**WRITTEN TESTIMONY OF**

> **RICHARD A. FEELY, Ph.D.**
>
> **PACIFIC MARINE ENVIRONMENTAL LABORATORY**
>
> **NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION**
>
> **U.S DEPARTMENT OF COMMERCE**
>
> **HEARING ON**
>
> **EFFECTS OF CLIMATE CHANGE AND OCEAN ACIDIFICATION ON LIVING MARINE
> RESOURCES**
>
> **BEFORE THE**
>
> **COMMITTEE ON COMMERCE, SCIENCE AND TRANSPORTATION**
>
> **SUBCOMMITTEE ON OCEANS, ATMOSPHERE,**
>
> **FISHERIES AND COAST GUARD**
>
> **UNITED STATES SENATE**
>
> **MAY 10, 2007**

**Introduction**

Good morning Chairman Cantwell and members of the Subcommittee. Thank
you for giving me the opportunity to speak with you today on the short-
and long-term impacts of ocean acidification on marine resources. My
name is Richard Feely, I am a Supervisory Chemical Oceanographer at the
Pacific Marine Environmental Laboratory of the National Oceanic and
Atmospheric Administration (NOAA) in Seattle, WA. My personal area of
research is the study of the oceanic carbon cycle and its impact on
marine organisms. I have worked for NOAA for more than 32 years and have
published more than 160 peer-reviewed scientific journal articles, book
chapters and technical reports. I serve on the U.S. Carbon Cycle Science
Program Scientific Steering Group and I am the co-chair of the U.S.
Repeat Hydrography Program Scientific Oversight Committee. For today,
you have asked me to provide my insights on ocean acidification and its
effect on living marine ecosystems. Most of my comments below are
derived from the Royal Society Report, *"Ocean Acidification Due to
Increasing Atmospheric Carbon Dioxide"* (Raven *et al*., 2005) and the
recent U.S. report, derived from a workshop held jointly by the National
Science Foundation (NSF), NOAA, and the U.S. Geological Survey, entitled
*"Impacts of Ocean Acidification on Coral Reefs and Other Marine
Calcifiers"* (Kleypas *et al.*, 2006).

**Ocean Acidification**

Over the past 200 years the release of carbon dioxide (CO~2~) from our
collective industrial and agricultural activities has resulted in
atmospheric CO~2~ concentrations that have increased by about 100 parts
per million (ppm). The atmospheric concentration of CO~2~ is now higher
than experienced on Earth for at least the last 800,000 years, and is
expected to continue to rise, leading to significant temperature
increases in the atmosphere and oceans by the end of this century. The
oceans have absorbed approximately 525 billion tons of carbon dioxide
from the atmosphere, or about one third of the anthropogenic carbon
emissions released during this period (Sabine and Feely, 2007). This
natural process of absorption has benefited humankind by significantly
reducing the greenhouse gas levels in the atmosphere and minimizing some
of the impacts of global warming. However, the ocean's daily uptake of
22 million tons of carbon dioxide is starting to have a significant
impact on the chemistry and biology of the oceans. For more than 25
years, NOAA and NSF have co-sponsored repeat hydrographic and chemical
surveys of the world oceans, documenting the ocean's response to
increasing amounts of carbon dioxide being emitted to the atmosphere by
human activities. These surveys have confirmed that the oceans are
absorbing increasing amounts of carbon dioxide. Both the hydrographic
surveys and modeling studies reveal that the chemical changes in
seawater resulting from the absorption of carbon dioxide are lowering
seawater pH (Feely *et al.*, 2004; Orr *et al.*, 2005; Caldeira and
Wickett, 2005; Feely *et al.*, in press). It is now well established
that the pH of our ocean surface waters has already fallen by about 0.1
units from an average of about 8.21 to 8.10 since the beginning of the
industrial revolution (on the logarithmic pH scale, 7.0 is neutral
(e.g., water), with points higher on the scale being "basic" and points
lower being "acidic."). Estimates of future atmospheric and oceanic
carbon dioxide concentrations, based on the Intergovernmental Panel on
Climate Change (IPCC) CO~2~ emission scenarios and general circulation
models, indicate that by the middle of this century atmospheric carbon
dioxide levels could reach more than 500 parts per million (ppm), and
near the end of the century they could be over 800 ppm. This would
result in a surface water pH decrease of approximately 0.4 pH units as
the ocean becomes more acidic, and the carbonate ion concentration would
decrease almost 50 percent by the end of the century (Orr *et al.*,
2005). To put this in historical perspective, this surface ocean pH
decrease would result in a pH that is lower than it has been for more
than 20 million years (Feely *et al*., 2004). When CO~2~ reacts with
seawater, fundamental chemical changes occur that cause a reduction in
seawater pH. The interaction between CO~2~ and seawater also reduces the
availability of carbonate ions, which play an important role in shell
formation for a number of marine organisms such as corals, marine
plankton, and shellfish. This phenomenon, which is commonly called
"ocean acidification," could affect some of the most fundamental
biological and geochemical processes of the sea in coming decades. This
rapidly emerging issue has created serious concerns across the
scientific and fisheries resource management communities.

**Effects of Ocean Acidification on Coral Reefs**

Many marine organisms that produce calcium carbonate shells studied thus
far have shown detrimental effects due to increasing carbon dioxide
levels in seawater and the resulting decline in pH. For example,
increasing ocean acidification has been shown to significantly reduce
the ability of reef-building corals to produce their skeletons,
affecting growth of individual corals and making the reef more
vulnerable to erosion (Kleypas *et al.*, 2006). Some estimates indicate
that, by the end of this century, coral reefs may erode faster than they
can be rebuilt. This could compromise the long-term viability of these
ecosystems and perhaps impact the thousands of species that depend on
the reef habitat. Decreased calcification may also compromise the
fitness or success of these organisms and could shift the competitive
advantage towards organisms that are not dependent on calcium carbonate.
Carbonate structures are likely to be weaker and more susceptible to
dissolution and erosion. In long-term experiments corals that have been
grown under lower pH conditions for periods longer than one year have
not shown any ability to adapt their calcification rates to the low pH
levels. In fact, a recent study showed that the projected increase in
CO~2~ is sufficient to dissolve the calcium carbonate skeletons of some
coral species (Fine and Tchernov, 2007).

**Effects of Ocean Acidification on Fish and Shellfish**

Ongoing research is showing that decreasing pH may also have deleterious
effects on commercially important fish and shellfish larvae. Both king
crab and silver seabream larvae exhibit very high mortality rates in
CO~2~-enriched waters (Litzow *et al*., submitted; Ishimatsu *et al*.,
2004). Some of the experiments indicated that other physiological
stresses were also apparent. Exposure of fish to lower pH levels can
cause decreased respiration rates, changes in blood chemistry, and
changes in enzymatic activity. The calcification rates of the edible
mussel (*Mytilus edulis*) and Pacific oyster (*Crassostrea gigas*)
decline linearly with increasing CO~2~ levels (Gazeau *et al*., in
press). Squid are especially sensitive to ocean acidification because it
directly impacts their blood oxygen transport and respiration (Pörtner
*et al*., 2005). Sea urchins raised in lower-pH waters show evidence for
inhibited growth due to their inability to maintain internal acid-base
balance (Kurihara and Shirayama., 2004). Scientists have also seen a
reduced ability of marine algae and free-floating plants and animals to
produce protective carbonate shells (Feely *et al.*, 2004; Orr *et al.*,
2005). These organisms are important food sources for other marine
species. One type of free-swimming mollusk called a pteropod is eaten by
organisms ranging in size from tiny krill to whales. In particular,
pteropods are a major food source for North Pacific juvenile salmon, and
also serve as food for mackerel, pollock, herring, and cod. Other marine
calcifiers, such as coccolithophores (microscopic algae), foraminifera
(microscopic protozoans), coralline algae (benthic algae), echinoderms
(sea urchins and starfish), and mollusks (snails, clams, and squid) also
exhibit a general decline in their ability to produce their shells with
decreasing pH (Kleypas *et al*., 2006).

**Effects on Marine Ecosystems**

Since ocean acidification research is still in its infancy, it is
impossible to predict exactly how the individual species responses will
cascade throughout the marine food chain and impact the overall
structure of marine ecosystems. It is clear, however, from the existing
data and from the geologic record that some coral and shellfish species
will be reduced in a high-CO~2~ ocean. The rapid disappearance of many
calcifying species in past extinction events has been attributed, in
large part, to ocean acidification events (Zachos *et al.*, 2005). Over
the next century, if CO~2~ emissions are allowed to increase as
predicted by the IPCC CO~2~ emissions scenarios, mankind may be
responsible for increasing oceanic CO~2~ and making the oceans more
corrosive to calcifying organisms than anytime since the last major
extinction, over 65 million years ago. Thus, the decisions we make about
our use of fossil-fuels for energy over the next several decades will
probably have a profound influence on makeup of future marine ecosystems
for centuries to millennia.

**Economic Impacts**

The impact of ocean acidification on fisheries and coral reef ecosystems
could reverberate through the U.S. and global economy. The U.S. is the
third largest seafood consumer in the world with total consumer spending
for fish and shellfish around \$60 billion per year. Coastal and marine
commercial fishing generates upwards of \$30 billion per year and
employs nearly 70,000 people (NOAA Fisheries Office of Science and
Technology; http://www.st.nmfs.gov/st1/fus/fus05/index.html). Nearly
half of the U.S. fishery is derived from the coastal waters surrounding
Alaska. Increased ocean acidification may directly or indirectly
influence the fish stocks because of large-scale changes in the local
ecosystem dynamics. It may also cause the dissolution of the newly
discovered deepwater corals in the Alaskan Aleutian Island region. Many
commercially important fish species in this region depend on this
particular habitat for their survival.

Healthy coral reefs are the foundation of many viable fisheries, as well
as the source of jobs and businesses related to tourism and recreation.
In the Florida Keys, coral reefs attract more than \$1.2 billion in
tourism annually. In Hawaii, reef-related tourism and fishing generate
\$360 million per year, and their overall worth has been estimated at
close to \$10 billion. In addition, coral reefs provide vital protection
to coastal areas that are vulnerable to storm surges and tsunamis.

**Conclusions**

Ocean acidification may be one of the most significant and far-reaching
consequences of the buildup of anthropogenic carbon dioxide in the
atmosphere. Results from laboratory, field and modeling studies, as well
as evidence from the geological record, clearly indicate that marine
ecosystems are highly susceptible to the increases in oceanic CO~2~ and
the corresponding decreases in pH. Corals and other calcifying organisms
will be increasingly affected by a decreased capability to produce their
shells and skeletons. Other species of fish and shellfish will also be
negatively impacted in their physiological responses due to a decrease
in pH levels of their cellular fluids. Because of the very clear
potential for ocean-wide impacts of ocean acidification at all levels of
the marine ecosystem, from the tiniest phytoplankton to zooplankton to
fish and shellfish, we can expect to see significant impacts that are of
immense importance to mankind. Ocean acidification is an emerging
scientific issue and much research is needed before all of the
ecosystems responses are well understood. However, to the limit that the
scientific community understands this issue right now, the potential for
environmental, economic and societal risk is also quite high, hence
demanding serious and immediate attention. For these reasons, the
national and international scientific communities have recommended a
coordinated scientific research program with four major themes; (1)
carbon system monitoring; (2) calcification and physiological response
studies under laboratory and field conditions; (3) environmental and
ecosystem modeling studies; and (4) socio-economic risk assessments.
This research will provide resource managers with the basic information
they need to develop strategies for protection of critical species,
habitats and ecosystems, similar to what has already been developed for
coral reef managers with the publication of *the Reef Manager's Guide*
by the U.S. Coral Reef Task Force to help local and regional reef
managers reduce the impacts of coral bleaching to coral reef ecosystems.

Thank you for giving me this opportunity to address this Subcommittee. I
look forward to answering your questions.

**Selected References**

Caldeira, K., and M.E. Wickett, Ocean model predictions of chemistry
changes from

> carbon dioxide emissions to the atmosphere and ocean. Journal of
> Geophysical Research (Oceans) 110, C09S04, doi:10.1029/2004JC002671,
> 2005.

Feely, R. A., C. L. Sabine, K. Lee, W. Berrelson, J. Kleypas, V. J.
Fabry, and F. J.

> Millero, 2004, Impact of anthropogenic CO~2~ on the CaCO~3~ system in
> the oceans, Science, 305(5682): 362-366.

Feely, R.A., J. Orr, V.J. Fabry, J.A. Kleypas, C.L. Sabine, and C.
Landgon (in press):

> Present and future changes in seawater chemistry due to ocean
> acidification. AGU Monograph on \"The Science and Technology of Carbon
> Sequestration\".

Fine, M. and D. Tchernov (2007). Scleractinian coral species survive and
recover from

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Gazeau, F., Quiblier, C., Jeroen M. Jansen, J. M. Jean-Pierre Gattuso,
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Ishimatsu, A., Kikkawa, T., Hayashi, M., Lee, K.-S., and . J. Kita
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731 --

741\.

Kleypas, J.A., R.A. Feely, V.J. Fabry, C. Langdon, C.L. Sabine, and L.L.
Robbins

> (2006): Impacts of ocean acidification on coral reefs and other marine
> calcifiers: A guide to future research. Report of a workshop held
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> U.S. Geological Survey, 88 pp.

Kurihara, K. and Shirayama, Y. (2004): Impacts of increased atmospheric
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Marshall, P. and H. Schuttenberg (2006): A Reef Manager's Guide to Coral
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Great Barrier Ref Marine Park Authority, Townsville, Australia, 139pp.

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A. and S. A. Payne, (submitted for publication). Calcite undersaturation
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Orr, J. C., V. J. Fabry, O. Aumont, L. Bopp, S. C. Doney, R. A. Feely,
A. Gnanadesikan,

> N. Fruber, A. Ishida, F. Joos, R. M. Key, K. Lindsay, E. Maier-Reimer,
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Pörtner, H.O., M. Langenbuch, and B. Michaelidis (2005) Synergistic
effects of

> temperature extremes, hypoxia, and increases in CO2 on marine animals:
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> J. Turley, C. Watson, A. (2005) Acidification due to increasing carbon
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> Thomas, M. Nicolo, I. Raffi, L. J. Lourens, H. McCarren, and D. Kroon,
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