Biological Response

NOAA's Ocean Acidification Program supports research that focuses on economically and ecologically important marine species. Research of survival, growth, and physiology of marine organisms can be used to explore how aquaculture, wild fisheries, and food webs may change as ocean chemistry changes.


A number of NOAA National Marine Fisheries Service Science Centers have state-of-the-art experimental facilities to study the response of marine organisms to the chemistry conditions expected with ocean acidification.

The Northeast Fisheries Science Center has facilities at its Sandy Hook, NJ and Milford, CT laboratories; the Alaska Fisheries Science Centers at its Newport, OR and Kodiak, AK laboratories; and the Northwest Fisheries Science Center at its Mukilteo and Manchester, WA laboratories. All facilities can tightly control carbon dioxide and temperature. The Northwest Fisheries Science Center can also control oxygen, and can create variable treatment conditions for carbon dioxide, temperature, and oxygen. These facilities include equipment for seawater carbon chemistry analysis, and all use standard operating procedures for analyzing carbonate chemistry to identify the treatment conditions used in experiments.



Both deep sea and shallow reef-building corals have calcium carbonate skeletons.  As our oceans become more acidic, carbonate ions, which are an important part of calcium carbonate structures, such as these coral skeletons, become relatively less abundant. Decreases in seawater carbonate ion concentration can make building and maintaining calcium carbonate structures difficult for calcifying marine organisms such as coral.



Increased levels of carbon dioxide in our ocean can have a wide variety of impacts on fish, including altering behavior, otolith (a fish's ear bone) formation, and young fish's growth. Find out more about what scientists are learning about ocean acidification impacts on fish like rockfish, scup, summer flounder, and walleye pollock.


Shellfish, such as oyster, clams, crabs and scallop, provide food for marine life and for people, too. Shellfish make their shells or carapaces from calcium carbonate, which contains carbonate ion as a building block. The decreases in seawater carbonate ion concentration expected with ocean acidification can make building and maintaining calcium carbonate structures difficult for calcifying marine organisms like shellfish. This may impact their survival, growth, and physiology, and, thus, the food webs and economies that depend on them.


Plankton are tiny plants and animals that many marine organisms, ranging from salmon to whales, rely on for nutrition. Some plankton have calcium carbonate structures, which are built from carbonate ions. Carbonate ions become relatively less abundant as the oceans become more acidic. Decreases in seawater carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying marine organisms such as plankton. Changes to the survival, growth, and physiology of plankton can have impacts throughout the food web.


Assess, anticipate, adapt: Vulnerability and Responses to Ocean Acidification

Assess, anticipate, adapt: Vulnerability and Responses to Ocean Acidification

NOAA Ocean Acidification Program

There are areas in the United States where marine resources and the communities and industries that depend on them are particularly vulnerable to the impacts of ocean acidification. In three US regions, our understanding of vulnerability is being advanced by coupling ocean and social science data to equip communities and industries with the information needed to evaluate, anticipate, and adapt to ocean acidification.
Thursday, March 15, 2018

Mid-Atlantic Ocean Acidification Graduate Fellowship Opportunity

Ocean Acidification Program and Sea Grant

The Mid-Atlantic Sea Grant Programs in partnership with the NOAA Ocean Acidification Program, are pleased to announce the availability of Ocean Acidification Graduate Research Fellowships for a two-year period covering the 2018 and 2019 academic years. The fellowship is open to full-time graduate students at any academic institution in Delaware, Maryland, New Jersey, New York and Virginia who are engaged in coastal and marine research relevant to regional ocean, coastal, and estuarine acidification. The focus should be on improving understanding of the potential ecological consequences of increasing carbon dioxide concentration in regional coastal waters. Projects may encompass natural and/or social science research topics.

Proposals are being accepted through 5:00 pm ET on Friday, April 13, 2018 via eSeaGrant.  

This announcement and additional information can be found on each state Sea Grant program’s website.

Monday, March 5, 2018
Why I put a pteropod in a CT scanner to study the impacts of ocean acidification

Why I put a pteropod in a CT scanner to study the impacts of ocean acidification

Tuesday, March 13th, 3pm EDT (12pm PDT)

During this webinar Rosie Oakes of the National Academy of Sciences of Drexel University will discuss how she used a micro CT scanner to image pteropods in 3D to measure their shell thickness and volume. She will explain how she enlarges these 3D reconstructions to print them for educational purposes, and how you can do the same. Finally, she'll share her new research direction, using museum collections of pteropods to decipher how they have been affected by ocean acidification since the industrial revolution.

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Wednesday, February 28, 2018

Low pH in Coastal Waters of the Gulf of Maine: A Data Synthesis-Driven Investigation of Probable Sources, Patterns and Processes Involved

David W. Townsend, University of Maine

Coastal Maine supports valuable lobster, clam, oyster and other shellfish industries that comprise >90% of Maine’s record $616M landed value last year. Earlier monitoring efforts in Maine and New Hampshire have documented periods of unusually acidic conditions in subsurface waters of Maine’s estuaries, which may be driven by episodic influxes of waters from the Gulf’s nutrient-rich, highly productive coastal current system. Sources of acidity to the estuaries also include the atmosphere, freshwater fluxes, and local eutrophication processes, all modulated by variability imparted by a number of processes.This project is a data synthesis effort to look at long-term trends in water quality data to identify the key drivers of acidification in this area. Extensive data sets dating back to the 1980s (including carbonate system, hydrography, oxygen, nutrients, and other environmental variables) will be assembled, subjected to QA/QC, and analyzed to assess acidification events in the context of landward, seaward and direct atmospheric sources, as may be related to processes operating on tidal to decadal timescales. Such analyses are requisite for any future vulnerability assessments of fishery-dependent communities in Maine and New Hampshire to the effects of coastal acidification.

Friday, December 22, 2017

Vulnerability and Adaptation to Ocean Acidification Among Pacific Northwest Mussel and Oyster Stakeholders

David J. Wrathall, George Waldbusser, and David Kling, Oregon State University

Ocean acidification (OA) is already harming shellfish species in the Pacific Northwest, a global hotspot of OA. While OA poses a threat to regional communities, economies, and cultures that rely on shellfish, identified gaps remain in adaptive capacity and vulnerability of several stakeholders. This project will address these gaps by extending long-standing collaborative OA vulnerability research with shellfish growers to include other shellfish users (e.g. port towns, Native American tribes and shellfish sector employees). The project includes five objectives: 1) Map variations in shellfisheries’ exposure to OA and identify those that are most sensitive, 2) quantify production losses from OA and costs of investment in adaptation 3) Identify potential pathways for adaptation, 4) identify key technological, institutional, legislative, financial and cultural barriers to OA adaptation, 5) evaluate the cost of potential adaptation strategies, and develop behavioral models to predict the likelihood of users adopting specific adaptation strategies. The research is designed to identify key vulnerabilities, determine the cost of OA to Pacific Northwest shellfish stakeholders, and to model adaptation pathways for maximizing resilience to OA. The adaptation framework developed here will be replicable in other shellfisheries yet to experience OA impacts.


Friday, December 22, 2017