About

Adam Martiny is a professor whose lab studies the highly diverse microbial community living in the ocean. His research focuses on quantifying how global human-induced environmental changes affect microbial diversity and ecosystem functions. Marine microorganisms are recognized as the engines driving the cycles of carbon, nutrients, and oxygen in the ocean, and his work aims to understand how shifts in microbial communities influence processes such as CO2 uptake and oxygen levels in the ocean. His lab employs an interdisciplinary approach that integrates culture experiments, genomics and other ‘omics, big data analysis, and modeling. The lab is actively involved in ocean-going research expeditions through initiatives like Bio-GO-SHIP. The research conducted by Adam Martiny and his team contributes to understanding the impact of human activities on marine microbial ecosystems and global biogeochemical cycles.

Research topics

• Geology
• Environmental science
• Ecology
• Biology
• Oceanography
• Paleontology
• Geography
• Earth science

Selected publications

• Model code and output for "Decoupled timescales of organic carbon and phosphorus recycling in the global ocean"

  Figshare · 2026-01-01

  otherOpen accessSenior author

  Model code, output, and preprocessed input datasets supporting the publication: Sullivan, M.R., Primeau, F.W., Seo, H., Camps-Castellà, J., Inomura, K., &amp; Martiny, A. (2026) Decoupled timescales of organic carbon and phosphorus recycling in the global ocean, <i>PNAS</i>, 123, e2514991123. https://doi.org/10.1073/pnas.2514991123The src directory contains the biogeochemical model that couples the cycling of phosphorus, carbon, and oxygen. The postproc directory contains all MATLAB scripts used to analyze the output and create the figures presented in the publication.The outputs of the model optimization and sensitivity runs are saved in individual .mat files in the output directory. The model output data include: model grid information, model parameters, and 3D fields of dissolved inorganic phosphorus, dissolved organic phosphorus, particulate organic phosphorus, dissolved inorganic carbon, dissolved organic carbon (labile, semi-labile, refractory), particulate organic carbon, alkalinity, particulate inorganic carbon, and oxygen.For each model solution, the sequestration flux partitioned by residence time is stored in the rtime_dist_output directory.

  PublisherDOI

• Model code and output for "Decoupled timescales of organic carbon and phosphorus recycling in the global ocean"

  Open MIND · 2026-01-01

  otherSenior author

  Model code, output, and preprocessed input datasets supporting the publication: Sullivan, M.R., Primeau, F.W., Seo, H., Camps-Castellà, J., Inomura, K., &amp; Martiny, A. (2026) Decoupled timescales of organic carbon and phosphorus recycling in the global ocean, <i>PNAS</i>, 123, e2514991123. https://doi.org/10.1073/pnas.2514991123The src directory contains the biogeochemical model that couples the cycling of phosphorus, carbon, and oxygen. The postproc directory contains all MATLAB scripts used to analyze the output and create the figures presented in the publication.The outputs of the model optimization and sensitivity runs are saved in individual .mat files in the output directory. The model output data include: model grid information, model parameters, and 3D fields of dissolved inorganic phosphorus, dissolved organic phosphorus, particulate organic phosphorus, dissolved inorganic carbon, dissolved organic carbon (labile, semi-labile, refractory), particulate organic carbon, alkalinity, particulate inorganic carbon, and oxygen.For each model solution, the sequestration flux partitioned by residence time is stored in the rtime_dist_output directory.

  DOI

• Long‐Term Reorganization of Ocean Nutrient Distribution

  AGU Advances · 2026-02-26

  articleOpen access1st authorCorresponding

  Abstract Nutrient availability is a major driver of ocean biodiversity and productivity, yet long‐term global changes remain poorly constrained. Using over 14 million nitrate and phosphate measurements collected between 1925 and 2025, we quantify long‐term trends in nutrient concentrations across ocean biomes and depths. We find that surface waters in oligotrophic and mesotrophic regions show significant declines in phosphate, whereas nitrate is also slightly decreasing in oligotrophic but increasing in mesotrophic regions. Many coastal areas exhibit nutrient enrichment. Subsurface waters reveal widespread nitrate accumulation, suggesting an imbalance driven by biological nitrogen fixation and reduced vertical mixing. Comparison with Earth system models indicates that current simulations underestimate the pace of nutrient shifts. Our results highlight a large‐scale biogeochemical reorganization of ocean nutrient distributions that may intensify under future climate warming.

  PublisherDOI

• MICDOCv2.0 model code for UVic ESCM 2.10

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-14

  datasetOpen access

  Supplement to: Enhanced carbon storage in dissolved organic matter in a future oligotrophic oceanTakasumi Kurahashi-Nakamura, Thorsten Dittmar, Adam C. Martiny, Sinikka T. LennartzbioRxiv 2026.04.02.716036; doi: https://doi.org/10.64898/2026.04.02.716036

  PublisherDOI

• Spatial Patterns and Regulation of Nanomolar‐Level Nutrients in the Surface Oligotrophic Oceans

  Global Biogeochemical Cycles · 2026-04-01

  articleOpen access

  Abstract Ambient nutrient concentrations and their ratios regulate phytoplankton physiology and biomass in the ocean. In oligotrophic surface waters, nitrate and ammonium (NH 4 ) concentrations are often below conventional analytical detection limits (50–100 nM). However, nanomolar‐level nutrients can strongly influence phytoplankton growth in oligotrophic regions. Using highly sensitive colorimetry with detection limits of 3 nM, we quantified surface nitrate plus nitrite (NO X ), NH 4 , and phosphate (PO 4 ) concentrations across the low‐latitude Pacific and Indian Oceans. Concentrations from over 47,648 measurements were analyzed. NO X , NH 4 , and PO 4 ranged from ≤3 nM to several hundred nM, and after calculations of mean NO X , NH 4 , and PO 4 into 0.5° latitude‐longitude intervals, ∼60% of intervals for NO X and NH 4 showed &lt;5 nM, and ∼80% of them showed &lt;10 nM. Spatial PO 4 patterns were significantly associated with phosphacline depths, highlighting the importance of vertical PO 4 supply. The spatial NO X pattern was weakly associated with nitracline depth, and several to tens of kilometers processes, including upwelling and rainfall, contribute to its elevations. The combined NO X + NH 4 to PO 4 ratio was consistently below Redfield ratios. Subtle increases in NO X and/or NH 4 concentrations corresponded to slight increases in chlorophyll a levels, suggesting that both recycled and newly supplied nitrogenous nutrients contribute to phytoplankton biomass in oligotrophic low‐latitude oceans. Overall, our findings emphasize that highly sensitive nanomolar‐scale nutrient analyses are important for understanding the environmental controls on phytoplankton in low‐latitude oligotrophic oceans.

  PublisherDOI

• MICDOCv2.0 model code for UVic ESCM 2.10

  Zenodo (CERN European Organization for Nuclear Research) · 2026-04-14

  datasetOpen access

  Supplement to: Enhanced carbon storage in dissolved organic matter in a future oligotrophic oceanTakasumi Kurahashi-Nakamura, Thorsten Dittmar, Adam C. Martiny, Sinikka T. LennartzbioRxiv 2026.04.02.716036; doi: https://doi.org/10.64898/2026.04.02.716036

  PublisherDOI

• Genomic-to-space measurements reveal large-scale ocean nutrient stress

  DRYAD · 2026-02-10

  datasetOpen access1st authorCorresponding

  Global ocean phytoplankton growth and primary production are intimately linked to nutrient fluctuations from seasonal to millennial time scales. Rapid recycling compromises the utility of surface nutrient or phytoplankton stocks for delineating the biogeography of global ocean nutrient stress. Here, field-measured hydrography and ‘omics biomarkers of nutritional status are coupled to a satellite remote sensing metric of cell physiology to mechanistically evaluate monthly to multi-decadal shifts in global phytoplankton nutrient stress. We observe a clear biogeography in nutrient stress aligned with variations in the nutricline depth and distinctly elevated stress in nitrogen- compared to phosphate-limited waters. Regions where cells are switching to rare forms of alternative nutrients are most stressed. Temporal modes of stress are dominated by seasonal changes, but strong signatures of natural climate cycles are also apparent. Surface ocean warming over the last twenty years has led to broad increases in nutrient stress with one notable exception. Southern hemisphere oligotrophic regions experienced declines in nutrient stress that we attribute to changes in ocean nitrogen fixation. Our integrated hydrography, genomic, and satellite remote sensing of phytoplankton physiology has uncovered contemporary changes in global phytoplankton nutrient stress.

  PublisherDOI

• Decoupled timescales of organic carbon and phosphorus recycling in the global ocean

  Proceedings of the National Academy of Sciences · 2026-02-17 · 1 citations

  articleOpen accessSenior author

  The ocean’s biological carbon pump exports atmospheric CO 2 to the deep ocean, where it can remain sequestered for decades to centuries, and attempts to artificially enhance this natural carbon sink by fertilizing portions of the open ocean could help mitigate the impacts of excessive anthropogenic CO 2 emissions. However, differences in the cycling rates of carbon and other nutrients may impact the long-term response to ocean fertilization. In this study, we use a steady-state global biogeochemical inverse model, optimized to match hydrographic observations, to examine how differential production, remineralization, and circulation-driven re-exposure timescales of organic carbon and phosphorus affect long-term carbon sequestration. We partition global organic matter production based on the time required for regenerated carbon and phosphorus to return to the ocean surface. We find that less than 15% of total organic carbon and 31% of total organic phosphorus production remains sequestered in the ocean interior for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mo>≥</mml:mo> </mml:math> 1 y, with only 3.3% (1.8 Pg C y −1 ) and 8.3% (0.046 Pg P y −1 ), respectively, remaining for a century or longer. The C:P ratio of the sequestration flux declines with increasing residence time, from 255:1 for total production to 98:1 for material sequestered for 100+ years, indicating that carbon is recycled to the surface more rapidly than phosphorus. This decoupling between carbon and phosphorus sequestration timescales could result in a “productivity hangover,” where the slow recovery of surface phosphate leads to a long-term suppression of global productivity, reducing the net removal of atmospheric CO 2 .

  PublisherDOI

• Enhanced carbon storage in dissolved organic matter in a future oligotrophic ocean

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-04-02

  articleOpen access

  Abstract Marine dissolved organic carbon (DOC) is one of the ocean’s largest carbon reser-voirs, which persists for millennia and exceeds the carbon stored in terrestrial and marine biomass combined (Hansell et al, 2012; Dittmar et al, 2021; Moran et al, 2022). Yet its response to climate change remains uncertain, largely because the ecological mechanisms behind its microbial degradation are poorly understood (Wagner et al, 2020; Legendre et al, 2015; Lønborg et al, 2020). Here we show how observed global-scale distribution of DOC emerges from bottom-up ecological controls acting on microbial DOC consumers. We combined large-scale metagenomic data (Larkin et al, 2021) with incubation experiments (Hale et al, 2017) to map global patterns of nutrient limitation in heterotrophic microbial communities responsible for DOC uptake. We then integrated a new microbial–DOC component into an Earth system model, which successfully reproduced observed global distributions of nutrient stress and DOC concentrations. Linking carbon and nutrient cycles reveals quantitatively significant consequences for the future ocean. Under a highemission scenario (SSP5-8.5), the DOC pool is projected to increase by 18–44 gigatons by 2200. This increase, driven by intensified nutrient limitation in surface waters, contributes substantially to the biological carbon pump, accounting for about ∼ 30% of the increase in deep-ocean carbon storage associated with particulate organic carbon export. Overall, our results indicate that the marine DOC reservoir is more dynamic than previously thought. Reduced DOC remineralisation in an increasingly oligotrophic ocean constitutes a quantitatively significant negative feedback on centennial timescales.

  PublisherOA PDFDOI

• Biochemical future of marine ecosystems

  Nature Climate Change · 2026-03-31

  article1st authorCorresponding
  PublisherDOI

Recent grants

• Quantifying ocean oxygen-to-carbon demand by chemical analyses and inverse models

  NSF · $779k · 2020–2023

• Convergence: RAISE: Linking the adaptive dynamics of plankton with emergent global ocean biogeochemistry

  NSF · $999k · 2018–2022

• Collaborative Research: Interactive physiological controls of trait expression, nutrient allocation, and the elemental stoichiometry of Synechococcus

  NSF · $624k · 2022–2026

• Dimensions: Collaborative research: Biological controls of the ocean C:N:P ratios

  NSF · $1.0M · 2011–2016

• Collaborative Research: The stoichiometric trait distribution of the marine microbiome

  NSF · $280k · 2022–2026

Frequent coauthors

• Alyse A. Larkin

  56 shared

• Michael W. Lomas

  Bigelow Laboratory for Ocean Sciences

  56 shared

• Steven D. Allison

  University of California, Irvine

  56 shared

• Jennifer B. H. Martiny

  University of California, Irvine

  46 shared

• Allison R. Moreno

  University of California, Santa Cruz

  35 shared

• Catherine A. Garcia

  University of Hawaiʻi at Mānoa

  33 shared

• Kathleen K. Treseder

  University of California, Irvine

  31 shared

• Nathan S. Garcia

  30 shared