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.

Buoys & Moorings

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


Ship surveys

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

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).

Wave Gliders

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.




Interactions between ocean acidification and metal contaminant uptake by Blue Mussels

Interactions between ocean acidification and metal contaminant uptake by Blue Mussels

David Whitall - NOAA National Centers for Coastal Ocean Science

Assessing ocean acidification as a driver for enhanced metals uptake by Blue mussels (Mytilus edulis): implications for aquaculture and seafood safety

Why we care
Ocean acidification causes changes in the chemistry of stressors such as metals and may affect both the susceptibility of these animals to the contaminants as well as the toxicity. This is especially important for animals like blue mussels and other economically important shellfish that accumulate toxins in their bodies. Metal accumulation as a co-stressor of ocean acidification is not well documented for northeastern U.S. shellfish aquaculture species and better understanding these relationships supports seafood safety. 

What we are doing
This work investigates the impacts of metal speciation (forms) on blue mussels under acidified conditions in both field and laboratory experiments. Scientists will first study uptake rates of these metals by blue mussels and then see how changing conditions affects their accumulation and toxicity. Comparing what they learn in the lab to what occurs in the field where these mussels are farmed, helps support decisions for seafood safety and industry best practices.

Benefits of our work
Coastal managers and aquaculturists can use these results that provide the societal benefits of better informed siting of aquaculture and safer seafood.

Wednesday, August 31, 2022

Vulnerability of oyster aquaculture and restoration to ocean acidification and other co-stressors in the Chesapeake Bay

Marjy Friedrichs (Virginia Institute of Marine Science ), Emily Rivest (Virginia Institute of Marine Science ), David Wrathall (Oregon State University)

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.

Monday, December 21, 2020

Understanding the vulnerability of shellfish hatcheries in the Chesapeake Bay to acidification


Acidification in brackish estuarine environments, such as the Chesapeake Bay, is intensified by coastal inputs such as runoff, atmospheric pollution and freshwater sources. The Chesapeake Bay is home to commercial shellfish hatcheries that supply seed that is sold to and planted in hundreds of shellfish farms within the Chesapeake. A great deal of research has been dedicated to understanding the impact of acidification on shellfish, and has shown even greater impacts to shellfish growth and survival in lower salinity and nutrient-rich environments. The shellfish industry relies on consistent hatchery production to sustain and expand operations that could greatly benefit from regional OA forecasts and metrics. This project will synthesize recent CO2 system observations with long-term water quality parameters and combine observations an existing baywide, high-resolution 3D model. The proposed research will develop forecasts of acidification and develop acidification metrics tailored to support decision-making needs of commercial shellfish hatchery and nursery operators.

Wednesday, April 15, 2020

How sensitive are systems in the Chesapeake Bay to acidification and nutrient pollution?

Jeremy Testa, University of Maryland

The wild oyster industry has suffered repeated collapses in the Chesapeake Bay due to overharvesting, disease, and declining environmental conditions. How future conditions will affect the Eastern oyster remain uncertain, not only because these conditions such as increased freshwater are difficult to predict , but also because the interactions between stressors such as ocean acidification, temperature, nutrient runoff and sea level rise could lead to unexpected chemical, biological, and economic change. The changes in stressors and their impacts do not always proceed in a straight line.The potential responses of various life stages of the Eastern oyster to stressors like acidification and eutrophication has received little attention. This project will study the impact of different stressors to Chesapeake Bay, a large estuarine system, and the Eastern oyster. The study will bring together different models to understand the relationship between biogeochemical cycling of carbon, oxygen, and nutrients, oyster growth and survival, and oyster economic profitability in the Chesapeake Bay ecosystem. The project will provide insights into future conditions and habitats where aquaculture and wild oyster populations may be most vulnerable to the climate and ocean changes.
Tuesday, October 2, 2018

Can meadows of underwater eelgrass help mitigate the harmful effects of Ocean Acidification on Eastern oysters?

Emily Rivest, Virginia Institute of Marine Science

Submerged Aquatic Vegetation (SAV), such as eelgrass, could mitigate the harmful impacts of ocean acidification on Eastern oysters by reducing the acidity of waters where oysters grow. These underwater grasses take up carbon dioxide and release oxygen into coastal waters, reducing the exposure of marine organisms to increases in acidity conditions that slow or stop oyster growth and reproduction. Oysters, in turn, improve water clarity forseagrasses to thrive by filtering particles out of the water and allowing more sunlight to penetrate. This modeling project will identify the threshold of acidification beyond which the economically important Eastern oyster is negatively impacted and will evaluate the potential benefit of seagrasses in protecting oysters and the ecosystem services they provide. The modeling tool will also identify the acidification conditions in which seagrass restoration is most helpful and when the economic benefits of this restoration to Easter oyster production outweigh the costs. At the end of this project, the final model will be freely available as an online tool and will help scientists, managers and oyster growers assess the potential for both seagrass and oyster restoration.
Tuesday, October 2, 2018