NOAA’S ROLE IN OCEAN 

ACIDIFICATION MONITORING 

AND RESEARCH

Freshly harvested oysters from Yaquina Bay, Oregon (Photo credit: NOAA) 

Front cover: Octocorallia: Alcyonacea, the “mushroom coral” has stinging cells or nematocysts within its tentacles that are used to capture minute 

prey. (Photo credit: NOAA/OER)

The National Oceanic and Atmospheric Administration (NOAA) has the 

operational responsibility to protect and preserve ocean, coastal, and Great 

Lakes resources and to provide critical and accurate weather, climate, and 

ecosystem forecasts that support national safety and commerce. The Federal 

Ocean Acidification Research and Monitoring (FOARAM) Act of 2009 mandates 

that NOAA have an active monitoring and research program to determine 

potential impacts of decreased ocean pH and carbonate saturation states.
OCEAN ACIDIFICATIONis the ongoing decrease 

in the pH of the Earth’s ocean, caused by its uptake of carbon dioxide from 

the atmosphere. pH is a measure of ocean acidity. In addition to other 

impacts of global climate change, ocean acidification poses potentially 

serious threats to the health of the world’s ocean and its ecosystems. 

We need ocean ecosystems for the oxygen we breathe, the seafood we 

eat, the beaches we enjoy, and many other services they provide. Today, 

more than a billion people worldwide rely on food from the ocean as 

their primary source of protein. Many jobs and economies in the U.S. 

and around the world depend on the fish and shellfish in our ocean.

Scientists are rapidly expanding what we know about ocean 

acidification, but the science of ocean acidification is still in its infancy. 

Sustained efforts to monitor ocean acidification worldwide are only 

beginning, and the impacts of ocean acidification at local and regional levels 

are not well understood. With the pace of ocean acidification accelerating, 

scientists, resource managers, and policymakers recognize the urgent need 

to strengthen the science as a basis for sound decision making and action. 

This graph shows the correlation 

between rising levels of carbon 

dioxide (CO2) in the atmosphere 

shown in violet, with rising CO2 levels 

in the ocean, shown in bright blue. As 

more CO2 accumulates in the ocean, 

the pH of the ocean decreases, 

shown in pale aqua. (Modified after 

R.A. Feely, Bulletin of the American 

Meteorological Society, July 2008)

•••••••

•••••••

The overarching goal of the NOAA Ocean and Great Lakes Acidification Research Plan

is to predict how ecosystems will respond to acidification and to provide information 

that resource managers can use to address acidification issues. This document is 

a synopsis of the NOAA Ocean and Great Lakes Acidification Research Plan.

NOAA Ocean and Great Lakes Acidification Research Plan | 3
The pteropod, or “sea butterfly”, is 

a tiny sea creature about the size 

of a small pea. Pteropods are a 

major food source for many species 

of fish. The photos below show 

what happens to a pteropod’s shell 

when placed in sea water with pH 

and carbonate levels projected 

for the year 2100. The shell slowly 

dissolves after 45 days. (Photo 

credit: R. Hopcroft, University of 

Alaska Fairbanks)

From the 18th century 

until today, ocean 

pH decreased by 0.1 

pH units. By the year 

2100, scientists project 

that ocean pH will 

drop an additional 

0.1-0.3 units from the 

current pH of 8.1- up 

to a 150% increase 

in acidity relative to 

the beginning of the 

industrial era. A pH 

unit is a measure of 

acidity ranging from 

0-14. The lower the 

value, the more acidic 

the measurement. 

Becoming more acidic is 

a relative shift in pH to 

a lower value. Even this 

seemingly small change 

in pH toward increased 

acidity is significant 

to a living organism.

Photo credit: Used with 

permission, National 

Geographic Images

THE CASE FOR 

OCEAN ACIDIFICATION 

MONITORING 

AND RESEARCH

Since the beginning of the Industrial 

Revolution in the mid-18th century, atmospheric 

levels of carbon dioxide, or CO2, rose from 280 to 

390 parts per million. About 50 percent of the 

increase occurred over the last 30 years. Nearly 

one-third of the CO2 released into the atmosphere 

every year is absorbed by the ocean. This means 

that as atmospheric CO2 levels go up, CO2 levels in 

the ocean also increase. This increase translates 

to a shift in the chemical balance in ocean water, 

lowering the pH of the ocean and reducing the 

availability of carbonate ions. This effect, known as 

ocean acidification, has implications for the ocean 

and, ultimately, what we depend on from it.

Ocean acidification is expected to impact 

ocean species to varying degrees. A more acidic 

environment has a dramatic effect on some 

calcifying species, or species that build calcium 

carbonate shells, such as oysters. The panel of 

photographs on the left shows what happens to a 

pteropod, a shelled free-swimming marine snail, 

when it is exposed to ocean water adjusted to sea 

water chemistry projected for the year 2100. Its 

shell dissolves after approximately 45 days in this 

environment. This is one of several direct effects of 

ocean acidification described on the opposite page.

4 | September 2010

0 days

15 days

30 days

45 days
Reduced calcification rate of shell-forming 

animals – The reduced saturation state affects 

the ability to produce a calcium carbonate 

shell. This, in turn, could lead to dissolution 

of existing calcium carbonate structures.

Altered reproduction and survival at lower pH

– Organisms generally require energy to maintain 

appropriate intracellular pH balance. Altering the 

external pH of seawater can overwhelm pH control 

mechanisms, affecting reproduction or survival.

Reduced olfaction in fish – Increased CO2

in seawater can affect the ability of fish to 

detect critical olfactory, or sensory, cues.

Increased photosynthesis – Because CO2 is 

required for photosynthesis, some photosynthetic 

organisms, especially those without effective carbon 

concentrating mechanisms, may have increased 

photosynthetic rates with increased CO2.

Hypercapnia – Increased CO2 in internal fluids, 

especially in highly energetic species like squid, 

can affect mobility, survival or reproduction. 

The ability of organisms to decrease CO2 

concentrations in internal fluids by transferring 

CO2 across membranes to seawater is reduced 

when seawater CO2 concentrations are high.

Acoustic disruption from reduced sound 

absorption – Changes in ocean pH will alter the 

acoustic properties of the ocean, increasing 

transmission of low frequency sounds, which may 

affect species relying on acoustic information.

Changes in speciation of some metals, 

nutrients, or toxic compounds – Acidification 

will alter speciation (ionic form) of various 

metals, nutrients, or toxins in a way that may 

affect species reproduction and survival.

When shelled organisms are at risk, the entire 

food web also is at risk. For example, pteropods are 

an important food source for salmon. According 

to some research reports, a 10 percent drop in 

pteropod production could result in a 20 percent 

drop in the mature body weight of pink salmon. 

Other species that may be affected by 

ocean acidification include oysters, clams, sea 

urchins, shallow water and deep-sea corals, the 

calcium carbonate-shelled organisms known as 

formanifera, and some fish species. Organisms 

potentially vulnerable to ocean acidification will 

be studied under the NOAA research program.

Selected Legislative Drivers

POTENTIAL 

DIRECT EFFECTS OF 

OCEAN ACIDIFICATION

Federal Ocean 

Acidification Research 

and Monitoring 

Act (FOARAM)

MagnusonStevens Fisheries 

Conservation Act

Coastal Zone 

Management Act

Coastal Monitoring Act

Marine Mammal 

Protection Act

National Marine 

Sanctuaries Act

Endangered Species Act

Coral Reef 

Conservation Act

Clean Water Act

Harmful Algal Bloom 

and Hypoxia Research 

and Control Act

NOAA Ocean and Great Lakes Acidification Research Plan | 5

Chinook salmon (Photo credit: NOAA)
STRATEGIC

SCIENCEBASED

GUIDANCE

A set of core hypotheses are intended to provide 

strategic science-based guidance to the NOAA research 

community and to help integrate the broad range of proposed 

activities toward a common purpose. These hypotheses focus 

on characterizing biogeochemical changes across a range of 

environments, evaluating responses of key aquatic organisms 

and ecosystems, and illuminating the range of vulnerabilities, 

all of which inform adaptive management strategies.

The themes outlined above are designed to achieve 

specific outcomes, while addressing the three hypotheses. 

New methodologies and approaches will be integrated as 

they become available. A coordinated, multidisciplinary 

program of field observations, laboratory studies, and 

modeling is critical to achieving a successful research 

strategy for ocean acidification. Such a program will 

improve our ability to predict present and project future 

responses of marine and Great Lakes biota, ecosystem 

processes, and biogeochemistry to acidification.

Themes

1. Monitor

Develop the monitoring capacity to quantify 

and track ocean acidification and its impacts in 

open-ocean, coastal, and Great Lakes systems

2. Assess

Assess the response of organisms to 

ocean and lake acidification

3. Forecast

Forecast biogeochemical and ecological 

responses to acidification

4. Manage

Develop management strategies 

for responding and adapting to 

consequences of ocean acidification

5. Synthesize

Provide a synthesis of ocean and Great 

Lakes acidification data and information

6. Engage

Provide an engagement strategy for 

education and public outreach

Rates and 

magnitudes of 

ocean acidification 

will vary.

Ocean acidification 

will change 

ecosystem 

structure, function, 

and biodiversity.

Species-specific

vulnerabilities will

differ at regional

and local scales.

Hypotheses

6 | September 2010
Repeat hydrographic surveys and time series 

measurements largely drive our current understanding of 

long-term changes in the ocean’s carbon system. Despite 

the central importance of these measurements, coordinated 

observing networks in U.S. coastal and estuarine waters 

do not exist. Consequently, these environments are 

grossly under-sampled. Enhancing and expanding the 

global moored time series network with new carbon and 

pH sensors will greatly improve that understanding. 

Temporal and spatial trends will be monitored 

through ship-based and moored observations of key 

physical, chemical, and biological parameters. Building 

on existing coastal, coral reef, and estuarine networks 

made up of shipboard and remote autonomous systems 

is a cost-efficient approach for establishing a U.S. 

coastal and estuarine network. NOAA is well poised 

to enhance many of its capabilities within NOAA that 

can be used to establish an ocean and Great Lakes 

acidification ecosystem monitoring network to characterize 

the carbon chemistry of these environments.

New technology and enabling activities

still need to be developed or adapted to improve 

monitoring efforts, including new biogeochemical 

sensors for carbon species, gliders, genomic tags, and 

a center of expertise for carbon measurements.

Similar monitoring platforms will be used to study 

ecosystem responses. Critical changes in community 

metabolic processes must be assessed to determine the 

ultimate “carbon thresholds” for ecosystem responses. 

Laboratory experiments, mesocosm, and field studies 

will be carried out to describe physiological responses 

to acidified waters. Species likely to respond include 

those vulnerable to direct effects and those vulnerable 

via indirect effects, such as trophic cascades.

Modeling studies of large-scale changes in water 

chemistry will help us understand and predict ecosystem 

responses. Models will be used to inform development 

of adaptation strategies to ocean and lake acidification. 

New modeling approaches also will be explored.

MONITOR 

ASSESS 

FORECAST

MANAGE

SYNTHESIZE

ENGAGE

Left to right: Left, Research cruises 

will continue to be essential to ocean 

acidification monitoring and research. 

Shown is NOAA Ship Ronald H. Brown, 

a state-of-the-art oceanographic and 

atmospheric platform. Autonomous 

underwater vehicle (AUV) in foreground. 

(Photo credit: NOAA); Center: The Wave 

Glider, a solar-powered AUV, is being 

tested for use with a variety of sensors to 

detect ocean acidifcation. (Photo credit: 

With permission from Liquid Robotics, 

Inc.); Right, First ocean acidification 

mooring deployed in Gulf of Alaska at 

Papa Station, 2007 (Photo credit: NOAA).

NOAA Ocean and Great Lakes Acidification Research Plan | 7
REGIONAL 

APPROACH

6 regions

Alaska Region

West Coast Region

Pacific Islands Region

Northeast Region

Great Lakes Region

Southeast Atlantic 

and Gulf of Mexico Region

Regions for ocean and lake acidification 

monitoring and research are shown 

in the tan shaded areas.

MONITOR

ASSESS

FORECAST

MANAGE

SYNTHESIZE

ENGAGE

•	 Ocean acidification 

•	 (OA) moorings

•	 Coral reef monitoring sites

•	 OA sensors on NOAA 

research vessels and 

Voluntary Observing 

Ships (VOS)

•	 Single species experiments

•	 Multi-species mesocosm 

experiments

•	 Test/evaluate existing 

global and regional models 

•	 Develop high resolution 

physical-biogeochemicalecosystem models

•	 Coastal early 

warning system

•	 Socioeconomic models and 

decision support tools

•	 Test mitigation 

approaches in lab

•	 Data management 

coordination, 

synthesis, integrated 

synthesis activities

•	 Education and 

outreach planning 

•	 Curricula and product 

development

8 | September 2010

All six themes of the research plan will be executed at the regional level with strong 

national coordination. The Implementation Timeline can be viewed on page 10 of 

this document.
ALASKA

The Alaska region produces nearly 50 percent 

of all U.S. seafood. Climate change, most 

notably sea ice loss and ocean warming, 

already affects habitats in this sensitive region. 

Combined effects of ocean acidification and

climate change on food webs and, ultimately,

seafood production are not known. Existing

food web models for the region will be 

used to predict changes in productivity

upon incorporating ocean acidification data

and climate change scenarios. At present, 

the region is sparsely monitored. The 

first dedicated ocean acidification buoy

to be implemented is sited in the Gulf of 

Alaska. Monitoring will be implemented in 

Katchemak Bay, Bering Sea, Arctic Ocean,

Gulf of Alaska and southeast Alaska. 

WEST COAST

Commercial fisheries in the West coast region

generated $504 million in ex-vessel revenue from 

finfish and shellfish in 2008. Deep, nutrient-rich

waters brought to the surface by the coastal 

upwelling process is a life support system for the 

region’s fisheries. However, coastal upwelling

also brings some of the oldest and most 

corrosive upwelled waters to the surface. Ocean 

acidification has been implicated in the near-total

failure of the $100 million a year oyster industry 

over the past four out of five years. To provide

a basis for an “early warning system” for ocean 

acidification and to follow its long-term patterns,

the California Current System from Canada to 

Mexico will be monitored. Impacts on key species 

and downstream effects on overall carbon cycling

and rates of ocean acidification will be examined.

 

PACIFIC ISLANDS

Home to a large percentage of the Nation’s most

biologically diverse coral reef systems, the coral 

reefs of the Main Hawai’ian Islands are valued at 

nearly $10 billion (in 2002 dollars) with an annual 

benefit of $385 million. The region also provides

habitats for many endangered marine mammals. 

With few pressures from pollution, fishing,

tourism, recreation, and coastal development in

remote areas of the Hawai’ian Archipelago, the 

region will focus on coral reef monitoring and 

understanding and assessing the effects of ocean

acidification on reef growth and biodiversity. 

Because of their naturally rich CO2 environments, 

shallow hydrothermal vents will serve as models 

for fine-scale changes in ocean chemistry. The

largest international effort in the program,

a Coral Reef Ocean Acidification Monitoring

Network , is this region’s highest priority.

Already experiencing widespread 

eutrophication and associated oxygen 

depletion, commonly referred to as “dead 

zones,” the entire $600 million commercial 

fishery in the Gulf and the entire $550 million 

commercial fishery along the Atlantic may be 

affected by ocean acidification. The Southeast 

Atlantic/Gulf of Mexico region’s research 

and monitoring will focus on the interaction 

among these processes, as well as coral 

health, which has suffered significant declines 

over the past several decades. Sustained 

monitoring is coupled to focused hypothesisguided studies and modeling. Impacts on 

seagrass and estuaries also will be studied, 

as will historical responses, where feasible.

SOUTHEAST ATLANTIC AND 

GULF OF MEXICO

Many of the 1,000 fish species in the Northeast 

region support a large fishing industry, which 

in 2006 produced fish and shellfish landings 

worth over $1.2 billion. The saturation state 

of surface waters off the coast of New England 

are expected to decline sooner than other 

areas of the Northeast, especially during the 

winter months. Hypoxia, a growing threat in 

the region’s estuaries, may be adding CO2 to 

Northeast waters. The combined effects of 

hypoxia and ocean acidification are poorly 

understood. In addition to response and 

modeling studies across the food web, a 

monitoring program will focus on the Northeast 

U.S. continental shelf ecosystem. Marine 

protected areas are potential sentinel sites for 

existing and new monitoring programs.

NORTHEAST

Approximately 34 million people depend 

on the Great Lakes for drinking water. Its 

ecosystems currently face a number of grave 

environmental threats, including ecological 

impacts from roughly 185 non-native aquatic 

species, toxic and nutrient pollution, habitat 

destruction, animal and human disease 

outbreaks, and climate change. Patterns of 

lake acidification with respect to atmospheric 

CO2 patterns and these stressors are not well 

understood. Because invasive zebra mussels 

have played an increasingly important role in 

the energy and nutrient cycles of the Great 

Lakes, impacts of elevated CO2 on invasive and 

native bivalve populations will be investigated. 

A monitoring network will be implemented 

across all five lakes and all seasons.

GREAT LAKES

King crab 

Euphausiids 

Deep-sea corals . Walleye pollock

Bivalves (geoduck, oysters) . Zooplankton 

Deep-sea coral . Sea urchins 

Dungeness crab . Pacific sardines . Rockfish

Reef–building, crustose coralline algae

Coral reef diversity . Hawaiian monk seal . Hawksbill 

and green sea turtle . Protected cetaceans

ORGANISMS OF NEAR-TERM FOCUS

Organisms of near-term focus are species important to the region’s ecosystems and economy. These species 

could be directly affected by acidification or through disturbance of species that they depend on for food.

Seagrass

Calcifying plankton . Oysters . Reef-building corals

White, brown, and pink shrimp

Lobsters . Primary producers . Scallops . Clams 

Mussels . Oysters . Deep-sea coral . Shortnose 

sturgeon . Flounder . Black sea bass . Right whale

Invasive species: Zebra and quagga mussels

Native species: Unionid bivalves 

(42 species) and Amphipods

NOAA Ocean and Great Lakes Acidification Research Plan | 9
IMPLEMENTATION TIMELINE

The Fiscal Year 2010 (FY10) enacted funding for ocean acidification activities in NOAA was $5.5M. In FY11, the 

President’s Budget request is $11.6M for research on ocean acidification. NOAA requests an increase in FY11 to 

implement a NOAA Integrated Ocean Acidification (OA) Program. The OA Program will support research and 

long-term monitoring of ocean acidification for assessing climate change impacts on living marine resources.

NOAA is actively working to implement the recently enacted Federal Ocean Acidification Research and 

Monitoring Act, which creates an Ocean Acidification Program within NOAA. 

EXPECTED OUTCOMES

MONITOR

ASSESS

FORECAST

MANAGE

SYNTHESIZE

ENGAGE

2010

2011

2012

2013

2014

2015

2016

Deploy and maintain OA moorings and coral reef monitoring sites

Instrument and maintain OA sensors on NOAA research and VOS ships 

CLIVAR/CO2 cruises

Single species experiments (vulnerable economically important and protected species)

Multi-species and mesocosm experiments

Test and evaluate existing global and regional models 

Develop high resolution, physical – biogeochemical – ecosystem models

Develop coastal early warning system

Develop socio-economic models and decision tools

Test mitigation approaches in lab

Data management and synthesis

Integrated synthesis workshops and reports

Education and outreach planning - Develop curricula and outreach products

Expected Outcomes

Conservation of our marine ecosystems and 

sustenance of the services our oceans, coastal, and 

Great Lakes ecosystems in the face of climate change

Integrated assessments of ecological 

and societal impacts in each region

Early warning system for U.S. 

coastal waters and Great Lakes

Improved public understanding of ocean acidification 

and stewardship of the oceans and Great Lakes

Themes

Monitor

Assess

Forecast

Manage

Synthesize

Engage

10 | September 2010
INFRASTRUCTURE

As part of the Federal Ocean Acidification Research and Monitoring Act of 2009, 

the United States Joint Subcommittee on Ocean and Science Technology (JSOST) 

is designated as the subcommittee that coordinates federal activities on ocean 

acidification. Under this plan, JSOST established the Interagency Working Group on 

Ocean Acidification (IWGOA) to develop the strategic research and monitoring plan to 

guide federal research on ocean acidification. NOAA is the lead agency of the IWGOA.

PARTNERSHIPS

The development of a program to fulfill the NOAA Ocean and Great Lakes Acidification 

Research Plan benefits from a coordinated national research effort closely linked 

with other U.S. federal and state government, university, and private efforts.

Interagency Partners 

National Science Foundation

National Aeronautics and 

Space Administration

Environmental Protection Agency

U.S. Fish and Wildlife Service 

U.S. Geological Survey 

Bureau of 

Ocean Energy 

Management, 

Regulation and 

Enforcement

Department 

of the Navy

Department 

of State

International cooperation

will be coordinated through the Surface 

Ocean–Lower Atmosphere Study (SOLAS) 

and Integrated Marine Biogeochemistry 

and Ecosystem Research (IMBER) Working 

Group on Ocean Acidification. This 

international group has two main goals: 

(1) coordinate international research 

efforts in ocean acidification; and (2) 

undertake synthesis activities in ocean 

acidification at the international level.

NOAA OCEAN ACIDIFICATION STEERING COMMITTEE

Richard Feely 

Pacific Marine 

Environmental 

Laboratory

richard.a.feely@noaa.gov

Elizabeth Jewett

National Centers for 

Coastal Ocean Science

libby.jewett@noaa.gov

Michael Sigler

Alaska Fisheries 

Science Center

mike.sigler@noaa.gov John Stein

Northwest Fisheries 

Science Center

john.e.stein@noaa.gov Rik Wanninkhof

Atlantic Oceanographic and 

Meteorological Laboratory

rik.wanninkhof@noaa.gov

Dwight Gledhill

Atlantic Oceanographic and 

Meteorological Laboratory

dwight.gledhill@noaa.gov

Felipe Arzayus

Ocean Exploration 

and Research

felipe.arzayus@noaa.gov

www.pmel.noaa.gov/co2