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Research Regions

Open Ocean

Open ocean research is aimed at evaluating the vulnerability of regions in deep waters beyond the continental shelf to future ocean acidification caused by natural variability and human-caused changes.

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Studying OA in the open ocean to improve observing technology

Acidification research in the open ocean can provide information for national and international policy and adaptive actions, food security, fisheries and aquaculture practices, protection of coral reefs, shore protection, cultural identity, and tourism. The primary goals of open ocean research are to determine how carbon and pH changes interact with natural variability to collectively act on ocean carbonate chemistry and biology that matters to people. In turn, NOAA’s contributions with technological development with new sensors, autonomous platforms and innovating with co-locating biological and physical and chemical studies continues to support NOAA as a global leader and provide critical information to the Global Ocean Acidification Observing Network (GOA-ON). These efforts and observations help validate models and calibrate satellite data synthesis products. Global maps and data synthesis products provide information.

View FULL Research Plan (PDF)

Tracking progress of ocean acidification research in the Open Ocean

Open Ocean Map
The Open Ocean Region

The research goals in the Open Ocean Region are to:

  • Maintain existing observations and continue developing and deploying autonomous vehicles and biogeochemical (BGC) Argo floats to measure surface and water column carbon parameters, nutrients, and other Essential Ocean Variables (EOVs)
  • Conduct biological sampling (e.g., Bongo net tows) during GO-SHIP cruises to determine the biological impacts of OA and other stressors on planktonic communities
  • Develop data management systems and synthesis products including visualizations of key chemical and biological parameters to quantify anthropogenic carbon dioxide (CO2) buildup, rates of change of global ocean ocean acidification conditions, and biological rate processes
  • Support data synthesis activities to provide validation of biogeochemical models.

The following charts represent the mid-point progress in implementing research actions that focus on the Open Ocean Region according to the NOAA Ocean, Coastal, and Great Lakes Acidification Research Plan.

NOAA invests in research and activities toward meeting goals that improve our ability to understand and predict environmental change, species and ecosystem to response to changing ocean chemistry, and the human impacts of these changes. The report card below summarizes progress over the past five years toward meeting these goals for the Open Ocean Region, measured by the number of major actions toward meeting this goal: good progress (4+ actions), some progress (1-3 actions) and no known progress.

Good overall progress

Some progress

No known progress

Environmental Change

There are 11 environmental change actions: 10 have good overall progress and one has no known progress.

Biological Sensitivity

There are four biological sensitivity actions: all have made some progress.

Human Dimensions

There are three human dimension actions: one has made some progress and two have no known progress.

Featured Research Projects

Environmental Change
Covering the Globe with GO-SHIP
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Environmental Change
The Importance of Extremes in U.S. Waters
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Biological Sensitivity
Biotic Calcification
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OAP Funded Projects

Plankton bloom seen from space. Credit: NASA
Multiscale observing system simulation experiments for iron fertilization in the Southern Ocean, Equatorial Pacific, and Northeast Pacific
  • PI(s): Dennis McGillicuddy
  • Fiscal Year Funded: 2023, 2024, 2025
  • Grant Award # NA23OAR0170514
This project will address the effectiveness of ocean iron fertilization as a carbon dioxide removal technique, identify potential unintended ecological consequences, and determine the necessary systems for monitoring carbon and..
Project Summary >
The colder water assemblage of foraminifera. T. quinqueloba, N. incompta and G. falconensis are common. Credit: NOAA Fisheries
Determining the Influence of Ocean Alkalinity Enhancement on Foraminifera Calcification, Distribution, and Calcium carbonate Production
  • PI(s): Laura Haynes
  • Fiscal Year Funded: 2023, 2024, 2025, 2026
  • Grant Award # NA23OAR0170513
This project examines the effects of different materials used in ocean alkalinity enhancement on foraminifera...
Project Summary >
Air-Sea Interaction Spar buoy. Credit: Lt. Elizabeth Crapo, NOAA Corps
Data requirements for quantifying natural variability and the background ocean carbon sink in mCDR models
  • PI(s): Galen McKinley
  • Fiscal Year Funded: 2023
This project will better quantify the air-sea carbon dioxide exchange on a regional scale...
Project Summary >
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Latest Publications

Biological Responses to Ocean Acidification Are Changing the Global Ocean Carbon Cycle
  • R. C. Barrett, B. R. Carter, A. J. Fassbender, B. Tilbrook, R. J. Woosley, K. Azetsu-Scott, R. A. Feely, C. Goyet, M. Ishii, A. Murata, F. F. Pérez
  • Global Biogeochemical Cycles
  • March 24, 2025
Citation: Barrett, R. C., Carter, B. R., Fassbender, A. J., Tilbrook, B., Woosley, R. J., Azetsu-Scott, K., Feely, R. A., Goyet, C., Ishii, M., Murata, A., & Pérez, F. F. (2025). Biological Responses to Ocean Acidification Are Changing the Global Ocean Carbon Cycle. Global Biogeochemical Cycles. https://doi.org/10.1029/2024GB008358
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Global Carbon Budget 2024
  • Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Judith Hauck, Peter Landschützer, Corinne Le Quéré, Hongmei Li, Ingrid T. Luijkx, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Almut Arneth, Vivek Arora, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Carla F. Berghoff, Henry C. Bittig, Laurent Bopp, Patricia Cadule, Katie Campbell, Matthew A. Chamberlain, Naveen Chandra, Frédéric Chevallier, Louise P. Chini, Thomas Colligan, Jeanne Decayeux, Laique M. Djeutchouang, Xinyu Dou, Carolina Duran Rojas, Kazutaka Enyo, Wiley Evans, Amanda R. Fay, Richard A. Feely, Daniel J. Ford, Adrianna Foster, Thomas Gasser, Marion Gehlen, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Jens Heinke, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Andrew R. Jacobson, Atul K. Jain, Tereza Jarníková, Annika Jersild, Fei Jiang, Zhe Jin, Etsushi Kato, Ralph F. Keeling, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Xin Lan, Siv K. Lauvset, Nathalie Lefèvre, Zhu Liu, Junjie Liu, Lei Ma, Shamil Maksyutov, Gregg Marland, Nicolas Mayot, Patrick C. McGuire, Nicolas Metzl, Natalie M. Monacci, Eric J. Morgan, Shin-Ichiro Nakaoka, Craig Neill, Yosuke Niwa, Tobias Nützel, Lea Olivier, Tsuneo Ono, Paul I. Palmer, Denis Pierrot, Zhangcai Qin, Laure Resplandy, Alizée Roobaert, Thais M. Rosan, Christian Rödenbeck, Jörg Schwinger, T. Luke Smallman, Stephen M. Smith, Reinel Sospedra-Alfonso, Tobias Steinhoff, Qing Sun, Adrienne J. Sutton, Roland Séférian, Shintaro Takao, Hiroaki Tatebe, Hanqin Tian, Bronte Tilbrook, Olivier Torres, Etienne Tourigny, Hiroyuki Tsujino, Francesco Tubiello, Guido van der Werf, Rik Wanninkhof, Xuhui Wang, Dongxu Yang, Xiaojuan Yang, Zhen Yu, Wenping Yuan, Xu Yue, Sönke Zaehle, Ning Zeng, and Jiye Zeng
  • Earth System Science Data
  • March 14, 2025
Citation: Friedlingstein, P., O’Sullivan, M., Jones, M. W., Andrew, R. M., Hauck, J., Landschützer, P., Le Quéré, C., Li, H., Luijkx, I. T., Olsen, A., Peters, G. P., Peters, W., Pongratz, J., Schwingshackl, C., Sitch, S., Canadell, J. G., Ciais, P., Jackson, R. B., Alin, S. R., Arneth, A., Arora, V., Bates, N. R., Becker, M., Bellouin, N., Berghoff, C. F., Bittig, H. C., Bopp, L., Cadule, P., Campbell, K., Chamberlain, M. A., Chandra, N., Chevallier, F., Chini, L. P., Colligan, T., Decayeux, J., Djeutchouang, L. M., Dou, X., Duran Rojas, C., Enyo, K., Evans, W., Fay, A. R., Feely, R. A., Ford, D. J., Foster, A., Gasser, T., Gehlen, M., Gkritzalis, T., Grassi, G., Gregor, L., Gruber, N., Gürses, Ö., Harris, I., Hefner, M., Heinke, J., Hurtt, G. C., Iida, Y., Ilyina, T., Jacobson, A. R., Jain, A. K., Jarníková, T., Jersild, A., Jiang, F., Jin, Z., Kato, E., Keeling, R. F., Klein Goldewijk, K., Knauer, J., Korsbakken, J. I., Lan, X., Lauvset, S. K., Lefèvre, N., Liu, Z., Liu, J., Ma, L., Maksyutov, S., Marland, G., Mayot, N., McGuire, P. C., Metzl, N., Monacci, N. M., Morgan, E. J., Nakaoka, S.-I., Neill, C., Niwa, Y., Nützel, T., Olivier, L., Ono, T., Palmer, P. I., Pierrot, D., Qin, Z., Resplandy, L., Roobaert, A., Rosan, T. M., Rödenbeck, C., Schwinger, J., Smallman, T. L., Smith, S. M., Sospedra-Alfonso, R., Steinhoff, T., Sun, Q., Sutton, A. J., Séférian, R., Takao, S., Tatebe, H., Tian, H., Tilbrook, B., Torres, O., Tourigny, E., Tsujino, H., Tubiello, F., van der Werf, G., Wanninkhof, R., Wang, X., Yang, D., Yang, X., Yu, Z., Yuan, W., Yue, X., Zaehle, S., Zeng, N., and Zeng, J.: Global Carbon Budget 2024, Earth Syst. Sci. Data, 17, 965–1039, https://doi.org/10.5194/essd-17-965-2025, 2025.
Read Summary >
Site-Specific Multiple Stressor Assessments Based on High Frequency Surface Observations and an Earth System Model
  • Elise M. B. Olson, Jasmin G. John, John P. Dunne, Charles Stock, Elizabeth J. Drenkard, Adrienne J. Sutton
  • Earth and Space Science
  • July 22, 2024
Citation: Olson, E. M. B., John, J. G., Dunne, J. P., Stock, C., Drenkard, E. J., & Sutton, A. J. (2024). Site-specific multiple stressor assessments based on high frequency surface observations and an Earth system model. Earth and Space Science, 11, e2023EA003357. https://doi.org/10.1029/2023EA003357
Read Summary >
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Get involved with ocean acidification

The NOAA Ocean Acidification Program exists to meet the ocean acidification research and monitoring needs of the U.S. See how you can get involved to serve your community and participate in cutting-edge research and education and outreach. 

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Covering the Globe with GO-SHIP

Map of GO-SHIP tracks from November 2024
Credit: GO-SHIP

The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) network consists of 55 sustained hydrographic sections that provide global open ocean measurements of the highest accuracy. These hydrographic cruises span ocean basins from coast to coast and sea surface to seafloor to monitor changes in inventories of heat, freshwater, carbon, oxygen, nutrients and transient tracers on decadal timescales. The scientific efforts on GO-SHIP cruises produce carbon system studies, data for model calibration and validation, and calibration and deployment of autonomous sensing equipment such as Argo floats and surface drifters, among other contributions. Between 2021-2024, U.S. GO-SHIP completed or have funded cruises A20, A22, P02, A16N, I05, A13.5, I08S, ARC01 and A16S, that collectively sailed in the Atlantic, Pacific, Indian and Arctic Oceans. With support from NOAA, the National Science Foundation and international partners, GO-SHIP cruises contribute significantly to our understanding of open ocean acidification.

Importance of Extremes to U.S. Waters

Visualization of ocean water temperatures on a map
Image credit: NOAA CPO

Multiple stressors increasingly impact the world’s oceans and marine ecosystems. Extremes in these stressors have the potential to exacerbate ecosystem effects, particularly in coastal regions where changes can be magnified. Using a fully-coupled Earth System Model, GFDL-ESM4.1, run under a range of scenarios developed for the 6th phase of the Coupled Model Intercomparison Model (CMIP6), this project quantified the relationship between oceanic long term changes and extremes in individual and compound stressors with particular focus on U.S. territorial waters and Marine Protected Areas. Comparing model historical simulations with available time series observations in these areas helped identify the required observations for detecting and attributing these stressors. While the results of this study highlighted areas of improvement for model-observation agreement, they also showed that monthly 1-degree global model output (publicly available from CMIP6) can be useful in the context of extreme event analysis. This work was funded by OAP in cooperation GFDL and the GOMO.

Biotic calcification impacts on marine carbon dioxide removal additionality

Pteropod shells thinning due to ocean acidification
Image Credit: NOAA

The global ocean is a large natural sink for carbon, having absorbed approximately 30% of carbon dioxide over the last few centuries. This fact has inspired research on the feasibility of various marine carbon dioxide removal (mCDR) approaches that aim to enhance natural uptake, leading to changing ocean chemistry impacting marine life and people who depend on healthy ecosystems. One scientific uncertainty regarding certain mCDR techniques is the potential increase in precipitation and export of calcium carbonate minerals by calcifying organisms in response to increases in carbonate mineral saturation states induced by the approaches. This in turn could decrease the efficiency of these techniques. This project led by researchers at the University of Washington aims to quantify the magnitude and uncertainty of this feedback on mCDR additionality through the use of a small model ensemble driven by industry-informed mCDR scenarios. The results will inform the growing mCDR market.

Bioeconomic modeling to inform Alaska fisheries management

Fishing Dock in Juneau Alaska
Image credit: Allen Shimada, NOAA NMFS

Bioeconomic models are a multidisciplinary tool that use oceanography, fisheries science and social science to assess socioeconomic impacts. Funded by the Ocean Acidification Program, researchers at the Alaska Fisheries Science Center use a bioeconomic model to study the impacts of ocean acidification on Eastern Bering Sea crab, northern rock sole and Alaska cod. The goal is to predict how ocean acidification will affect abundance yields and income generated by the fisheries. This work informs the potential economic impacts of ocean acidification and future decision making and research planning.

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Effects of ocean acidification and temperature on Alaskan crabs

Red King Crab
Image credit: David Csepp, NMFS AKFSC ABL

Long-term declines of red king crab in Bristol Bay, Alaska may be partially attributed to ocean acidification conditions. These impacts may be partially responsible for the fishery closures during the 2021–2022 and 2022–2023 seasons. Researchers found that ocean acidification negatively impacts Alaskan crabs generally by changing physiological processes, decreasing growth, increasing death rates and reducing shell thickness. Funded by the Ocean Acidification Program, scientists at the Alaska Fisheries Science Center continue to investigate the responses of early life history stages and study the potential of various Alaska crabs to acclimate to changing conditions. Results will inform models that will use the parameters studied to predict the effects of future ocean acidification on the populations of red king crab in Bristol Bay as well as on the fisheries that depend on them. Fishery managers will better be able to anticipate and manage stocks if changing ocean chemistry affects stock productivity and thus the maximum sustainable yield.

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Forecasts for Alaska Fisheries

Crab pots and fishing nets in Alaska's Dutch Harbor
Image credit: Michael Theberge

Understanding seasonal changes in ocean acidification in Alaskan waters and the potential impacts to the multi-billion-dollar fishery sector is a main priority. Through work funded by NOAA’s Ocean Acidification Program, the Pacific Marine Environmental Laboratory developed a model capable of depicting past ocean chemistry conditions for the Bering Sea and is now testing the ability of this model to forecast future conditions. This model is being used to develop an ocean acidification indicator provided to fisheries managers in the annual NOAA Eastern Bering Sea Ecosystem Status Report.

ADAPTING TO OCEAN ACIDIFICATION

The NOAA Ocean Acidification Program (OAP) works to prepare society to adapt to the consequences of ocean acidification and conserve marine ecosystems as acidification occurs. Learn more about the human connections and adaptation strategies from these efforts.

Adaptation approaches fostered by the OAP include:

FORECASTING

Using models and research to understand the sensitivity of organisms and ecosystems to ocean acidification to make predictions about the future, allowing communities and industries to prepare

Closeup of oysters cupped in someone's hands

MANAGEMENT

Using these models and predictions as tools to facilitate management strategies that will protect marine resources and communities from future changes

TECHNOLOGY DEVELOPMENT

Developing innovative tools to help monitor ocean acidification and mitigate changing ocean chemistry locally

REDUCING OUR CARBON FOOTPRINT

50 more ways to reduce your carbon footprint >

On the Road

Drive fuel-efficient vehicles or choose public transportation. Choose your bike or walk! Don't sit idle for more than 30 seconds. Keep your tires properly inflated.

With your Food Choices

Eat local- this helps cut down on production and transport! Reduce your meat and dairy. Compost to avoid food waste ending up in the landfill

With your Food Choices

Make energy-efficient choices for your appliances and lighting. Heat and cool efficiently! Change your air filters and program your thermostat, seal and insulate your home, and support clean energy sources

By Reducing Coastal Acidification

Reduce your use of fertilizers, Improve sewage treatment and run off, and Protect and restore coastal habitats

TAKE ACTION WITH YOUR COMMUNITY

You've taken the first step to learn more about ocean acidification - why not spread this knowledge to your community?

Every community has their unique culture, economy and ecology and what’s at stake from ocean acidification may be different depending on where you live.  As a community member, you can take a larger role in educating the public about ocean acidification. Creating awareness is the first step to taking action.  As communities gain traction, neighboring regions that share marine resources can build larger coalitions to address ocean acidification.  Here are some ideas to get started:

  1. Work with informal educators, such as aquarium outreach programs and local non-profits, to teach the public about ocean acidification. Visit our Education & Outreach page to find the newest tools!
  2. Participate in habitat restoration efforts to restore habitats that help mitigate the effects of coastal acidification
  3. Facilitate conversations with local businesses that might be affected by ocean acidification, building a plan for the future.
  4. Partner with local community efforts to mitigate the driver behind ocean acidification  – excess CO2 – such as community supported agriculture, bike & car shares and other public transportation options.
  5. Contact your regional Coastal Acidification Network (CAN) to learn how OA is affecting your region and more ideas about how you can get involved in your community
       More for Taking Community Action