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.
Forecast effects of ocean acidification on Alaska crab and groundfish fisheries
Why we care Ocean acidification (OA) is a multi-disciplinary problem that requires a combination of methods from oceanography, fisheries science, and social science to assess socio-economic impacts. While OA impact models developed to date capture some sources of measurement uncertainty, more remains and limits the utility of models in decision making and research planning. A method is needed to quantify uncertainty relating the experimental design of OA experiments to the impacts of ocean pH and temperature on key model outcomes.
What we are doing The bioeconomic model developed under this project will be applied to forecasting long-term effects of OA on Eastern Bering Sea (EBS) crab, northern rock sole and Alaska cod. Also addressed in this project is the quantification of uncertainty for inclusion in the fisheries management process. The overall goal for this project is to forecast long-term effects of OA on abundance yields and fishery income. To this end, we will apply results from experiments and ocean monitoring/modeling to infer population-scale changes in juvenile growth and survival from OA.
Benefits of our work Through development of bioeconomic models for the EBS and Gulf of Alaska, we will be able to forecast the long-term effects of OA on northern rock sole and Alaska cod – a fish providing the vast majority of U.S. cod. These models make it possible to estimate abundance yields, fishery income, and economic impacts of OA on a national scale. The results from the project can assist with the development of experiments that will be most informative for bioeconomic modeling.
Using next-generation sequencing techniques to assess adaptive capacity and illuminate mechanisms underlying the effects of high pCO2 on Alaskan crab and fish species
Why we care Many economically important crab and fish species are negatively affected by exposure to ocean acidification predicted to occur throughout their ranges in the coming decades. Ocean acidification results in decreased growth, altered development, weaker exoskeletons, increased energy outputs, altered immune systems, altered behavior, and increased mortality in some of these species. Other stressors such as increased temperature can have interactive negative effects when combined with ocean acidification. Traditional laboratory experiments cannot duplicate the gradual changes that will affect species populations over multiple life-history stages and generations, so using next-generation genetic approaches provide insight into effects beyond specific life stages.
What we are doing This study will use next-generation sequencing techniques to identify specific alterations in the molecular, metabolic, and physiological pathways of individuals exposed to ocean acidification. This is a way to identify pathways that impart tolerance to ocean acidification and warming. This project determines the effect of ocean acidification and thermal stress on gene expression in Pacific cod larvae and juvenile Tanner crab and identifies genetic markers indicating ocean acidification resilience.
Benefits of our work Investigators will identify the cellular pathways that impart tolerance to ocean acidification. By comparing individuals that demonstrate low sensitivity to ocean acidification and with the general population, we enhance the ability to predict how adaptation will alter the species’ response to future ocean conditions. This research will inform the fishing industry and coastal, fisheries-dependent Alaskan communities about potential effects of ocean change on commercially important species. Outcomes can be used to drive future responses and adaptations in these industries regarding affected fisheries.