MBARI Autonomous Robots Reveal Daily Rhythms of Microbial Activity in Open Ocean Eddies
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A research team from MBARI, the University of Montana, and the University of Hawaiʻi at Mānoa has used MBARI's long-range autonomous underwater vehicles to reveal how microbial communities and ocean biogeochemistry vary over daily cycles in remote open ocean eddies. The findings, published in Nature Communications, demonstrate how autonomous robotic platforms equipped with advanced sampling and genomics capabilities are transforming the study of microbial activity and biogeochemical cycling in some of the ocean's most dynamic and inaccessible environments.
Strategic Significance of the Research
Microbial communities play an outsized role in ocean function, driving oxygen production and underpinning the ocean's biogeochemical cycles, including the carbon, nitrogen, and nutrient flows that regulate marine ecosystems. Despite their importance, the dynamics of microbial populations in open ocean environments have historically been difficult to study because of the dynamic and variable nature of offshore conditions and the operational challenges of sustained sampling at sea. The MBARI-led research demonstrates how autonomous platforms can address these constraints, providing the persistent observational presence needed to capture microbial activity at the temporal resolution required to understand its biological and biogeochemical drivers.
LRAUV Capability and Operational Profile
MBARI's long-range autonomous underwater vehicle is a versatile tool for open ocean science, equipped with advanced instruments and intelligent algorithms that allow it to detect and follow temperature and salinity fronts and phytoplankton blooms. When outfitted with MBARI's Environmental Sample Processor, the vehicle can collect samples for advanced genomics analyses, revealing the metabolic activity of microbes over time as they drift through the sea. The combination of autonomous navigation, environmental sensing, and onboard sample processing transforms the vehicle into a mobile laboratory capable of operating in remote regions for extended periods, generating data of a kind that would be prohibitively expensive to collect through conventional ship-based campaigns.
2018 Schmidt Ocean Institute Expedition
The research is based on a 2018 expedition led by the Schmidt Ocean Institute, during which two LRAUVs were deployed to autonomously track and sample deep phytoplankton blooms in the productive twilight waters of cyclonic eddies offshore of the northern Hawaiian islands. The deployment leveraged the unique capability of LRAUVs to follow biological features through three-dimensional space, allowing researchers to study microbial communities as they evolved within their natural physical and chemical environment. The use of two coordinated LRAUVs further enhanced the spatial and temporal resolution of the data, providing one of the most detailed observational datasets available on open ocean microbial activity at the eddy scale.
Diel Rhythms in Microbial Activity
The research reveals how microbial gene expression and biogeochemical processes vary over daily cycles in response to physical and chemical drivers. Diel rhythms in microbial activity have important implications for the timing of carbon export, oxygen production, and nutrient cycling, all of which are central to the ocean's role in the global climate system. Capturing these rhythms in their natural setting requires high-frequency sampling over extended periods, an observational capability that has historically been beyond the reach of conventional research platforms. The MBARI study demonstrates that autonomous robotic platforms can deliver this capability with scientific rigour, opening up new pathways for understanding microbial behaviour in remote and dynamic ocean environments.
Cyclonic Eddies as Biological Hotspots
Cyclonic eddies play an important role in open ocean productivity, drawing nutrients from deeper waters into the sunlit upper layers and supporting elevated levels of biological activity. The selection of these features as the focus of the LRAUV deployment reflects their biological and biogeochemical significance, as well as the challenge of studying them with traditional methods. Eddies are mobile, three-dimensional features that evolve over days to weeks, and tracking their internal dynamics requires sustained presence and adaptive sampling. By demonstrating that LRAUVs can autonomously locate, follow, and sample these features, the research provides a template for future studies of similar phenomena across the global ocean.
Integration of Robotics, Sensing, and Genomics
A defining feature of the study is the integration of multiple advanced technologies into a single observational system. The LRAUV provides the autonomous navigation and operational endurance, the Environmental Sample Processor enables in situ sample collection and preservation, and downstream genomics analyses translate the collected samples into detailed information about microbial gene expression and metabolic activity. This integration represents a significant maturation of ocean robotics from platforms primarily focused on physical and chemical sensing toward systems capable of supporting complex biological and biogeochemical research at scale. The combination is increasingly central to advances in ocean science, where the most important questions often require the integration of multiple data streams collected continuously over extended periods.
Implications for Climate and Biogeochemical Modelling
Microbial activity is a foundational input into the global carbon, oxygen, and nutrient cycles that regulate Earth's climate system. Improved understanding of how microbial communities behave in remote ocean environments strengthens the empirical foundation of climate and biogeochemical models, supporting more accurate projections of how the ocean's role in climate regulation will evolve under continued anthropogenic pressure. As models become more sophisticated and computational capabilities expand, the demand for high-quality observational data on microbial dynamics is rising, and autonomous platforms such as the LRAUV are emerging as one of the most promising mechanisms for meeting that demand.
Continuous Monitoring as a New Standard
Autonomous robots can operate continuously across vast and remote regions, helping scientists uncover patterns and processes that have historically been hidden by the limitations of traditional research platforms. MBARI technology is transforming the practice of ocean monitoring from sporadic snapshots of marine life and processes to a persistent presence in the ocean. The shift has profound implications for ocean science, since many of the most important biological and biogeochemical processes occur on time scales that are difficult to capture through episodic ship-based sampling. Continuous observational presence enables a more accurate, integrated picture of how the ocean functions, and supports the broader effort to monitor ocean health in a rapidly changing climate.
Implications for the Ocean Technology Sector
The publication of the Nature Communications study reinforces the trajectory of ocean technology toward integrated, autonomous, and scientifically powerful platforms. As governments, research institutions, and increasingly the private sector look to expand observational coverage of the ocean, demand for capabilities such as those demonstrated by MBARI is expected to rise. Applications extend well beyond microbial research, encompassing fisheries science, biodiversity monitoring, climate research, and operational applications such as offshore industry environmental compliance. Each successful demonstration of advanced autonomous capability strengthens the commercial and scientific case for continued investment in this area, supporting the broader maturation of the ocean technology sector.
Outlook for Autonomous Ocean Science
The MBARI work points to a future in which autonomous platforms become a standard component of large-scale ocean science programmes rather than specialised tools used in selected research projects. As LRAUVs and similar systems become more capable, more affordable, and more widely available, the population of institutions able to deploy them will grow, expanding the volume and quality of data available to support climate, biological, and biogeochemical research. For the broader ocean economy, the implications are significant, since improved understanding of ocean processes underpins more credible carbon accounting, more effective marine conservation, and more informed decisions about offshore activities ranging from fisheries management to renewable energy development. The Nature Communications study provides one of the most compelling current examples of how autonomous ocean technology is enabling that transition.
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This article was contributed by an external writer affiliated with our publication.
