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.
PMEL Sustained Ocean Acidification Biogeochemical and Ecological Survey Observations
Why we care
U.S. West coast-wide hydrographic surveys have been conducted intermittently from 2007 to 2017, providing evidence for the geographic extent and severity of ocean acidification in the continental shelf ecosystem. Scientists on the NOAA West Coast Ocean Acidification (WCOA) discovered that the combined effects of anthropogenic and biologically-derived carbon dioxide resulted in significant biological impacts for oyster larvae and pteropods, which are small, ecologically important mollusks for the food web.
What we are doing
This project executes a large-scale survey of ocean acidification carbonate chemistry in the California Current System and continues processing data and publishing scientific papers based on 2016 and 2017 surveys findings. This survey determines the spatial distributions of temperature, salinity, pH, dissolved inorganic carbon, total alkalinity, oxygen, nutrients, and biological parameters along the west coast of North America. Survey results will provide the basis for accurate assessments of changing ocean chemistry in the following areas: 1) spatial variability; 2) extent and causes of long-term changes in carbonate system parameters and their impacts on calcifying (shell-building) organisms; and 3) empirical relationships for obtaining high-resolution information on ocean acidification collected on moorings.
Benefits of our work
This project links the combined stressors of increased temperature, acidification, and hypoxia (low oxygen) with effects on marine organisms in the region and identifies spatial variability of acidifying conditions during the spring/summer upwelling season. In addition to scientific partners, this project engages a NOAA Teacher At Sea (TAS) fellow on the cruise to help develop outreach and education on West Coast ocean acidification.
Coastal acidification and its associated co-stressors present a serious and credible threat to the success of both oyster aquaculture and restoration in the Chesapeake Bay. Recent research provides a clearer understanding of the physiological sensitivity of different economically and culturally valuable shellfish species to ocean acidification (OA), but we still lack a basic understanding of how vulnerability differs across the range of shellfish-reliant stakeholders, specifically participants in oyster aquaculture, the growers, watermen and coastal restoration managers. This basic knowledge gap motivates this work, which aims to: (1) assess the vulnerability of the oyster aquaculture industry and oyster restoration to OA and other co-stressors, and (2) produce the information required by regional communities to aid in adaptation to these stressors. In achieving these goals, we will better understand which shellfish stakeholders will be able to successfully adapt, which will seek alternative livelihoods, and what specifically causes the difference between these two disparate outcomes.
The ocean is changing faster than it has in the last 66 million years. Now, Oregon oysters are being farmed in Hawaii. That fix won’t work forever.
A little more than ten years ago, a mysterious epidemic wiped out baby oyster populations. After two years of massive losses and no answers, scientists testing the waters discovered what was really wrong: the ocean water flowing into the hatcheries had changed, and the oysters weren’t able to build their shells.
Check out the full [EasyDNNnewsLink|77] by H. Claire Brown, The New Food Economy, 28 November 2017.
A small but growing number of entrepreneurs are creating sea-farming operations that cultivate shellfish together with kelp and seaweed, a combination they contend can restore ecosystems and mitigate the impacts of ocean acidification.
For Bill Mook, coastal acidification is one thing his oyster hatchery cannot afford to ignore.
Mook Sea Farm depends on seawater from the Gulf of Maine pumped into a Quonset hut-style building where tiny oysters are grown in tanks. Mook sells these tiny oysters to other oyster farmers or transfers them to his oyster farm on the Damariscotta River where they grow large enough to sell to restaurants and markets on the East Coast.