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.
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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.
The U.S. Northeast Shelf Large Marine Ecosystem, supports some of the nation’s most economically valuable coastal fisheries, yet most of this revenue comes from shellfish that are sensitive to ocean acidification (OA). Furthermore, the weakly buffered northern region of this area is expected to have greater susceptibility to OA. Existing OA observations in the NES do not sample at the time, space, and depth scales needed to capture the physical, biological, and chemical processes occurring in this dynamic coastal shelf region. Specific to inorganic carbon and OA, the data available in the region has not been leveraged to conduct a comprehensive regional-scale analysis that would increase the ability to understand and model seasonal-scale, spatial-scale, and subsurface carbonate chemistry dynamics, variability, and drivers in the NES. This project optimizes the NES OA observation network encompassing the Mid-Atlantic and Gulf of Maine regions by adding seasonal deployments of underwater gliders equipped with transformative, newly developed and tested deep ISFET-based pH sensors and additional sensors (measuring temperature, salinity for total alkalinity and aragonite saturation [ΩArag] estimation, oxygen, and chlorophyll), optimizing existing regional sampling to enhance carbonate chemistry measurements in several key locations, and compiling and integrating existing OA assets. The researchers will apply these data to an existing NES ocean ecosystem/biogeochemical (BGC) model that resolves carbonate chemistry and its variability.
Over the past 15 years, waters in the Gulf of Maine have taken up CO2at a rate significantly slower than that observed in the open oceans due to a combination of the extreme warming experienced in the region and an increased presence of well-buffered Gulf Stream water. The reduced uptake of CO2 by the shelves could also alter local acidification rate, which differ from the global rates. The intrusion of anthropogenic CO2is not the only mechanism that can reduce Ωarag within coastal surface waters. Local processes like freshwater delivery, eutrophication, water column metabolism, and sediment interactions that drive variability on regional scales can also modify spatial variability in Ωarag. Global projections cannot resolve these local processes with resolution of a degree or more. Some high-resolution global projections have been developed which perform well in some coastal settings . However, these simulations do not include regional biogeochemical processes described above which can amplify or dampen these global changes, particularly in coastal shelf regions. Our hypothesis is that a regionally downscaled projection for the east coast of the US can be used to evaluate the ability of the existing observational network to detect changes in ocean acidification relevant stressors for scallops and propose a process-based strategy for the network moving forward.
This project will expand the quantity and quality of ocean acidification (OA) monitoring across Northeastern U.S. coastal waters. The new OA data and incorporation of the world’s first commercial total alkalinity (TA) sensor into our regional observing system (NERACOOS) are designed to supply needed baseline information in support of a healthy and sustainable shellfish industry, and to aid in assessments and projections for wild fisheries. In working with partners to develop this proposal, clear concerns were brought forward regarding the potential impacts of increasing ocean acidity that extend from nearshore hatcheries and aquaculture to broader Gulf of Maine finfish and shellfish industries and their management. Stakeholder input and needs shaped the project scope such that both nearshore and offshore users will be served by TA sensor deployments on partner platforms, including time series data collection at an oyster aquaculture site, on the NOAA Ship of Opportunity AX-2 line, and on federal and State of Maine regional fish trawl surveys. In all, five different deployment platforms will be used to enhance ocean acidification monitoring within the Northeast Coastal Acidification Network (NE-CAN) with significant improvement in temporal and spatial coverage.
Adding the all-new TA measurement capability to the regional observation network will provide more accurate, certain, and reliable OA monitoring, and an important project objective is to demonstrate and relay this information to regional partners. Data products to be developed from the multi-year measurements include nearshore and offshore baseline OA seasonal time series as well as threshold indices tied to acidification impacts on larval production at the Mook Sea Farm oyster hatchery. An outreach and technical supervision component will include the transfer of carbonate system observing technologies to our partners and to the broader fishing industry, resource management, and science communities. NERACOOS will provide data management and communication (DMAC) services and work towards implementing these technological advances into the IOOS network.
Working across four IOOS Regional Associations in partnership with the shellfish industry and other groups affected by ocean acidification (OA), our proposal is divided into four tasks that continue the foundational aspects established to date and expand both technical capacity and the development of new technology with respect to OA observing needs for shellfish growers and other related impacted and potentially vulnerable U.S. industries, governments (tribal, state, local) and other stakeholders. Our proposed work includes development of observing technology, expert oversight intelligence, data dissemination, and outreach and will be executed by a team that includes a sensor technology industry and academic and government scientists. We will: 1) Develop new lower cost and higher accuracy sensor technology for OA monitoring and expand them to new sites; 2) Utilize regional partnerships of users and local experts to implement and provide Quality Assurance/Quality Control (QA/QC) tests of the new OA sensors; 3) Establish data handling and dissemination mechanisms that provide both user-friendly and standards-based web service access that are exportable from the Pacific Coast module to the entirety of U.S. Integrated Ocean Observing System (IOOS); and 4) Provide education and outreach services to stakeholders concerned about and potentially impacted by OA.