Until further notice, OCB will not be able to consider bulk travel support requests.
We will post an announcement if this changes.
Until further notice, OCB will not be able to consider bulk travel support requests.
We will post an announcement if this changes.
The Ocean Observatories Initiative (OOI) is a science-driven ocean observing network that delivers real-time data from multiple coastal and open-ocean arrays to address critical science questions regarding the world’s oceans. During each array service cruise OOI performs hydrographic sampling to evaluate and validate the deployed instrumentation. Service cruises are conducted annually for the open ocean arrays and every six months for the coastal arrays. This repeat sampling has created time series of valuable physical, chemical, and biological information. Water samples from Niskin bottles on CTD casts are analyzed either on the ship or in onshore labs to measure oxygen, salinity, nutrients (nitrate, nitrite, silicate, phosphate, ammonium), chlorophyll, and the carbon system (pH, dissolved inorganic carbon, total alkalinity).
FIGURE 1
OOI launched a collaboration in 2023 with the Biological & Chemical Oceanography Data Management Office (BCO-DMO) to make OOI water sampling data available via the BCO-DMO website and ERDDAP server. BCO-DMO curates publicly available research-ready oceanographic data in accordance with FAIR data principles. Advantages of distributing OOI data through BCO-DMO include concatenation of the cruise-by-cruise data into a single dataset with a Digital Object Identifier (DOI) and provisioning through ERDDAP, which provides both human and machine-to-machine interfaces. The BCO-DMO Dataset pages include descriptions of sampling and processing methods, and README files for each cruise.
Currently BCO-DMO has data from the OOI Station Papa Array (Gulf of Alaska, annual cruises over 11 years), Irminger Sea Array (North Atlantic, 10 years), Southern Ocean Array (SW of Chile, 6 years) and Argentine Basin Array (South Atlantic, 4 years). You can access the datasets via this direct link or from the BCO-DMO home page: Click on Projects, then search for “OOI Discrete CTD and Water Sampling Cruise Data”.
FIGURE 2
Figures 1 and 2 provide an example of the concatenated datasets using 10 years of data from the Irminger Sea Array. A Python script (implemented in a Jupyter Notebook available in https://github.com/WHOIGit/ooi-on-bco-dmo ) was used to access the data from the BCO-DMO ERDDAP server, extract variables of interest, apply available quality control (QC) flags, and visualize the data. Figure 1 shows profiles of selected variables for successive cruises to give a sense of the depth-time data coverage. Note that the sample depths are relatively sparse since the OOI sampling goal is to validate instruments on the moorings rather than collect comprehensive profile data. Figure 2 represents profile variability over time by an overplot color-coded by year.
Even though constrained to “Acceptable” QC flags, some of the values plotted appear to be outliers, indicating the need for the user to consider further data quality assessment. Note that Discrete README files within the BCO-DMO dataset and CTD Cast Logs on OOI’s Raw Data Archive provide useful information. For example, the low values of oxygen in 2021are noted as inconsistent with oxygen from the CTD cast, whereas the high values of salinity in 2015 appear to be real, associated with a salinity maximum observed by the CTD. Since creating the Jupyter Notebook, data for two of the Irminger Sea cruises in OOI’s Raw Data Archive have been updated (including Nitrate for the 2021 cruise); these updates will be in the next version of the Irminger Sea dataset on BCO-DMO.
For additional Python scripts to explore OOI Discrete CTD and Water Sampling Cruise Data as distributed by BCO-DMO, for example to plot a discrete parameter against its corresponding CTD sensed parameter, see notebooks available in https://github.com/WHOIGit/ooi-on-bco-dmo/tree/main/notebooks .
The Surface Ocean-Lower Atmosphere Study (SOLAS) and the Observing Air-Sea Interactions Strategy (OASIS) are formalising a collaborative partnership to advance and deepen scientific understanding of ocean-atmosphere interactions. This partnership merges SOLAS’s long-standing expertise in biogeochemical and physical processes with OASIS’s leadership in physical flux observations and operational oceanography, enabling a comprehensive, interdisciplinary approach to observing, modeling, and understanding the dynamic air-sea interface.
Through this affiliation, OASIS will become an officially recognised partner in the upcoming SOLAS 2026–2035 science plan, while SOLAS will designate liaisons to the OASIS Scientific Steering Committee. Together, the two programs will co-develop integrated strategies from small-scale process studies to Earth System Model improvements and capacity building in the Global South to joint participation in significant international efforts such as the UN Decade of Ocean Science for Sustainable Development.
Key areas of collaboration include:
• Air-sea transition zone physical-biogeochemical process studies
• Integration of physical and biogeochemical satellite and in situ observational datasets
• Parameterisation of ocean-atmosphere interactions in coupled climate models
• Advancing Earth System Modeling through constrained air-sea flux estimates
• Support for early career researchers via training, liaisons, and interdisciplinary capacity-building programs
The partnership also includes a shared commitment to public engagement, standardised methodologies, and developing educational resources and events such as workshops, town halls, and curriculum initiatives. Regular meetings and representation on each other’s governance structures will ensure ongoing coordination, communication, and community alignment.
SOLAS and OASIS will work together to enhance the global impact of air-sea research by creating a more connected and solution-oriented scientific community.
Read the joint statement of collaboration here.
We welcome feedback on the statement here.
OCB2025 Plenary Sessions
Constraining the dark ocean carbon cycle: Implications for ocean carbon budgets? (Co-chairs: Anne Dekas, Anela Choy, Jeff Bowman, Randie Bundy)
Rivers to coasts: Biogeochemical linkages and environmental resilience (joint with North American Carbon Program) (Co-chairs: Fei Da, Kanchan Maiti, Shaily Rahman, Libby Larson, David Butman)
Rapidly changing systems (Co-chairs: Kristen Krumhardt, Rachel Stanley, Melissa Melendez)
Bridging scales in the ocean carbon cycle (Co-chairs: Zachary Erickson, Tim DeVries, Roo Nicholson, Daniel Whitt, Dreux Chappell)
The Leaky Deltas OCB workshop was held 17-20 March 2025 at Louisiana State University, in Baton Rouge, USA, which is situated within the Mississippi River delta. We brought together 57 members of the research community who study river deltas in the context of the global carbon cycle. The goal of the workshop was to create a community consensus on the state of delta carbon cycle science, identify critical knowledge gaps, and brainstorm opportunities and priorities for future research efforts. Participants ranged in career stage from graduate student to senior scientist, and from disciplines ranging from biogeochemistry to geomorphology, river scientists to oceanographers; and scientists using a variety of methodological approaches.
The workshop included five oral sessions, four breakout sessions, numerous opportunities for discussion over meals and coffee breaks, a trip to the LSU Center for River Studies, and a workshop dinner. The breakout sessions were formatted to encourage discussion among interdisciplinary groups of scientists at different career stages. During breakout session 1, participants were randomly assigned to groups that spanned career stages and expertise. This session was aimed at identifying grand challenges in delta carbon cycle science. Breakout session 2 had a disciplinary focus, where we broke out into groups of biogeochemistry, geomorphology, modeling, and ecosystems. Breakout session 3 was broken out into groups based on physical domains of the delta: river, wetlands, subaqueous delta, shelf, and continental slope. A highlight of day three was a field trip to the LSU Center for River Studies, where workshop participants were guided on a tour of the historical changes of the Mississippi River Delta, as well as the large-scale physical model of the delta. On the fourth and final day of the workshop, we had short break-out sessions and reconvened as a whole to synthesize ideas and circle back to the workshop objectives.
In summary, the workshop resulted in a consensus on the key knowledge gaps and research grand challenges, which included constraining the composition of organic matter, the timescales of geomorphic processes, biogeochemical reaction rates, impacts of human perturbations and extreme events, and challenges in monitoring deltaic processes. Workshop participants now have the task of writing a position paper that summarizes these grand research challenges, identifies the data needed to address these challenges, and recommends a framework and directions for future research. One outcome of the workshop included the structure and organization for this paper. The early career workshop participants will also lead an early-career-led perspective paper that discusses ideas for integrating new technologies and methodologies to address these grand challenges and identifies future challenges for the delta science community.
Ombres, E., H. Benway, K. Bisson, A. Larkin, L. Perotti, L. Wright-Fairbanks (eds.) (2024). Connecting Observations to Models: Biogeochemical Observing and Modeling Workshop, 2024 Summary Report and Suggested Steps Forward. Published Date: 2024 Series: NOAA technical memorandum OAR-OAP ; 6, DOI: https://doi.org/10.25923/wpdj-ja69
How deep in the ocean do microbes feel the effects of nutrient limitation? Microbial production in one third of the surface ocean is limited by the essential micronutrient iron (Fe). This limitation extends to at least the bottom of the euphotic zone, but what happens below that?
In a study that recently published in Nature we investigated the abundance and distribution of siderophores, small metabolites synthesized by bacteria to promote Fe uptake. When environmental Fe concentrations become limiting and microbes become Fe deficient, some bacteria release siderophores into the environment to bind iron and facilitate its uptake. Siderophores are therefore a window into how microbes “see” environmental Fe. We found that siderophore concentrations were high in low Fe surface waters, but surprisingly we also found siderophores to be abundant in the twilight zone (200-500 m) underlying the North and South Pacific subtropical gyres, two key ecosystems for the marine carbon cycle. In shipboard experiments with siderophores labeled with the rare 57Fe isotope, we found rapid uptake of the label in twilight zone samples. After removing 57Fe from the 57Fe-siderophores complex, bacteria released the now unlabeled siderophores back into seawater to complex additional Fe (Figure. 1).
Figure 1: Iron-siderophore cycling in the twilight zone. When the seawater becomes Fe-deficient, some bacteria are able to synthesize siderophores and release them into the environment (middle left). These metabolites bind Fe (middle right) and the Fe-siderophore complex is taken up by bacteria using specialized TonB dependent transporters (TBDT; bottom right). Inside the cell, Fe is recovered from the Fe-siderophore complex (bottom left) and the siderophore excreted back into the environment to start the cycle anew.
Our results show that in large parts of the ocean microbes feel the effects of nutrient limitation deep in the water column, to at least 500 m. This greatly expands the region of the ocean where nutrients limit microbial metabolism. The effects of limitation this deep in the water column are unexplored, but twilight zone Fe deficiency could have unanticipated consequences for the efficiency of the ocean’s biological carbon pump.
Authors
Jingxuan Li, Lydia Babcock-Adams and Daniel Repeta
(all at Woods Hole Oceanographic Institution)
Denitrification is a crucial multi-step process for ecosystem productivity and sustainability because some of its steps can result in the loss of the essential nutrient nitrogen or the production of greenhouse gas nitrous oxide. We do not understand why microbial functional groups conducting different steps of denitrification can coexist in the ocean and why certain groups are more abundant than others.
In a recent study published in PNAS, we uncover ecological mechanisms that govern the coexistence of these microbes. For the microbial groups utilizing different nitrogen substrates, the “stronger” groups rely on the “weaker” groups to feed them nitrogen (with respect to the organic substrates that they compete for), enabling them to coexist. For the groups competing for the same nitrogen substrates, microbes that invest more to build longer denitrification steps win the competition when nitrogen is limiting, but lose the game when nitrogen is repleted and organic carbon is limiting. The spatial and temporal variability of nutrients in the ocean allows these microbes to be observed in the same water mass.
Figure caption: Temporal and spatial heterogeneity in nutrients promotes the coexistence of functionally diverse denitrifiers in the ocean.
These hypothesized coexistence patterns help us predict where and when nitrogen loss and nitrous oxide production may occur. As human activities continue to alter marine nutrient balances, these predictions help us better anticipate ocean responses and design better strategies for mitigating negative anthropogenic impacts on the ocean.
Authors
Xin Sun (Carnegie Institution for Science) @xinsun-putiger.bsky.social
Emily Zakem (Carnegie Institution for Science) @carnegiescience.bsky.social
SOLAS Update — Newsletter April 2025
Launch of the SOLAS Europe Regional Panel
Biogeochemical models predict that ocean warming is weakening the vertical transport of nutrients to the upper ocean, with severe implications for marine productivity. However, nutrient concentrations across the ocean surface often fall below detection limits, making it difficult to observe long-term changes.
In a recent study in PNAS, we analyzed over 30,000 nitrate and phosphate depth profiles observed between 1972 and 2022 to quantify nutricline depths, where nutrient concentrations are reliably detected. These depths accurately represent nutrient supplies in a global model, allowing us to assess long-term trends. Over the past five decades, upper ocean phosphate has mostly declined worldwide, while nitrate has remained mostly stable. Model simulations support that this difference is likely due to nitrogen fixation replenishing upper ocean nitrate, whereas phosphate has no equivalent biological source.
Figure caption: Five decades of global and regional nutricline depth data reveal declining phosphate-to-nitrate trends. Nutricline depths were defined based on threshold concentrations of 3 μmol kg−1 nitrate (TNO3) and 3/16 μmol kg−1 phosphate (TPO4). Site-specific trends were quantified for each unique pair of geographic coordinates where sufficient data was available (TNO3, n = 1,859 sites; TPO4, n = 1,641 sites). Shown are 95% confidence intervals (CI95%) calculated for each median trend by generating 10,000 bootstrap samples. The curves over the histograms depict the kernel densities. The sets of error bars from top to bottom are the interquartile ranges of TNO3 and TPO4 from a monthly climatology, the total observations, and the total observations with added measurement error.
These findings suggest that the ocean is becoming more limited in phosphorus. This decline could make phytoplankton less nutritious for marine animals. Fish larvae growth rates correlate with phosphorus availability in the ecosystem, so intensifying phosphorus limitation may greatly impact fisheries worldwide.
Authors
Skylar Gerace (University of California, Irvine)
Jun Yu (University of California, Irvine)
Keith Moore (University of California, Irvine)
Adam Martiny (University of California, Irvine)
@UCI_OCEANS
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Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.