September 22 - Metabarcoding webinar register
September 24 - SedMIP webinar register
November 18 - 20 Years of OCB Symposium register
Find more detail on upcoming and past OCB webinars here, and watch recordings on topical playlists on the OCB YouTube Channel.
What drives the year-to-year variability of dissolved oxygen (O2) in the tropical Pacific? A recent study explored this question using a global high-resolution model with active ocean biogeochemistry along with a machine learning based estimate of dissolved oxygen from Argo floats. El Niño and La Niña events play a major role in regulating the O2 content and distribution in the tropical Pacific. El Niño events result in excess O2 in the eastern tropical Pacific and reduced O2 in the west. La Niña yields opposite patterns. In contrast to previous speculations that lower model resolution leads to an underestimate of observed O2 variability in this region, we find little difference in the amplitude of the O2 content change between models of different resolution (~1º vs 0.1º) and the observations-based machine learning estimate. ENSO-driven variability of O2 in the eastern tropical Pacific is driven by large opposing physical and biological contributions: reduced upwelling of low-O2 waters and weaker O2 consumption at depth due to suppressed biological productivity during El Niño dominate over the reduction in O2 ventilation by vertical turbulent mixing and the Equatorial Undercurrent, and the opposite occurs during La Niña. This subtle balance between competing processes suggests that future changes in O2 in the tropical Pacific are likely to be sensitive to local changes in equatorial Pacific circulation and productivity, in addition to changes in large scale O2 supply from the mid and high latitude basins as the ocean warms and stratifies. These O2 changes have important implications for understanding and predicting marine ecosystem health and fisheries productivity throughout the tropical Pacific.
Figure: ENSO impacts on temperature and O2 shown as regression of Nino 3.4 index on a) temperature anomalies, and b) O2 anomalies in a high resolution simulation of CESM. Panel c) illustrates the main mechanisms governing the O2 response to El Niño events.
Authors
Yassir A. Eddebbar (Scripps Institution of Oceanography)
M L. Hoffman (Scripps Institution of Oceanography)
Jonathan D. Sharp (UW/NOAA)
Daniel B. Whitt (NASA Ames)
Aneesh C. Subramanian (CU Boulder)
Sam Stevenson (UC Santa Barbara)
@NCAR_CGD @CUBoulderATOC @Scripps_Ocean @aneeshcs @CLIVAR @USCLIVAR
Citation: Eddebbar, Y. A., Hoffman, E. L., Sharp, J. D., Whitt, D. B., Subramanian, A. C., & Stevenson, S. (2026). ENSO-Driven Variability of Oxygen Content and Distribution in the Tropical Pacific. Journal of Climate, 39(5), 1333-1353. https://doi.org/10.1175/JCLI-D-25-0476.1
What if a tiny amount of plastic could make the ocean’s carbon appear thousands of years older than it really is?
For decades, oceanographers have relied on routine measurements of particulate organic carbon to understand how carbon moves through the ocean, how long it persists, and how it shapes Earth’s climate. These measurements, based on combusting or oxidizing environmental samples and measuring the carbon released as CO₂, assume that the carbon being measured comes from natural biological sources. But what if that assumption is no longer safe?
Microplastics are now pervasive throughout the ocean, from coastal waters to the open sea. These tiny fragments originate from the breakdown of larger plastic debris or are manufactured directly for commercial and industrial uses. Once they enter marine systems through rivers, wastewater, or runoff, they mix seamlessly with natural particles and are easily captured during routine sampling of particulate organic matter. Critically, the analytical tools used to quantify carbon in these samples cannot distinguish plastic-derived carbon from carbon produced by living organisms.
In our study, we set out to test how much this hidden overlap matters. Using controlled experiments, we demonstrate that even very small amounts of fossil fuel–derived plastic can substantially bias standard measurements of organic matter composition. When microplastics contribute as little as ~1% of a sample’s mass, they introduce large isotopic errors, shifting Δ¹⁴C values by approximately −258‰ and δ¹³C values by −3.65‰. In radiocarbon terms, this translates into organic matter appearing roughly 4,000 years older than it actually is.
Figure: Relationship between δ¹³C, C:N, and radiocarbon (¹⁴C) age for sedimentary organic matter – polyethylene sediment admixtures. Colored boxes denote typical δ¹³C ranges of major carbon reservoirs (POC, DOC, terrestrial). Pie charts show measured positions of polyethylene admixtures (percent polyethylene by mass in parentheses), with yellow and blue sectors representing apparent marine and terrestrial contributions inferred from a two-endmember mixing model. Even 1% polyethylene contamination (red outline) substantially shifts apparent source attribution and radiocarbon age (red values). The black curve shows the modeled δ¹³C–C:N relationship
These findings reveal a quiet but consequential problem. Radiocarbon measurements are widely used to estimate how long carbon persists in the ocean and how resistant it is to degradation. If microplastics are inadvertently included in samples, natural organic carbon can appear artificially older and more stable than it truly is. Because most carbon biogeochemistry studies do not routinely account for the presence of microplastics, existing datasets and models may already be influenced by this contamination to unknown degrees.
Carbon isotope measurements are crucial for estimates of oceanic carbon budgets, inform climate models, and shape our understanding of how the ocean moderates atmospheric CO₂. If microplastics have been altering these measurements for years, then some interpretations of carbon cycling and climate feedbacks may need to be revisited. Recognizing microplastics not only as pollutants, but also as analytical interlopers, is an essential step toward improving the accuracy of ocean carbon science and ensuring that future observations reflect the ocean’s true biological signal.
Authors
Luis E. Medina Faull
Gordon T. Taylor
Steven R. Beaupré
(all at School of Marine and Atmospheric Sciences, Stony Brook University)
Citation: Medina Faull LE, Taylor GT, Beaupré SR (2025) Microplastic contaminants potentially distort our understanding of the ocean’s carbon cycle. PLoS One 20(10): e0334546. https://doi.org/10.1371/journal.pone.0334546
OCB will support participation in Cornell Summer Satellite Remote Sensing Workshop
June 1 – June 12, 2026, Cornell University, Ithaca New York
The Cornell Summer Satellite Remote Sensing Workshop is being offered once again this year. The workshop is highly methods-oriented and intended to give participants the practical skills needed to work independently to acquire, analyze and visualize large data sets derived from a wide range of ocean satellite sensors.
Strong emphasis is given to ocean color remote sensing and the use of NASA’s SeaDAS software to derive mapped imagery of geophysical parameters using satellite data derived from the most popular ocean color sensors. Pre-written python scripts will be used in conjunction with SeaDAS to enable processing large quantities of ocean color data from Level-1 to Level-3. In addition, the workshop will address the acquisition and use of Level-3 satellite data products for sea surface temperature, ocean wind speed and sea surface height.
A central goal of the course is to develop good python programming skills that are needed to make effective use of satellite data to routinely monitor ocean conditions, gain new insights into ocean dynamics, and to rigorously test new hypotheses. Participants will work with both Jupyter Notebooks and executing python scripts from the Unix Terminal.
For more information about the training workshop content and enrollment process:
Visit: http://oceanography.eas.cornell.edu/satellite
Email: Bruce Monger
OCB will provide tuition, housing, and a travel stipend for up to 4 US-based participants in this training course. Please send the following materials in a single formatted PDF file to hbenway@whoi.edu by April 13:
1) Abbreviated (2 pages max) CV
2) 1-page statement of interest about how this course would benefit your education, research, and/or professional goals.
Applications will be reviewed the week of April 13, and applicants will be notified the week of April 20.
The SOLAS Early Career Scientist Committee (ECSC) is pleased to announce the call for mentors for the first edition of the SOLAS Mentorship Programme, running from May 2026 to April 2027. This 12‑month pilot, aligned with the SOLAS 3.0 Science Plan, aims to foster real exchange across career stages and to support the professional growth of early-career scientists in our community.
Mentors will work with small, thematic groups of mentees through online group meetings over the year, email conversations, and participation in selected skill‑focused activities. More details of the programme structure, objectives, and commitments are available in the Terms of Reference.
We are particularly keen to hear from mentors who are engaged in SOLAS science, leadership, or community activities, and who reflect the diversity of regions, disciplines, and career paths across our network. We encourage early-career scientists who are interested in mentoring and community building to consider applying. The expected time commitment is around 4–6 hours per four‑month term, so that participation remains meaningful but manageable alongside other responsibilities.
If you are interested in taking part in this new community initiative, please submit an expression of interest via the online form: https://forms.gle/Dy1Pu8U7fF6K4pQf8. For those without access to Google Forms, please download the form and email your expression of interest to the SOLAS ECSC (solasecsc@xmu.edu.cn).
The deadline for submissions is 24 April 2026.
→Learn more about benthic modeling activities during the first SedMIP webinar on April 23 at 3pm – join us for a recap + summary of key points raised at the OSM26 town hall, intro to model inventory and model participation, and ways to get involved in this activity, we also are seeking speakers for this webinar series.
Sign up for updates, or to give a webinar talk
Take our short survey to inform the SedMIP activity by March 31
Learn more about this activity: https://www.us-ocb.org/sedmip/
How much organic carbon is actually transported to depth in the Southern Ocean and what are the mechanisms driving seasonal and regional variability? With large-scale remote sensing observations constrained to the surface and the depth-resolved ship-based measurements being scarce, the emergence of the BGC-Argo fleet has opened up a new avenue to explore how carbon is transported from the sunlit surface to the deep ocean.
Figure caption: Conceptual illustration of applying a broken power law to POC concentration profiles measured with BGC-Argo floats in the Southern Ocean. The “steepness” or strength of the attenuation is an indicator for how quickly POC attenuates. With the emergence of the BGC-Argo floats, the authors investigate spatial and temporal patterns and possible drivers.
In a recent study published in Communication Earth & Environment, the authors present an improved model to study particle attenuation and discuss what mechanism could explain it: mineral ballasting, zooplankton processes, temperature and net primary production. The work is based on the optical backscatter and chlorophyll-fluorescence observations from the BGC-Argo fleet that are converted into particulate organic carbon (POC) profiles. The float coverage allows us to investigate seasonal patterns and spatial variability across frontal zones and oceanic basins in attenuation strength by applying a power law to the measurements. The traditional version of the simple power law (“Martin curve”) was not able to capture the large variability in the mesopelagic. Instead, we propose a broken power law to better explain higher, observed attenuation coefficients in the upper water column.
This new empirical model for particle attenuation can help guide the experimental studies and model developments needed to help constrain the biological carbon pump and how it may change future emission scenarios.
Authors
Annika Oetjens (University of Tasmania, IMAS, ACEAS)
Tyler Rohr (University of Tasmania, IMAS, AAPP, ACEAS)
Peter Strutton (University of Tasmania, IMAS, ACEAS)
Zanna Chase (University of Tasmania, IMAS, ACEAS)
The paper provides a comprehensive synthesis of 68 existing ocean carbonate chemistry data products and data product sets, including cruise-based compilations, time-series datasets, gap-filled observational products, and model-based reconstructions. The authors highlight the diversity of available products, noting differences in spatial coverage, temporal resolution, methodologies, and intended scientific applications. By systematically cataloguing and comparing these datasets, the study helps researchers identify which products are most suitable for specific scientific questions related to ocean carbon cycling and ocean acidification.
Interface for the most updated list of products
Authors
Li-Qing Jiang (University of Maryland; NOAA National Centers for Environmental Information; Scripps Institution of Oceanography)
Amanda Fay (Columbia University / Lamont-Doherty Earth Observatory)
Jens Daniel Müller (ETH Zürich; Carbon to Sea Initiative)
Luke Gregor (ETH Zürich; Swiss Data Science Center)
Alizée Roobaert (Flanders Marine Institute, VLIZ)
Lydia Keppler (Vycarb Inc.)
Dustin Carroll (Moss Landing Marine Laboratories; NASA Jet Propulsion Laboratory)
Siv K. Lauvset (NORCE Research / Bjerknes Centre for Climate Research)
Tim DeVries (University of California, Santa Barbara)
Judith Hauck (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research)
Christian Rödenbeck (Max Planck Institute for Biogeochemistry)
Nicolas Metzl (Sorbonne Université / LOCEAN)
Andrea J. Fassbender (NOAA Pacific Marine Environmental Laboratory)
Jean-Pierre Gattuso (Sorbonne Université / CNRS; Laboratoire d’Océanographie de Villefranche)
Peter Landschützer (Max Planck Institute for Meteorology)
Rik Wanninkhof (NOAA Atlantic Oceanographic and Meteorological Laboratory)
Christopher Sabine (University of Hawaii at Mānoa)
Simone R. Alin (NOAA Pacific Marine Environmental Laboratory)
Mario Hoppema (Alfred Wegener Institute)
Are Olsen (University of Bergen / Bjerknes Centre for Climate Research)
Matthew P. Humphreys (University of East Anglia)
Kunal Chakraborty (National Institute of Oceanography, India)
Ana C. Franco (University of Miami)
Kumiko Azetsu-Scott (Bedford Institute of Oceanography / Fisheries and Oceans Canada)
Dorothee C. E. Bakker (University of East Anglia)
Leticia Barbero (NOAA Atlantic Oceanographic and Meteorological Laboratory)
Nicholas R. Bates (Bermuda Institute of Ocean Sciences / Arizona State University)
Nicole Besemer (University of Natural Resources and Life Sciences Vienna)
Henry C. Bittig (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Albert E. Boyd (University of Tasmania)
Daniel Broullón (Spanish Institute of Oceanography, IEO-CSIC)
Wei-Jun Cai (University of Delaware)
Brendan R. Carter (University of Washington)
Thi-Tuyet-Trang Chau (LSCE, CEA-CNRS-UVSQ)
Chen-Tung Arthur Chen (National Sun Yat-sen University)
Frédéric Cyr (Fisheries and Oceans Canada)
John E. Dore (University of Hawaii)
Ian Enochs (NOAA Atlantic Oceanographic and Meteorological Laboratory)
Richard A. Feely (NOAA Pacific Marine Environmental Laboratory)
Hernan E. Garcia (NOAA National Centers for Environmental Information)
Marion Gehlen (LSCE, CEA-CNRS-UVSQ)
Prasanna Kanti Ghoshal (CSIR-National Institute of Oceanography, India)
Lucas Gloege (Princeton University)
Melchor González-Dávila (University of Las Palmas de Gran Canaria)
Nicolas Gruber (ETH Zürich)
Debby Ianson (Fisheries and Oceans Canada / Institute of Ocean Sciences)
Yosuke Iida (Japan Meteorological Agency)
Masao Ishii (Meteorological Research Institute, Japan)
Apurva Padamnabh Joshi (CSIR-National Institute of Oceanography, India)
Esther Kennedy (NOAA Pacific Marine Environmental Laboratory)
Alex Kozyr (NOAA National Centers for Environmental Information)
Nico Lange (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Claire Lo Monaco (Sorbonne Université / LOCEAN)
Derek P. Manzello (NOAA Atlantic Oceanographic and Meteorological Laboratory)
Galen A. McKinley (Columbia University / Lamont-Doherty Earth Observatory)
Natalie M. Monacci (NOAA Pacific Marine Environmental Laboratory)
Xosé A. Padin (Spanish Institute of Oceanography, IEO-CSIC)
Ana M. Palacio-Castro (Instituto de Investigaciones Marinas, CSIC)
Fiz F. Pérez (Spanish Institute of Oceanography, IEO-CSIC)
J. Magdalena Santana-Casiano (University of Las Palmas de Gran Canaria)
Jonathan Sharp (University of Delaware)
Adrienne Sutton (NOAA Pacific Marine Environmental Laboratory)
Jim Swift (Scripps Institution of Oceanography)
Toste Tanhua (GEOMAR Helmholtz Centre for Ocean Research Kiel)
Maciej Telszewski (International Ocean Carbon Coordination Project, IOCCP)
Jens Terhaar (University of Bern)
Ruben van Hooidonk (University of Miami / NOAA Coral Reef Watch)
Anton Velo (Spanish Institute of Oceanography, IEO-CSIC)
Andrew J. Watson (University of Exeter)
Angelicque E. White (Oregon State University)
Zelun Wu (University of Delaware)
Liang Xue (Xiamen University)
Hyelim Yoo (University of Maryland / NOAA NCEI)
Jiye Zeng (National Institute for Environmental Studies, Japan)
Guorong Zhong (Xiamen University)
Ocean organisms transfer carbon via many natural processes from surface to seafloor. These include the passive sinking of carbon-rich particles and the active transport of carbon as animals swim downward. A recent study in GBC modeled how carbon stored in fish biomass moves from the sea surface to the seafloor in shelf–slope–abyssal systems through feeding interactions alone. This transport occurs as large fish eat smaller fish while occupying different vertical habitats in the water column. On average, this process delivers an amount equivalent to 5% of all carbon that reaches the seafloor—through sinking organic particles from phytoplankton and zooplankton. Yet, this can be as high as 20% in some shelf areas. On continental slopes, midwater fishes play a key role as a stepping-stone for carbon transfer (up to 50%) to the seafloor. Overall, the study reveals that the vertical movement of fish is an important pathway for delivering carbon to groundfish species, particularly on shelf areas where most commercially valuable fisheries operate.
Caption: Schematic of a shelf-slope-abyssal system with hypothesized fluxes of carbon among major functional groups (top panel); and model-estimated fluxes of carbon from functional groups to demersal fishes (bottom panel). Solid and dotted lines are mean fluxes for Eastern and Western North Atlantic systems, respectively, and shaded areas are standard deviations. Values are proportional.
Authors
Daniel Ottmann (Technical University of Denmark (DTU-Aqua); Institute of Marine Sciences of Andalusia)
Ken H. Andersen (Technical University of Denmark (DTU-Aqua))
Yixin Zhao (Technical University of Denmark (DTU-Aqua))
Colleen M. Petrik (Scripps Institution of Oceanography)
Charles A. Stock (Scripps Institution of Oceanography)
Clive Trueman (University of Southampton)
P. Daniël van Denderen (Technical University of Denmark (DTU-Aqua))
Follow the authors:
bluesky: @danielottmann.bsky.social; @kenandersen.bsky.social
LinkedIn accounts: Ottman; Andersen; Truman
X: @daniel_ottmann; @69kno; @OceanLifeCenter; @van_denderen; @clivetrue;
Active Transport of Carbon to Demersal Fish Communities in Shelf-Slope-Abyssal Systems of the North Atlantic Ocean
Global Biogeochemical Cycles, Vol 40:2, e2025GB008861. https://doi.org/10.1029/2025GB008861
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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.