Understanding the exposure of the nation’s living marine resources such as shellfish and corals to changing ocean chemistry is a primary goal for the NOAA OAP. Repeat hydrographic surveys, ship-based surface observations, and time series stations (mooring and ship-based) in the Atlantic, Pacific, and Indian Oceans have allowed us to begin to understand the long-term changes in carbonate chemistry in response to ocean acidification.
When the ocean absorbs carbon dioxide, chemical reactions create hydrogen ions that act like free agents, able to react with other compounds. Two ways we track ocean acidification are through pH and total alkalinity (TA). pH is a measure of how many free hydrogen ions are in the seawater. The more carbon dioxide in the ocean, the more these free agents are created, causing lower pH (more acidic).
The partial pressure of CO2 (pCO2) tells us how much carbon dioxide is in seawater. This information helps us understand ocean carbonate chemistry and biological productivity in the region. pCO2 increases when the ocean absorbs more CO2 from the atmosphere with elevated emissions.
Alkalinity is the ocean’s buffering system against increasing acidity. Total alkalinity is a measure of the concentration of buffering molecules like carbonate and bicarbonate in the seawater that can neutralize acid.
Dissolved inorganic carbon (DIC) tells us how much non-biological carbon is in seawater. Inorganic carbon comes in three main forms that we measure for DIC: carbon dioxide (CO2), bicarbonate (HCO3-), and carbonate (CO32-). Understanding DIC can help us determine the balance of carbonate forms in the ocean and the likelihood of ocean acidification.
There are currently 19 OAP-supported buoys in coastal, open-ocean and coral reef waters which contribute to NOAA's Ocean Acidification Monitoring Program, with other deployments planned.
Currently, there are two types of floating devices which instruments can be added in order to measure various ocean characteristics - buoys and wave gliders. Buoys are moored, allowing them to remain stationary and for scientists to get measurements from the same place over time. The time series created from these measurements are key to understanding how ocean chemistry is changing over time. There are also buoys moored in the open-ocean and near coral reef ecosystems to monitor the changes in the carbonate chemistry in these ecosystems. The MAP CO2 sensors on these buoys measure pCO2 every three hours.
Access our buoy data
Research cruises are a way to collect information about a certain ecosystem or area of interest.
For decades, scientists have learned about physical, chemical and biological properties of the ocean and coasts by observations made at sea. Measurements taken during research cruises can be used to validate data taken by autonomous instruments. One instrument often used on research cruises is a conductivity, temperature, and depth sensor (CTD), which measures the physical state of the water (temperature, salinity, and depth). The sensor often goes in the water on a rosette, which also carries niskin bottles used to collect water samples from various depths in the water column. Numerous chemical and biological properties can be measured from water collected in niskin bottles.
Ships of Opportunity (SOPs) or Volunteer Observing Ships (VOSs) are vessels at sea for other reasons than ocean acidification studies, such as commercial cargo ships or ferries.
The owners of these vessels allow scientific instrumentation that measures ocean acidification (OA) parameters to be installed and collect data while the ship is underway. This allows data on ocean chemistry to be collected in many remote areas of the world's ocean, such as high latitude waters, long distances from land (e.g. mid-basin waters), and places not easily accessible by research cruises. These partnerships have greatly increased the spatial coverage of OA monitoring world-wide. To learn more, check out the Ships of Opportunity programs established by the NOAA Pacific Marine Environmental Laboratory (PMEL) and the NOAA Atlantic Oceanographic Marine Laboratory (AOML).
Scientists at the NOAA Pacific Marine Environmental Laboratory (PMEL) are working with engineers at Liquid Robotics, Inc. to optimize a Carbon Wave Glider.
This instrument (pictured above) can be driven via satellite from land. Carbon Wave Gliders can be outfitted with pCO2, pH, oxygen, temperature and salinity sensors, and the glider’s equipment takes measurements as it moves through the water. The glider’s motion is driven by wave energy, and its sensors are powered through solar cells and batteries, when needed.
NOAA’s Coral Reef Conservation Program (CRCP) in partnership with OAP is engaged in a coordinated and targeted series of field observations, moorings and ecological monitoring efforts in coral reef ecosystems.
These efforts are designed to document the dynamics of ocean acidification (OA) in coral reef systems and track the status and trends in ecosystem response. This effort serves as a subset of a broader CRCP initiative referred to as the National Coral Reef Monitoring Plan, which was established to support conservation of the Nation’s coral reef ecosystems. The OAP contributes to this plan through overseeing and coordinating carbonate chemistry monitoring. This monitoring includes a broadly distributed spatial water sampling campaign complemented by a more limited set of moored instruments deployed at a small subset of representative sites in both the Atlantic/Caribbean and Pacific regions. Coral reef carbonate chemistry monitoring is implemented by researchers at the NOAA Atlantic Oceanographic & Meteorological Laboratory (AOML) and NOAA's PIFSC Coral Reef Ecosystems Division.
Effects of OA on Alaskan and Arctic fishes: physiological sensitivity in a changing ecosystem
Why we care
There is significant concern about ocean acidification disrupting marine ecosystems, reducing productivity of important fishery resources, and impacting the communities that rely upon those resources. To predict the ecological and socioeconomic impacts of acidification, it is critical to understand the complex interactions between environmental stressors of physiology and ecology of marine fishes. Previous work on Alaskan groundfish focused on direct physiological effects of OA on early life stages. We need to further this work to understand the interaction between OA and co-stressors like elevated temperatures on fish productivity.
What we are doing
This AFSC project examines the interactive effects of OA and elevated temperatures on three fish species that are critical to Alaska and Arctic fisheries: Pacific cod, Arctic cod, and yellowfin sole. Laboratory experiments will track the impact of OA exposure on adult Arctic cod reproductive output, egg quality, and larval production. Further experiments will consider the potential for within-generation and trans-generational acclimation and adaptation to environmental changes. Risk assessments for regional fisheries will incorporate the data from this project.
Benefits of our work
Findings from this research will provide the foundation necessary to evaluate the ecological and socioeconomic impacts of ocean acidification in Alaskan and Arctic waters.
Resiliency and sensitivity of marine fish to elevated CO2: osmoregulatory neurosensory behavioral and metabolic responses in salmon and sablefish
Why we care
Elevated levels of marine carbon dioxide can disrupt how many marine fishes detect their environment, impairing their ability to respond appropriately to chemical, auditory, and visual cues. The mechanisms underlying differences in species sensitivity and resilience are poorly understood. This NWFSC project will explore the mechanisms underlying differences in carbon dioxide sensitivity between marine species that occupy habitats with different carbonate chemistries.
What we are doing
We will compare regulatory capabilities and behavioral responses of sablefish and salmon to improve our understanding of how future fish populations may adapt to changing ocean chemistries. Our primary objectives are to build on existing OA infrastructure and previous research at the Northwest Fisheries Science Center to determine: 1) the mechanisms underlying sablefish resilience to low pH waters, and 2) the potential behavioral and physiological impacts of low pH exposure in pink and Chinook salmon.
Benefits of our work
Pacific salmon and sablefish are key species in the marine ecosystems of the western United States. They are an integral part of the history, culture, and economy of the West Coast and Alaska. This research advances our understanding of impacts of OA on salmon and sablefish behaviors and sensory systems. Findings enable fishery managers and scientific partners to identify species, populations, and geographic areas of concern. Ultimately, project results will inform managers about the resiliency and sensitivity of salmon to OA and assist their efforts for conservation priorities.
Sustained Observations of Ocean Acidification in Alaska Coastal Seas
Why we care
Coastal regions around Alaska experience some of the most rapid and extensive progressions of ocean acidification (OA) in the United States. Assessments indicate that Alaska coastal communities have a varying degree of vulnerability to OA ranging from moderate to severe. Economically vital fishing regions are the most vulnerable. Sustained monitoring is critical to track the extent and impact of ocean acidification in habitats that are home to sensitive species such as red king crab in the Bering Sea.
What we are doing
This project “rethinks” the coastal Alaskan OA monitoring effort (initiated in 2015) by sampling Alaska waters directly through the annual population survey program of the Alaska Fisheries Science Center (AFSC). This new vision doubles the spatial footprint of Alaska OA observations, increases the time resolution of these observations, and complements shipboard surveys in Alaska. Carbonate chemistry samples will be combined with fisheries population surveys to assess OA in the habitats of keystone organisms in the Bering Sea and Gulf of Alaska.
Benefits of our work
This project enhances our understanding of how the accumulation of anthropogenic carbon dioxide affects the seasonal progression of carbonate carbonate chemistry variables in the Gulf of Alaska. The observations can also be used to validate new OA models developed for the Gulf of Alaska and Bering Sea. Additionally, it can be applied to bioeconomic forecast models of crab and walleye pollock providing insight on how to adapt and build resilience to impacted industries and communities.