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Research Area

Biological Response

Research on the biological response to ocean acidification focuses on economically, ecologically, and culturally important marine species. We can use what we know about survival, growth, and physiology to explore how aquaculture, wild fisheries, and food webs may change as ocean chemistry changes.

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What's New

See our most recent news related to biological response.


NOAA OAP’s 2023 Accomplishments

NOAA OAP selects, funds, and manages high priority, high-quality research, monitoring, and outreach activities to understand how fast the acidification is changing, and impacts these changes have on marine life, people, and economies. Check out some of the 2023 accomplishment highlights.

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NOAA ship in background during the West Coast Ocean Acidification research cruise with a mooring measuring ocean chemistry in the foreground. Credit: NOAA
OA News

NOAA declares Commitment to UN Decade OARS Programme

On behalf of NOAA, the Ocean Acidification Program submitted a Commitment to the international Ocean Acidification Research for Sustainability (OARS) Programme on December 4, 2023. OARS is a UN Ocean Decade supported program dedicated to minimizing and addressing the impacts of ocean acidification (OA) through enhanced cooperation at all levels and is aligned with Sustainable

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adaptation strategies

Join us for the Ocean Acidification Community Meeting Jan 4-6, 2023

NOAA OAP convenes community meeting in San Diego, CA!

Every three years, the NOAA Ocean Acidification Program convenes researchers, communicators and others in the OA community for a meeting to discuss and share the latest research and future needs and directions. We want your participation! Registration is free.

Meeting Goals

  • Shape the future
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Research Laboratories Studying Biological Response

NOAA national laboratories are global leaders for delivering innovative strategies for ocean observations and support tools for managing marine resources. 

NOAA’s Pacific Marine Environmental Laboratory (PMEL) makes critical observations and conducts groundbreaking research to advance our knowledge of the global ocean and its interactions with the earth, atmosphere, ecosystems, and climate. This includes research, observations, and technology development in support of society’s response to urgent challenges with ocean acidification and ocean change.  

NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) conducts world-class Earth system research, with a focus on the Atlantic Ocean region, to inform: the accurate forecasting of extreme weather and ocean phenomena, the management of marine resources, and an understanding of climate change and associated impacts. AOML improves ocean and weather services including advancing our understanding of ocean and coastal acidification and its potential impacts on coral reef and other ecosystems.

Fisheries Science Centers Studying Biological Response

NOAA National Marine Fisheries Service Science Centers have state-of-the-art experimental facilities to study the response of marine life 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. At the Pacific Islands Fisheries Science Center, coral research connects ocean conditions with reef health. 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.


Understanding the effects of ocean acidification on habitat-providing corals. 

Corals provide a critical habitat to large numbers and a diverse range of marine life. Understanding the effects of ocean acidification on coral reefs provide insight into future environmental changes.

Shallow Water Corals

Shallow water corals typically build reefs using forms of carbonate called aragonite or calcite as the building blocks for their skeletons. They occur globally in more tropical environments. Corals provide habitat to the greatest diversity of marine organisms in the world. The impacts of ocean acidification on shallow water corals are examined by the National Ocean Acidification Coral Reef Monitoring Program (NCRMP).

Deep Sea Corals
Deep sea, or cold water, corals occur along the US Pacific coast and are abundant throughout Alaska waters. While they do not form reefs in these regions, they provide habitat for many crab and fish species. Scientists at the Alaska Fisheries Science Center and partner institutions document the forms of calcium carbonate that makeup their skeletons, geographical location, and depth. These efforts assist with of assessing their vulnerability to ocean acidification.
Studying the Red Tree Coral
The red tree coral (Primnoa pacifica) is one of the most ecologically important corals in the North Pacific Ocean, ranging from Washington to the Bering Sea. These corals can be very large (up to 5 meters high and wide). They provide essential habitat for many species, include some managed fish and crabs. Thickets occur in waters that are corrosive to the calcite form of calcium carbonate, the building block for their skeletons. Alaska Fisheries Science Center researchers in Kodiak, Alaska study their physiology when exposed to current seawater and ocean acidification conditions.
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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.

China Rockfish

China rockfish (Sebastes nebulosus), which have a range extending from California to Alaska, support a popular commercial fishery. Scientists at the Northwest Fisheries Science Center examined how larval growth and survival change under elevated carbon dioxide.


Scup (Stenotomus chrysops) is a commercially and recreationally harvested fish found in coastal waters from Cape Cod, Massachusetts to Cape Hatteras, North Carolina. Scientists at NOAA’s Northeast Fisheries Science Center conducted laboratory studies to determine the effects of elevated carbon dioxide on scup growth and otolith (ear bone) development in their first year of life.

Walleye Pollock

Alaskan walleye pollock (Theragra chalcogramma) support one of the largest fisheries in the world. Walleye pollock is a groundfish in the cod family found in North Pacific temperate and subarctic waters. Researchers at the Alaska Fisheries Science Center Newport, Oregon study how early life stages of walleye pollock respond to ocean acidification conditions. They have found that walleye pollock show resilience to ocean acidification conditions by investigating egg development, larval growth and survival, and behavioral patterns and condition of juveniles. Work continues on other life stages of this important fish.


Cobia (Rachycentron canadum) is a large, pelagic fish found in most tropical and warm temperate regions around the globe. It is a top predator in marine ecosystems, and the target of high-value recreational and commercial fisheries. Scientists from the University of Miami and NOAA’s Atlantic Oceanographic and Meteorological Laboratory found that exposing larval cobia to ocean acidification conditions increased the size and density of their otoliths (ear bones). They used models to demonstrate that these changes could increase the hearing range of the larvae, altering how they perceive sounds in the world around them.

Coho Salmon

Coho salmon (Oncorhynchus kisutch), one of the six species of anadromous Pacific salmon species, is ecologically, culturally, and economically important. It spawns in streams around the northern Pacific Rim from California to Japan. Young coho salmon migrate from these streams to the sea to grow to maturity, and journey back to their natal streams to spawn the next generation. Salmon use their sense of smell to find their way back from the ocean to the stream where they hatched. Young salmon must imprint on the smell of their natal stream and also use their sense of smell avoid predators. In collaboration with Evan Gallagher’s lab at the University of Washington and using Washington Sea Grant and Washington Ocean Acidification Center funding, scientists at the Northwest Fisheries Science Center tested whether ocean acidification conditions affect the ability of juvenile coho salmon to smell and respond to scents.

Forage Fish

Forage fish are small-bodied fish that play an important role in the ecosystem, transferring energy from plankton to larger fish, including those harvested by people. Scientists at the Northeast Fisheries Science Center’s Sandy Hook laboratory study how two important forage fish from inshore East Coast waters, the mummichog (Fundulus heteroclitus) and the Atlantic silverside (Menidia menidia), may respond to ocean acidification conditions. Their studies focus on how exposure of adults to ocean acidification conditions can influence the survival and growth of their offspring. Such “transgeneration” work is vital for understanding how ocean acidification may influence populations in nature.


Summer flounder (Paralichthys dentatus) and winter flounder (Pseudopleuronectes americanus) are ecologically and economically important species in Northeast and mid-Atlantic marine and estuarine ecosystems. Scientists at NOAA’s Northeast Fisheries Science Center in Sandy Hook, New Jersey examine the effects of increased carbon dioxide on the survival and development of early life stages (eggs and larvae) of both flounder species.

Pacific Cod

Pacific cod (Gadus macrocephalus) is an important groundfish in the North Pacific and Bering Sea food webs and supports one of the nation’s largest and most valuable finfish fisheries. Researchers at the Alaska Fisheries Science Center Newport, Oregon facility conduct laboratory studies to assess how ocean acidification conditions may change the growth, survival, and behavior of larvae and juveniles. These studies are similar to research with Walleye pollock. Together, information about the biological response of these two related species will inform managers on how they may respond to ocean acidification.

Northern Rock Sole

Northern rock sole (Lepidopsetta polyxystra) is a commercially harvested flatfish in the Bering Sea and Gulf of Alaska groundfish fisheries. Harvest increased in recent years in response to the strong market for their roe. Thus, understanding the biological sensitivity to ocean acidification in roe is important both for their early survival and growth and to support this market. Alaska Fisheries Science Center researchers at the Newport, Oregon laboratory found that northern rock sole larvae were more likely to die and were in poorer condition when exposed to high carbon dioxide levels.


Sablefish (Anoplopoma fimbria), also known as black cod, is a marine groundfish that supports one of the most valuable commercial fisheries along the U. S. West Coast. Juvenile sablefish use their sense of smell to find food, and any changes in their ability could have big consequences for their survival. In collaboration with Evan Gallagher’s lab at the University of Washington and using Washington Sea Grant and Washington Ocean Acidification Center funding, scientists at the Northwest Fisheries Science Center test whether ocean acidification conditions affect the ability of juvenile sablefish juveniles to smell and respond to scents.


Shellfish such as oysters, clams, crabs, and scallops provide food for marine life and people too. Importantly, shellfish make their shells from calcium carbonate, which contains carbonate ions as building blocks. The decreases in the concentration of these building blocks in seawater with ocean acidification can directly affect building and maintaining calcium carbonate structures. This may impact their survival, growth, and physiology and the food webs and economies that depend on them.

Click on each species to see what we're monitoring

Dungeness crab (Cancer magister) support an economically and culturally important commercial fishery along the U. S. West Coast. This crab also plays important roles in pelagic food webs in their early life-stages and benthic food webs as juveniles and adults. Scientists at the Northwest Fisheries Science Center and collaborators from the Suquamish Tribe studied the survival, development, and growth during its egg, zooplankton, and early benthic stages. Researchers found that more acidified seawater slows embryonic and early larval development and causes larval mortality. Future studies will include measurements of behavior, metabolism, and gene expression.

The geoduck (pronounced gooey-duck; Panopea generosa) is a long-lived, massive, burrowing clam native to coastal waters of the Northwest Pacific. Clammers harvest geoducks in the wild and are also grown in aquaculture. In Washington State’s Puget Sound, the wild geoduck fishery, enacted primarily by tribal fisheries, worth $32 million annually, and geoduck aquaculture has recently experienced significant growth. Because of the species’ economic and cultural importance, scientists at the Northwest Fisheries Science Center are studying larval geoducks in different carbon dioxide environments, looking at their survival, development, and genetics. The genetics research explores whether the species has the potential to adapt to ocean acidification. 

Many species of king crab live within Alaskan waters, including red king crab (Paralithodes camtschaticus), golden king crab (Lithodes aequispinus), Tanner crab (Chionoecetes bairdi), and snow crab (Chionoecetes opilio). All four species support important commercial fisheries in Alaska. Scientists at the Alaska Fisheries Science Center conduct experiments investigating how embryos, larvae, and juveniles of these species develop and grow under high carbon dioxide conditions and how it alters their physiology. Researchers use these data and bioeconomic models to explore how ocean acidification may affect the economics of Alaska’s crab fisheries. Data from the experiments also provide information on how different ecotypes of king crab will respond to changes in ocean chemistry.

Atlantic surf clams (Spisula solidissima) occur in eastern North Atlantic waters and are commercially fished off the coasts of Massachusetts, New Jersey, Delaware, Maryland, and Virginia. Researchers at the Northeast Fisheries Science Center, in collaboration with scientists at Woods Hole Oceanographic Institution, conducted experiments investigating the effects of ocean acidification on the development of early life stages of surf clams, and are exploring how food availability and temperature influence their development.

Sea scallops (Placopecten magellanicus) support a highly valuable commercial fishery in the U.S. northeast. Scientists at NOAA’s Northeast Fisheries Science Center and Wood’s Hole Oceanographic Institution conduct laboratory experiments examining the interactive effects of carbon dioxide and other potential stressors on larval growth and shell formation. They found that warming temperatures and ocean acidification hinders growth. Read more 

See our funded projects in biological response. 
Use the Projects Portal to search. 

Dungeness crab in a crab hold. Credit: Austin Trigg, NMFS

Understanding CO2 effects on Dungeness crab: population variability, temperature interactions, calcification process, and carbonate sensitivity Why we care​Dungeness crabs support the most valuable fishery on the U.S. West Coast. Previous..

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..
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..


Plankton are tiny plants and animals that many marine organisms, 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 ocean’s acidity increases. Decreases in these building blocks 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.

Copepods, Illustrated in 1892 by Wilhelm Giesbrecht
Copepods are crustacean zooplankton that are important prey species in many marine food webs. Scientists at the Northwest Fisheries Science Center collaborated with the University of Washington to study how ocean acidification affects survival and development of early life stages of the copepod Calanus pacificus. The research team conducted detailed field studies to describe the carbonate chemistry environment where different life stages of copepod live in Puget Sound’s Hood Canal. This project is partially funded by Washington Sea Grant.
Krill are crustacean zooplankton that are important prey species in many marine food webs. Scientists at the Northwest Fisheries Science Center collaborated with the University of Washington to study how ocean acidification affects survival and development of early life stages of the krill Euphasia pacifica. The work also describes the carbonate chemistry where different life stages of krill species live in Puget Sound’s Hood Canal. The research team found that ocean acidification did not affect egg hatch, but lower pH slowed larval development was decreased survival within Puget Sound. Results suggest that this krill species may live near the limits of its pH tolerance in Puget Sound. This project was funded by Washington Sea Grant.
Pteropods are small snails that live as zooplankton in the water column, using their foot as wings to “fly” through the sea. They are an important prey species for many fish and marine mammals in high latitude ecosystems, including salmon and other fish, seabirds, and whales. Scientists at the Pacific Marine Environmental Laboratory and Northwest Fisheries Science Center documented the biological sensitivity of pteropod shells to ocean acidification. These researchers collected pteropods with partially dissolved shells from high carbon dioxide locations along the U.S. West Coast and confirmed the sensitivity of North Pacific pteropods to these conditions in the laboratory.
Phytoplankton are the diverse set of photosynthetic organisms that are the foundation of marine food webs. As a whole, marine phytoplankton produce over half of the oxygen in our atmosphere. Scientists are interested in how the species composition and nutritional content of phytoplankton may change with ocean acidification, as both will affect entire food webs, from clams to fish and whales.
Researchers at the Northeast Fisheries Science Center have performed experiments on a number of phytoplankton species under different CO2 and pH regimes to understand their sensitivity, including how their nutritional content will change. Some of these experiments focus on single species in isolation (Thalassiosira weissflogii, Thalassiosira pseudonana, Pseudo-nitzschia delicatissima, Dunaliella salina, Chlorella autotrophica, Isochrysis sp., Tetraselmis sp.) and others on communities of species collected from the coastal environment. Research to date has found that the species studied vary in their response to high carbon dioxide conditions: some increase growth rate, others decrease it, and others are insensitive; some change their elemental composition and others don’t. Data from this work demonstrate that changes in ocean carbon chemistry can have large effects on ocean phytoplankton, with potentially large feedbacks to ecosystems and ocean biogeochemical cycles.
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Related Publications

See publications from our funded projects for biological response

Citation: Tobias Schwoerer, Kevin Berry, Darcy G. Dugan, David C. Finnoff, Molly Mayo, Jan Ohlberger, Eric J. Ward, Fish or not fish—fisheries participation and harvest diversification under economic and ecological change, Marine Policy, Volume 157, 2023, 105833, ISSN 0308-597X,
Citation: Barkley HC, Oliver TA, Halperin AA, Pomeroy NV, Smith JN, Weible RM, Young CW, Couch CS, Brainard RE and Samson JC (2022) Coral reef carbonate accretion rates track stable gradients in seawater carbonate chemistry across the U.S. Pacific Islands. Front. Mar. Sci. 9:991685. doi: 10.3389/fmars.2022.991685
Citation: Knor, L. A. C. M., Sabine, C. L., Sutton, A. J., White, A. E., Potemra, J., & Weller, R. A. (2023). Quantifying net community production and calcification at station ALOHA near Hawai’i: Insights and limitations from a dual tracer carbon budget approach. Global Biogeochemical Cycles, 37, e2022GB007672.

Get involved with ocean acidification

The NOAA Ocean Acidification Program exists to meet the ocean acidification research and monitoring needs of the U.S. See how you can get involved to serve your community and participate in cutting-edge research and education and outreach. 

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The NOAA Ocean Acidification Program (OAP) works to prepare society to adapt to the consequences of ocean acidification and conserve marine ecosystems as acidification occurs. Learn more about the human connections and adaptation strategies from these efforts.

Adaptation approaches fostered by the OAP include:


Using models and research to understand the sensitivity of organisms and ecosystems to ocean acidification to make predictions about the future, allowing communities and industries to prepare


Using these models and predictions as tools to facilitate management strategies that will protect marine resources and communities from future changes


Developing innovative tools to help monitor ocean acidification and mitigate changing ocean chemistry locally


On the Road

Drive fuel-efficient vehicles or choose public transportation. Choose your bike or walk! Don't sit idle for more than 30 seconds. Keep your tires properly inflated.

With your Food Choices

Eat local- this helps cut down on production and transport! Reduce your meat and dairy. Compost to avoid food waste ending up in the landfill

With your Food Choices

Make energy-efficient choices for your appliances and lighting. Heat and cool efficiently! Change your air filters and program your thermostat, seal and insulate your home, and support clean energy sources

By Reducing Coastal Acidification

Reduce your use of fertilizers, Improve sewage treatment and run off, and Protect and restore coastal habitats

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You've taken the first step to learn more about ocean acidification - why not spread this knowledge to your community?

Every community has their unique culture, economy and ecology and what’s at stake from ocean acidification may be different depending on where you live.  As a community member, you can take a larger role in educating the public about ocean acidification. Creating awareness is the first step to taking action.  As communities gain traction, neighboring regions that share marine resources can build larger coalitions to address ocean acidification.  Here are some ideas to get started:

  1. Work with informal educators, such as aquarium outreach programs and local non-profits, to teach the public about ocean acidification. Visit our Education & Outreach page to find the newest tools!
  2. Participate in habitat restoration efforts to restore habitats that help mitigate the effects of coastal acidification
  3. Facilitate conversations with local businesses that might be affected by ocean acidification, building a plan for the future.
  4. Partner with local community efforts to mitigate the driver behind ocean acidification  – excess CO2 – such as community supported agriculture, bike & car shares and other public transportation options.
  5. Contact your regional Coastal Acidification Network (CAN) to learn how OA is affecting your region and more ideas about how you can get involved in your community
       More for Taking Community Action