses as oftentimes ‘hallucinations’ are observed,” said first author Shan Chen, MS, of the AIM Program. “Users are likely to seek answers from the LLMs to educate themselves on health-related topics — similarly to how Google searches have been used. At the same time, we need to raise awareness that LLMs are not the equivalent of trained medical professionals.”

Even as the field of human genomics forged ahead at an astonishing pace, the Y chromosome — one of the sex chromosomes — has long remained overlooked. It has been postulated that the human sex chromosomes once originated from a pair of structurally similar chromosomes, but subsequently one of the sex chromosomes, the ancestral Y chromosome, underwent significant degradation, losing 97%of its former complement of genes over many millions of years. This peculiar evolutionary trajectory has given rise to speculation that the human Y chromosomes might eventually disappear completely, albeit millions of years from now, and we already observe that some biological males do lose them in dividing cells as they age, with unclear health consequences.

In practical terms, the Y chromosome contains a large proportion of repetitive and heterochromatic (highly condensed, gene-poor and not transcribed to messenger RNA) sequences, making it exceptionally difficult to fully sequence. Using sequencing methods that can cover long, continuous sequences, the Telomere-to-Telomere (T2T) consortium has now published the first complete Y chromosome assembly from a single individual of European descent in “The complete sequence of a human Y chromosome” (Rhie et al. Nature). At the same time, a team led by Jackson Laboratory (JAX) Professor and The Robert Alvine Family Endowed Chair Charles Lee, Ph.D., FACMG, has assembled Y chromosomes from 43 unrelated males, with nearly half coming from African lineages in “Assembly of 43 human Y chromosomes reveals extensive complexity and variation” (Hallast et al., Nature). Taken together, these two papers provide intriguing insights into human Y chromosomes, reveal the highly variable nature of Y chromosomes across individuals, and provide an important foundation for future studies on how they may be contributing to certain disorders and diseases.

The need for long reads

Standard short-read genomic sequencing technologies require breaking genomic DNA into short (~250-base-long) fragments. These fragments are then reassembled into the full genome of more than 3 billion base pairs across 46 chromosomes in humans. The method is very accurate and works well for most, but not all, of the genome. Almost all “complete” human genome sequences, including the current reference genome sequence (known as GRCh38), are actually only about 90% complete, because it is difficult to assemble the highly repetitive and other complex sections accurately. GRCh38 falls particularly short for the Y chromosome, as it barely assembles half of that chromosome.

As a result, while the much larger and gene-rich other sex chromosome — the X chromosome — has been extensively studied, the Y chromosome has been often overlooked outside of male-based fertility studies. In a significant step forward for the genomics field, scientists from JAX, including first author and JAX Associate Research Scientist, Pille Hallast, Ph.D., with collaborators from Clemson University, Heinrich Heine University (Germany) and more, have now revealed a full picture of the Y chromosome’s key characteristics and differences between individuals for the first time. Of note is the striking variation in size and structure across the 43 Y chromosomes sequenced that covered 180,000 years of human evolution and range from 45.2 million to 84.9 million base pairs in length.

The inclusion of 43 different individuals representing diverse Y lineages allowed the researchers to redefine inter-chromosomal region boundaries and identify large-scale variations at an unprecedented resolution and clarity. The study also revealed an unexpected degree of structural variation across the Y chromosomes. For example, half of the euchromatin (gene-rich region) of the sequenced chromosomes carries large recurrent inversions — segments that contain the same nucleotide sequences but oriented in the opposite direction — at a rate much higher than anywhere else in the genome. The study further identified regions of the Y chromosome that demonstrate little single nucleotide variation but show high gene copy number variation for specific gene families. Other gene families tended to maintain their copy numbers, however, consistent with their roles in fertility and normal development.

Incredibly important research for overall health

“Having fully resolved Y chromosome sequences from multiple individuals is essential in order for us to begin to understand how this variation can affect function” says Hallast. “The degree of structural variation between individuals came as a big surprise to me, even though the nucleotide sequences within the Y chromosome genes are comparatively conserved. The variable gene copy numbers in certain gene families and extremely high inversion rates are almost certain to hold significant biological and evolutionary roles.”

The Y chromosome’s contributions to male health are poorly understood. Some unexpected indications of its importance to human health have recently come into focus in two new research studies that collectively implicate the Y chromosome in aggressive features of colorectal and bladder cancers in men. Indeed, one of the studies showed that tumors that had lost the Y chromosomes can more effectively evade T cell immunity, are infiltrated with higher numbers of dysfunctional CD8+ T cells, and are more responsive to anti-PD1 treatments compared to similar tumors retaining the Y chromosome.

“Research is emerging that shows proper Y chromosome gene function is incredibly important for the overall health of men,” says Lee, senior author on the paper. “Our study enables the inclusion of the full Y chromosome in all future studies when sequencing male genomes to understand health and disease.”

Fresh research from the University of Montana, international partners and NASA-affiliated scientists suggests that parks do indeed enhance bird diversity inside their borders. Large parks also support higher diversity of both birds and mammals in nearby unprotected areas.

The research was published Aug. 23 in Nature.

“We knew that protected areas can reduce logging — you can see that from satellite imagery — but you can’t see the animals in the forest from space,” said the study’s lead author Dr. Jedediah Brodie, the UM Craighead Chair of Conservation. “Our new analysis shows that parks benefit forest wildlife, too.”

Brodie also is a Universiti Malaysia Sarawak (Malaysia) research fellow. He said that some scientists have argued that conservation success inside some parks can come at the expense of neighbouring unprotected habitats — that parks displace extractive impacts like hunting, fishing and logging to other nearby areas.

But on the other hand, marine parks often report biodiversity “spillover,” meaning that species protected within park boundaries produce an abundance of eggs, larvae and adults that then disperse and increase the biodiversity in surrounding habitats.

“So the question is, ‘Do terrestrial land parks displace biodiversity losses or provide biodiversity spillover?'” Brodie said.

The new study recruited scientists from 10 countries to conduct a comprehensive analysis of bird and mammal diversity inside and outside of parks across Southeast Asia, one of the most biodiverse regions on Earth. The scientists compiled a massive database of bird and mammal observations across the region that demonstrated the protective features of national parks.

Brodie said the findings are especially timely for the United Nations, which recently announced ambitious biodiversity conservation targets that include significant expansions of global protected areas. The UN strategy is to conserve 30% of Earth’s lands and waters by 2030, the so-called “30 by 30 goal.”

“Massive expansions to global protected area coverage will be difficult and expensive, but our results show that it’s worth it,” Brodie said.

Indeed, the work provides clear justification to designate protected areas that are as large as possible, as larger parks had significantly stronger influence on mammal diversity in the surrounding landscape. Recent work in the region suggests that some wildlife species are persisting in small parks, but this apparently doesn’t scale up to such areas having landscape-scale “spillover” effects.

The time to move forward with protected area expansion is now, said co-author Professor Mohd-Azlan Jayasilan of the Universiti Malaysia Sarawak.

“If governments responsible for gazetting protected areas think that it is difficult to protect large areas now, it’s simply going to get more difficult with exasperating socio-political setbacks in the future,” Jayasilan said.

“Not all parks are equal,” said co-author Dr. Mairin Deith of the University of British Columbia, Canada. “Larger parks routinely had higher bird diversity. Considering the UN’s goal of increasing protected area to 30% of the world’s surface, these findings support the creation of fewer larger parks compared to many smaller ones, where it is possible to do so.”

At the same time, she said, there might be other invisible social forces researchers couldn’t see from their dataset that may be related to park size, such as differences in funding, enforcement and local buy-in to protections.

Hunting is a key concern for Southeast Asian wildlife conservation and a prime suspect for why diversity has often been assumed to decline outside of parks. Hunters are mobile, so hunting bans within park boundaries may only displace these activities to nearby unprotected areas and undermine their net benefit.

“To be honest, I was surprised that mammal diversity was higher outside large parks,” said co-author Dr. Matthew Luskin of the University of Queensland, Australia. “It’s common to see hunters inside and outside of parks in many countries. I expected that hunters’ selectively removing game animals would reduce diversity. However, it appears parks limit hunting so it does not drive complete extirpations in most cases.”

NASA’s Global Ecosystem Dynamics Investigation operates a near-infrared laser instrument on the International Space Station, providing vertical information on forest structure that the study used in its analysis. Co-author Scott Goetz of Northern Arizona University noted that “while satellite monitoring of forest cover is essential for tracking deforestation, the unique data provided by GEDI allows us to go beyond cover and get at the structural diversity and habitat heterogeneity of forests, which is important for biodiversity.”

Co-author James Ball of the University of Cambridge said, “Integrating NASA’s GEDI data into this analysis allowed us to control for 3D forest structure in a way that simply wasn’t possible a few years ago. This reassures us that the results hold across different forest types.”

In a new study published today in Science Advances, a team of researchers from MBARI, NOAA’s Monterey Bay National Marine Sanctuary, Moss Landing Marine Laboratories, the University of Alaska Fairbanks, the University of New Hampshire, and the Field Museum confirmed that deep-sea octopus migrate to the Octopus Garden to mate and nest. The Octopus Garden is one of a handful of known deep-sea octopus nurseries. At this nursery, warmth from deep-sea thermal springs accelerates the development of octopus eggs. Scientists believe the shorter brooding period increases a hatchling octopus’ odds for survival. The Octopus Garden is the largest known aggregation of octopus on the planet — researchers counted more than 6,000 octopus in a portion of the site and expect there may be 20,000 or more at this nursery.

“Thanks to MBARI’s advanced marine technology and our partnership with other local researchers, we were able to observe the Octopus Garden in tremendous detail, which helped us discover why so many deep-sea octopus gather there. These findings can help us understand and protect other unique deep-sea habitats from climate impacts and other threats,” said MBARI Senior Scientist Jim Barry, lead author of the new study.

The Octopus Garden is located 3,200 meters (10,500 feet, or about two miles) below the ocean’s surface on a small hill near the base of Davidson Seamount, an extinct underwater volcano 130 kilometers (80 miles) southwest of Monterey, California. The site is full of Muusoctopus robustus — a species MBARI researchers nicknamed the pearl octopus because from a distance, nesting individuals look like opalescent pearls on the seafloor.

Over the course of 14 dives with MBARI’s remotely operated vehicle (ROV) Doc Ricketts, the research team learned why such large numbers of pearl octopus are attracted to this location. The presence of adult male and female octopus, developing eggs, and octopus hatchlings indicated that the site is used exclusively for reproduction. The team did not observe any intermediate-sized individuals or any evidence of feeding. Pearl octopus gather at this site solely to mate and nest.

When researchers from NOAA and Nautilus Live first discovered the Octopus Garden, they observed “shimmering” waters. This phenomenon occurs when warm and cool waters mix, suggesting the region had previously unknown thermal springs. Further investigation by MBARI researchers and their collaborators confirmed octopus nests are clustered in crevices bathed by hydrothermal springs where warmer waters flow from the seafloor.

The ambient water temperature at 3,200 meters (10,500 feet) deep is 1.6 degrees Celsius (about 35 degrees Fahrenheit). However, the water temperature within the cracks and crevices at the Octopus Garden reaches nearly 11 degrees Celsius (about 51 degrees Fahrenheit).

Octopuses are ectotherms, or cold-blooded animals. The frigid temperatures of the deep sea slow their metabolism as well as their rate of embryonic development. Most deep-sea octopuses have very long incubation periods compared to their relatives inhabiting warmer shallow seas. Past experiments have measured egg incubation time for a number of octopus species in habitats and locations around the world. Comparing those egg incubation times clearly demonstrates how temperature affects the rate of embryo development — the colder the water, the slower the embryos grow.

At the near-freezing temperatures of the abyss, researchers expected pearl octopus eggs to take five to eight years, if not longer, to hatch. A 4K camera on MBARI’s ROV Doc Ricketts provided a close-up look at nesting mothers. MBARI researchers and their collaborators used the scars and other distinguishing features of individual octopus moms to monitor the development of their broods. Surprisingly, the eggs hatched in less than two years. Warmth from thermal springs increased the metabolism of female octopus and their broods, reducing the time required for incubation.

Researchers believe the shorter brood period in warmer waters greatly reduces the risk that developing octopus embryos will be injured or eaten by predators. Nesting in warmer water boosts the reproductive success of the pearl octopus, better ensuring the offspring’s survival.

“The deep sea is one of the most challenging environments on Earth, yet animals have evolved clever ways to cope with frigid temperatures, perpetual darkness, and extreme pressure. Very long brooding periods increase the likelihood that a mother’s eggs won’t survive. By nesting at hydrothermal springs, octopus moms give their offspring a leg up,” said Barry.

The massive number of octopus in one area attracts both predators and scavengers. Like most other cephalopods, pearl octopus die after they reproduce. Dead octopus at the Octopus Garden provide a feast for scavengers. A rich community of invertebrates lives alongside the nesting females, undoubtedly benefiting from unhatched eggs, vulnerable hatchlings, or adult octopus that have died.

Davidson Seamount and its Octopus Garden are protected as part of Monterey Bay National Marine Sanctuary. Previous MBARI expeditions to Davidson Seamount in 2002 and 2006 revealed the stunning community of life on its rocky slopes. MBARI’s images and video of beautiful deep-sea corals, vibrant sponges, and curious fishes engaged and inspired audiences worldwide. Ocean champions spoke up to protect this unique, and still untouched, ocean wilderness. In 2008, resource managers expanded the Monterey Bay National Marine Sanctuary to include Davidson Seamount.

“Essential biological hotspots like this deep-sea nursery need to be protected,” said Barry. “Climate change, fishing, and mining threaten the deep sea. Protecting the unique environments where deep-sea animals gather to feed or reproduce is critical, and MBARI’s research is providing the information that resource managers need for decision-making.”

This work is funded as part of the David and Lucile Packard Foundation’s long-term support of MBARI’s ocean research and technology.

Background

For more than two decades, researchers from MBARI and NOAA have collaborated to study Davidson Seamount. Since the first expedition to the seamount in 2002, NOAA has leveraged MBARI expertise in marine geology and benthic biology and ecology to develop a comprehensive research program that aims to understand the unique community of life on and around Davidson Seamount. Now, Davidson Seamount is considered one of the best-studied and well-protected seamounts in the world.

In October 2018, a team of researchers from NOAA, the Ocean Exploration Trust, and collaborators made an expedition to Davidson Seamount aboard the E/V Nautilus. At the suggestion of MBARI geologists and NOAA researchers, the Nautilus Live team decided to expand their exploration from the top of the seamount to its surrounding foothills. The researchers discovered thousands of octopus aggregated around a rocky ridge adjacent to the towering seamount.

Most of the octopus were oriented upside down, inverting their arms and folding them around their bodies. This posture was an indication of pearl octopus (Muusoctopus robustus) mothers protecting, or brooding, their eggs. The pearl octopus is a pale purple species about the size of a grapefruit that occurs in the northeastern Pacific Ocean from Oregon to Baja California. MBARI has observed this species at depths of 2,300 to 3,600 meters (7,500 to 11,800 feet).

MBARI researchers and their collaborators deployed a suite of advanced scientific instruments developed by MBARI engineers to better understand the Octopus Garden.

“The expertise of the MBARI team — the engineers, pilots of our submersible vehicles, and crew of our research vessels — was integral to studying this hotspot of life two miles below the surface. We leveraged decades of experience in deep-sea exploration to develop and deploy instruments to study the Octopus Garden without disturbing the nesting mothers,” said Barry.

MBARI’s ROV Doc Ricketts recorded high-definition and 4K video of the brooding pearl octopus and their neighbors. MBARI’s skilled submersible pilots maneuvered the ROV close to brooding pearl octopus to deploy instruments to measure the environmental conditions within their nests, including temperature and oxygen levels, and to film mothers and their eggs up close in ultra-high definition resolution. A stereoscopic camera allowed MBARI engineers to visualize sites within the Octopus Garden in 3D. The team also launched one of MBARI’s autonomous underwater vehicles to map the Octopus Garden at meter-scale resolution.

MBARI engineers outfitted the ROV Doc Ricketts with an innovative, custom-built sensor suite, the Low-Altitude Survey System (LASS), to see the Octopus Garden in even greater detail.

The LASS gathered detailed bathymetry information to help researchers characterize the seafloor habitat at centimeter-scale resolution. The LASS also took high-resolution photographs of the Octopus Garden. Researchers assembled these photographs into a photomosaic to count the number of nests within this deep-sea nursery. They documented 5,718 octopus within a 2.5-hectare (6.2-acre) area at the center of the Octopus Garden. The team estimated the total population of the 333-hectare (823-acre) hillock could easily exceed 20,000 individuals.

A time-lapse camera collected long-term observations of the octopus’ behavior and changes in the community over a period of more than six months, allowing researchers to keep watch on the octopus nursery between research expeditions. The camera recorded an image every 20 minutes and amassed a trove of more than 12,200 images from March 2022 to August 2022. These photographs revealed various activities and behaviors of octopus, their predators, and local scavengers.

Both male and female pearl octopus migrate to the Octopus Garden. Females search for a warm nesting spot to deposit a clutch of approximately 60 elongate, sausage-shaped eggs. When brooding, mothers cover their eggs with their body and protect them from predators that creep too close. She lives off food reserves from her own tissues while tending to her developing eggs.

The transformation from egg to hatchling is not easy. In addition to going through development successfully, embryos must avoid injury, predation, infection, and other external sources of mortality. Maternal care protects them from most external risks, but a shorter brooding period generally allows more eggs to survive.

As is typical of cephalopods, male and female pearl octopus die after reproducing — the Octopus Garden will be their final resting spot. Most females live until their eggs have hatched. Sometimes, however, a mother octopus runs out of energy and dies before her eggs complete their development, exposing the developing eggs to greater risk.

The time-lapse camera revealed that nesting mothers push aside the carcasses of dead octopus. Food is scarce in the deep sea and nothing goes to waste. Larger scavengers like rattail fishes (family Macrouridae), cusk eels (family Ophidiidae), whelks, and sea anemones feast on octopus remains. Near Davidson Seamount, life on the deep seafloor depends on the rain of organic matter from above. Researchers estimated the turnover of male octopus and nesting females to calculate how much nutrition this massive aggregation provides. Biomass from dying octopus represents a substantial carbon subsidy to the local seafloor community, providing 72 percent more food than is available outside the Octopus Garden.

Many questions still remain about the Octopus Garden, including where pearl octopus go after hatching, how this octopus species became adapted to breeding in thermal springs, how adult octopus find the thermal springs, what advantage individuals breeding in these hydrothermal springs have over those that breed elsewhere, and how common hydrothermal springs are in the deep sea.

The deep sea is not immune to threats like fishing, pollution, and climate change. By documenting deep-sea biodiversity and identifying hotspots of life on the ocean floor, scientists are gathering important information that resource managers can use to guide protections for this unique environment and its inhabitants.

“Technological advances in our ability to study the ocean have helped us discover and document incredible biodiversity across an array of deep-sea environments. As the imprint of human activities reaches deeper into ocean ecosystems, we need to protect not only the octopus nurseries found off California and Costa Rica, but also the many other biological treasures that remain undiscovered,” emphasized Barry.

Deep-sea octopus nurseries: A new field of exploration

Researchers have documented four deep-sea octopus nurseries to date — two off the coast of Central California and two off the coast of Costa Rica — and are continuing to study these sites to learn more about octopus behavior.

December 2013: Discovery of first octopus nursery at Dorado Outcrop (Costa Rica) Researchers from the University of Akron, the Field Museum, and the University of Alaska Fairbanks observed an aggregation of more than 100 octopus at the Dorado Outcrop, a hydrothermal spring located approximately 160 kilometers (100 miles) off the Pacific coast of Costa Rica at a depth of 3,000 meters (9,800 feet). The team identified the octopus as a potentially undescribed species of Muusoctopus. Nearly all of the individuals were in a brooding position, however, none of the eggs that researchers observed were viable.

April 2018: Researchers publish findings from the Dorado Outcrop (Costa Rica) The team of researchers from the University of Akron, the Field Museum, and the University of Alaska Fairbanks published their observations of deep-sea octopus brooding unviable eggs at the Dorado Outcrop in Deep Sea Research Part I.

October 2018: Discovery of second octopus nursery at the Octopus Garden (Davidson Seamount, United States) During a Nautilus Live expedition with the E/V Nautilus, researchers from NOAA’s Monterey Bay National Marine Sanctuary, the Ocean Exploration Trust, and collaborators observed a large aggregation of brooding octopus on a hillock approximately 12 kilometers (7.5 miles) southeast of Davidson Seamount at a depth of 3,200 meters (10,500 feet). Researchers identified the octopus as Muusoctopus robustus. A second visit by researchers from NOAA and the Woods Hole Oceanographic Institution (WHOI) in March 2019 confirmed the presence of warm hydrothermal springs at this site. The expedition team also confirmed that the octopus were brooding viable eggs and observed baby octopus hatching from the eggs.

April 2019: First MBARI expedition to Octopus Garden (Davidson Seamount, United States) MBARI researchers made their first visit to the Octopus Garden as part of the 2019 Seafloor Ecology expedition. Along with collaborators, they visited the site 14 times with the R/V Western Flyer between April 2019 and August 2022. Additionally, MBARI researchers visited the Octopus Garden with the R/V Rachel Carson in February 2022 to launch a mapping autonomous underwater vehicle and create meter-scale maps of the site.

October 2019: Discovery of third octopus nursery at Octocone (Davidson Seamount, United States) During a Nautilus Live expedition with the E/V Nautilus, researchers from NOAA, the Ocean Exploration Trust, and collaborators observed a second aggregation of brooding octopus on a volcanic cone to the east of Davidson Seamount. This site is approximately 17 kilometers (10.5 miles) northeast of the Octopus Garden. Researchers identified the octopus as Muusoctopus robustus. The octopus were confirmed to be brooding viable eggs.

June 2023: Discovery of fourth octopus nursery (Costa Rica) During a Schmidt Ocean Institute expedition with the R/V Falkor (too), researchers from the Bigelow Laboratory for Ocean Sciences and the University of Costa Rica observed a previously unknown octopus nursery near an unexplored and still-unnamed seamount off the Pacific coast of Costa Rica. Upon returning to the nearby Dorado Outcrop, the team also observed octopus brooding viable eggs, confirming this location is indeed an active octopus nursery. Both Costa Rican nurseries host a potentially undescribed species of Muusoctopus.

August 2023: MBARI researchers publish findings from the Octopus Garden (Davidson Seamount, United States) MBARI researchers and their collaborators from NOAA, Moss Landing Marine Laboratories, the University of Alaska Fairbanks, the University of New Hampshire, and the Field Museum published their research on brooding pearl octopus in Science Advances, confirming that deep-sea octopus migrate to the Octopus Garden to mate and nest.