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currentthe journal of Marine education
Volume 25 • Number 1 • 2009
Special iSSue featuring ocean acidification—froM ecological iMpactS to policy opportunitieS
In many parts of the United States, the word “seafood” is nearly
synonymous with carbonate shell-forming marine species—
shellfish like oysters, clams and scallops, and crustaceans like
lobster, crabs, and shrimp. Adults and juveniles of these very
economically valuable animals, along with less familiar shelled
creatures like sea urchins, planktonic snails called pteropods,
and some types of phytoplankton, are food for a variety of
predators and fuel food webs. Commercial harvests of shellfish,
crustaceans, and finfish sustain seafood industries that support
many coastal economies. If ocean acidification slows the growth
of marine organisms’ carbonate shells and skeletons, it will
endanger many individual plants and animals, whose declines
will in turn harm entire marine food webs, aquatic environ-
ments, and economies (Doney et al. 2009).
AN EcoNoMic ASSESSMENt of u.S. coMMERciAl
fiSHiNg AND AquAcultuRE
Commercial fishing is a big business today in the United States,
and carbonate shell-forming species provide a large portion of
its revenues. In 2006, the total value of commercial sales from
fishermen to middlemen was $4.0 billion; shellfish and crusta-
ceans provided 50% of that amount (Figure 1; Andrews et al.
2007). The contribution varies by region around the country
(Figure 1); shellfish are more important in the New England and
mid- to south Atlantic, crustaceans contribute greatly to New
England and Gulf of Mexico fisheries, and predatory finfish (e.g.
pollock, salmon, and tuna) dominate the Alaskan, Hawaiian, and
Pacific-territory fisheries. Subsequent processing, wholesale, and
distribution of all harvests generated retail sales of $70 billion
in 2006, leading to $35 billion added to the U.S. gross national
product that year (Table 1; Cooley and Doney, submitted).
Across the country, the number of jobs generated by U.S.
commercial fisheries also grows markedly from catch to retail
sale. The total number of jobs in the United States supported
by commercial fishing is difficult to constrain, because industry
ocean acidificaTion’s impacT on fisheries and socieTies:
a u.s. perspecTive
By Sarah R. Cooley and Scott C. Doney
Many valuable commercial fisheries and aquaculture facilities
harvest ocean shellfish (e.g., clams, scallops) and crustaceans (e.g., lobsters, crabs) that form calcium carbonate
shells. These animals, along with corals, may be particularly sensitive to changes in seawater chemistry driven by
human fossil fuel use. Finfish may also be affected indirectly owing to loss of prey and habitat. Ocean acidification
impacts could decrease future fishing revenues and harm communities that depend economically and culturally
on marine resources.
figure 1. Primary revenue from u.S. commercial fishing (the
amount paid to fisherman for the catch, sometimes called ex-vessel
revenue) for the u.S. as a whole and broken up by region. Data
are for 2006 from National Marine fisheries Service statistics. the
pie charts are divided into groups of species and the darker colors
indicate those groups that are directly sensitive to ocean acidifica-
tion, such as shellfish and crustaceans.
Recreational
Total economic impact
(sales, income, jobs) $82 billion
Jobs supported ~530,000
Commercial
Primary sales (the amount
paid to fishermen for catch) $4 billion
Retail seafood sales $70 billion
Net contribution to GNP $35 billion
table 1. Revenues from u.S. recreational (gentner and Steinback
2008) and commercial (NMfS statistics) fishing (uS dollars).

current the journal of Marine education
Volume 25 • Number 1 • 2009
16 Special iSSue featuring ocean acidification—froM ecological iMpactS to policy opportunitieS
surveys do not count self-employed fishermen and may not
count all middlemen. However, the efforts of a few fishermen
support many jobs in seafood processing, transportation, prepa-
ration, and sales. Commercial fish processing and wholesaling
nationwide supported about 70,000 jobs in 2006.
Recreational fishing also adds economic benefits because recre-
ational fishermen travel, purchase permits and equipment, and
patronize supporting industries (Figure 2). This results in the
generation of jobs, profits, tax revenues, and business-to-business
revenue. In 2006 (the latest date for which data is available), $24
billion of income, a total impact of $82 billion from sales and
services, and almost 530,000 jobs (Table 1) were created in the
United States by recreational saltwater fishing for a total economic
impact of $82 billion that year (Gentner and Steinback 2008).
Growing aquaculture industries worldwide also depend heavily
on carbonate-forming organisms like shellfish and crustaceans.
In total, 20-25% of the global per capita human consumption
of animal protein comes from marine harvests, but patterns of
consumption vary widely, and developing and coastal nations
often consume high per capita quantities of aquaculture
products. In the United States, aquaculture generated $1 billion
of primary sales in 2005 (Andrews et al. 2007), approximately
25% of the value of commercial wild fish harvests. Most aqua-
culture facilities are located in coastal areas, which will also
experience ocean acidification.
Species pH Shell dissolution
Increased
mortality Other
Mussel M. edulis 7.1 yes yes 25% decrease in calcification
Oyster C. gigas 7.1 n/a n/a 10% decrease in calcification
Giant scallop P. magellanicus < 8.0 n/a n/a Decrease in fertilization, development
Clam M. mercenaria 7.0-7.2 yes yes
Crab N. puber 6.0-8.0 yes n/a Lack of pH regulation
Sea urchin S. purpuratus 6.2-7.3 yes n/a Lack of pH regulation
Dogfish S. canicula 7.7 n/a yes
Sea bass D. labrax 7.25 n/a n/a Reduced feeding
table 2. Responses of commercially harvested species to laboratory ocean acidification experiments “n/a”—not available, response is unknown.
figure 3. the American lobster (Homarus americanus). found
along the Atlantic coast of North America, American lobsters
live a solitary and largely nocturnal existence, feeding on crabs,
mollusks, sea urchins, fish, and even macroalgae. changes asso-
ciated with ocean acidification may impact lobsters both directly
since they use calcium carbonate to form their shells and indirectly
through impacts to their food sources.
figure 2. Saltwater recreational fishing is critical to local and
regional economies throughout the united States (SE Alaskan
waters pictured). the National Marine fisheries Service estimates
that 25 million saltwater anglers fished 127 million days in the
coastal states of the u.S. in 2006.