Shellfish are cultured in every coastal state but three primary production centres are located along coasts of the northeastern region, the Gulf of Mexico and the Pacific Northwest, primarily in Washington State. Shellfish production increased significantly from 1998 to 2008 representing 35 percent of the total industry value in 2008 generating USD 323 million with the average Annual Percentage Rate (APR) of six primary cultured species reaching 12.8 percent.
The first successful spawning of channel catfish in ponds was reported in 1914 (Tucker et al., 2004) and they were routinely propagated in hatchery ponds of many state and federal facilities during the 1920s for stocking. In the early 1960s, catfish farming for food fish began in earnest and by 1966 over 4 000 ha were farmed in Arkansas. In 1967, a group of catfish farmers formed a partnership to construct a processing plant, and in 1971, the first feed mill was built by a farmer’s cooperative. These developments provided the infrastructure to support significant industry expansion and catfish became the dominant species in the aquaculture sector. Harvest yields vary considerably but the industry average is 4 000/kg/ha (Tucker et al., 2004). In 2008, catfish represented 65 percent of the value of the finfish sector and 42 percent of the value of the entire sector including shellfish. Catfish production in 2008 of 234 000 tonnes was valued at USD 390 million.
Atlantic salmon production began in the 1970s in North America as an industry with a small number of entrepreneurs using ocean net pens in the Pacific Northwest. Opposition developed around concerns over environmental impacts and prevented industry expansion. Production of 17 000 tonnes in 2008 was valued at USD 45 million. Production density varies from stocking to harvest, but a range of 15–25 kg/m3 is standard in the industry. Production costs are in the range of USD 5–7/kg (Forster, 2002).
Harvest of wild shellfish has occurred for thousands of years and in the early 1900s evolved from wild harvest to the harvest of shellfish from enhanced beds. As hatchery technology improved in the 1960s, the oyster industry became more reliant on hatchery seed. With the exception of blue mussels which are primarily collected as seed recruiting from the wild, and some natural sets of American oysters and hard clams, seed for culture of American and Pacific oysters, hard clams and Manila clams are hatchery produced.
The importance of aquaculture employment to local economies varies considerably on a regional basis. The impact is greatest in the cluster of states in the southeastern Delta region which is the centre of the channel catfish industry. The three States of Arkansas, Louisiana and Mississippi provide jobs to 3 936 people or 37 percent of the nation’s total direct employment in aquaculture (Table 1). With its dynamic shellfish sector raising primarily oysters and clams, Washington State alone supports 1 284 positions equal to 12 percent of the direct American aquaculture employment.
Table 1: States with aquaculture payroll exceeding USD 10 million in 2005.
The top channel catfish producing area is in the southeast region known as the Delta, and includes the alluvial valley along the Mississippi River in western Mississippi, northeastern Louisiana, and southeastern Arkansas. This region has 34 642 ha in ponds and includes 86 percent of the land area in catfish production. A secondary production center is about 300 km to the east in the Blackland Prairie at the center of the border between Mississippi and Alabama. Salmon farming in coastal net pens is consolidated in northeastern Maine. States with the highest number of farms include Louisiana (873), Mississippi (403), Alabama (215), Arkansas (211), and Florida (359).
Culture of American oysters, hard clams and mussels occurs in the northeastern region and along the Atlantic coast. American oysters and hard clams are grown in the Gulf of Mexico. American and Pacific oysters, Manila clams, geoduck clams, and mussels are grown along the Pacific coast, primarily in the northwest. In addition, there is a significant hard clam industry in Florida, centered in coastal waters of Dixie, Levy, Charlotte and Lee Counties on the western Gulf coast, and in Brevard and Indian River Counties on the Atlantic coast.
Almost 50 percent of American farms use fresh groundwater for production, and surface water was also used by 1 314 farms in 2005. Freshwater aquaculture on private lands involved 3 127 farms using 147 945 ha in 2005, while leased land in freshwater production covered 52 366 ha or 24 percent of freshwater surface area under production. In 2005, 1 203 farms used 132 534 ha for saltwater farming of shellfish and 779 farms leased an additional 107 302 ha.
Seafood consumption in the United States of America has risen slowly from 5.7 kg per capita in 1980 to 6.8 kg per capita in 1990. Since then, consumption increased even more slowly to 6.9 kg per capita in 2000 and 7.2 kg in 2009. Consumption may increase in the future as the US Food and Drug Administration and the American Heart Association have recommended a doubling of seafood consumption to realize the many health benefits attributed to consumption of seafood and the omega-3 fatty acids they contain.
Shellfish valued at USD 323 million comprise 35 percent of total industry value. Cultured shellfish include Pacific and American cupped oysters (Crassostrea gigas, Crassostrea virginica), hard clams (Mercenaria mercenaria), Manila clams (Venerupis philippinarum) and blue mussels (Mytilus edulis). On the Pacific coast farming of the native olympia oyster (Ostreola conchaphila), and geoduck clam (Panopea generosa) are a small industry component. Farmed crustaceans include the red swamp crawfish (Procambarus clarkii) and the whiteleg shrimp (Penaeus vannamei).
Most of the finfish being cultured are native species except for the tilapia, cyprinids and barramundi. Others, such as the channel catfish and rainbow trout are indigenous, but are also being cultured outside their native range. Cultured molluscs are primarily indigenous in the Atlantic Ocean and Gulf of Mexico except for the European flat oyster (Ostrea edulis). In contrast, the shellfish industry on the Pacific West Coast produces almost exclusively introduced species including the Pacific cupped oyster, eastern oyster, European flat oyster and Manila clam.
Species which have been the focus of genetic selection programmes to improve production traits such as growth, yield and disease resistance are the Atlantic salmon, channel catfish, rainbow trout, and the eastern oyster and Pacific cupped oyster.
Channel catfish are grown primarily in embankment or levee ponds which are built on flat land by removing soil from the area that will be the pond bottom and using that soil to form levees or embankments around the pond perimeter. The ideal size of catfish ponds has changed in recent years with farmers reporting that smaller ponds around four hectares are easier to manage and feed than larger ponds of eight to ten hectares. Original pond depths of around one meter are now approaching two meters which increases longevity and conserves water. Other finfish are grown in land-based raceways, ponds or circular tanks that have a continuous flow of freshwater, or a recirculating system with filters for water treatment. Rainbow trout farmers use almost exclusively flow-through raceways, while producers of hybrid striped bass, tilapia, yellow perch, and cyprinids use ponds, cages and tanks. Recirculating systems are used for high value species or fish destined for high value live markets to cover the increased operational costs of these systems. Atlantic salmon, cobia, sixfinger threadfin, and longfin yellowtail are grown in near-shore ocean gravity net pens or submersible cages.
Shellfish growers use bottom culture methods extensively for oyster and clam culture, employing direct planting, mesh bottom culture bags and rack bag systems. Off-bottom culture systems are used primarily by mussel growers and include long-line and raft systems with hanging lines.
Despite declines over the last decade, the finfish sector still dominates the industry with production valued at almost twice that of shellfish. Channel catfish is the predominant species representing 42 percent of total value at USD 390 million in 2008. Finfish value was relatively stable over the decade for most other finfish species which include cyprinids, hybrid striped bass, tilapia and small amounts of American yellow perch and Arctic char. The value of Atlantic salmon rose early in the decade but then declined as a result of widespread losses due to outbreaks of infectious salmon anemia. Overall, finfish production accounts for 65 percent of industry value at USD 601 million while shellfish valued at USD 323 million comprise 35 percent.
Primary cultured shellfish include Pacific cupped oyster, American cupped oyster, hard clam, Manila clam and red swamp crawfish. The red swamp crawfish is the most valuable shellfish crop worth USD 127 million in 2008, followed by hard clam, American cupped oyster, and Pacific cupped oyster worth USD 68 million, USD 45 million, and USD 33 million, respectively. Other cultured shellfish include abalone, whiteleg shrimp and blue mussel. The geoduck clam came into commercial production during the decade, and while production was low at 510 tonnes, the crop is valuable bringing in USD 12 million in 2008.
The graph below shows total aquaculture production in United States of America according to FAO statistics:
The People’s Republic of China is the dominant exporter of seafood to the United States of America supplying 22 percent or 519 348 tonnes in 2008, valued at USD 2.2 billion. Following the People’s Republic of China in volume exports are the Kingdom of Thailand and Canada with 15 and 13 percent, respectively. While Canada’s export volume to the United States of America is 9 percent below that of the People’s Republic of China, the value is slightly higher at USD 2.3 billion reflecting the high value of Canadian products, in particular farmed salmon. Similarly, the Kingdom of Thailand exports 7 percent less seafood volume than the People’s Republic of China, yet earns 14 percent of total revenue compared to the People’s Republic of China’s 15 percent, once again reflecting the relatively high value of the Kingdom of Thailand’s shrimp exports.
With the strong domestic demand for fish and shellfish in the United States of America, export markets for American aquaculture products are comparatively small. The primary export market for fresh catfish fillets is Canada which imported 71 percent of American exports valued at USD 2.1 million in 2008. Other significant importers of fresh catfish fillets are the Kingdom of the Netherlands and the Federal Republic of Germany, at 15 and 8 percent of the market, respectively. Export of frozen catfish fillets is primarily to the Kingdom of the Netherlands at 39 percent, followed by the United Mexican States and the Republic of Italy each with 16 percent. Total export value of frozen catfish fillets is less than USD 1 million.
American trout farmers export primarily to Canada which consumes 67 percent of exported trout valued at USD 1.6 million. Four other countries, Aruba, the Cayman Islands, the People’s Republic of China and the United Mexican States account for another 25 percent of trout exports.
Canada is also the largest market of American farmed oyster exports with 43 percent of market share worth USD 8.9 million. Hong Kong is another primary export market for oysters with market share of 18 percent valued at USD 3.7 million. Seven other countries collectively account for another 28 percent of oyster exports.
To provide an operational framework and support industry expansion, National Aquaculture Policies were adopted by both NOAA and the Department of Commerce in 1998 and 1999. Unfortunately, the rate of growth of the United States of America aquaculture industry projected to 2025 has lagged behind the aggressive targets identified in the DOC Policy (DOC, 1999). At that time, some primary targets were to see production increases of ~10 percent/year, reductions in the USD 9 billion trade deficit in edible seafood, and increased production value from USD 1 billion to USD 5 billion. In the ten years since the policy was adopted the average APR increase has been 1.2 and 1.8 for tonnage and value respectively, the seafood trade deficit has risen to USD 14 billion, and production value is under USD 1 billion/year.
There are a number of reasons for this relatively slow growth rate and they include potential environmental impacts associated with aquaculture and resulting public opposition, user conflicts, multiple state and federal agencies with uncertain and/or conflicting regulatory authority, economic risks, lack of capital, and foreign competition (Cicin-Sain et al., 2001).
In 2004, the United States of America Commission on Ocean Policy stated that NOAA should expand marine aquaculture research, including training, extension, and technology transfer, and set priorities for research and technology development. In concert with that direction, the President’s Ocean Action Plan in 2005 called for submission of legislation to Congress to establish a regulatory structure for offshore aquaculture.
Recognizing the need for further action to accomplish these multiple tasks, and to realize the targets identified in the 1999 DOC Policy, NOAA Fisheries revitalized its Aquaculture Programme in 2004 with a National Marine Aquaculture Initiative, recruitment of an Aquaculture Programme Manager and subsequently filling staff positions in policy, outreach, aquatic animal health, and regulatory affairs, and recruitment of five regional aquaculture coordinators working throughout the country. This NOAA aquaculture team has provided needed momentum to the programme and achieved a number of significant milestones.
In 2007, NOAA completed and adopted the ten-year plan for Marine Aquaculture as an agency-wide policy document (NOAA 2007). The plan is intended to guide the agency as it works towards establishing marine aquaculture as an integral part of America’s seafood industry.
More recently, the Secretary of Commerce and the NOAA aquaculture team hosted a National Marine Aquaculture Summit in 2007, at which national seafood and aquaculture business leaders, policy experts, government officials, non-governmental organizations, and researchers discussed the opportunities and challenges for marine aquaculture in the United States of America. Summit participants agreed on the need for national offshore legislation to provide regulatory certainty for those considering investing in federal waters. They also cited complex and uncertain regulations, lack of a supporting research and development infrastructure, and lack of economic incentives as three major constraints to expanding marine aquaculture.
Building on this progress, NOAA announced its intention to pursue a new National Policy for Sustainable Marine Aquaculture in the United States of America. NOAA Administrator Dr Jane Lubchenko said, “We will develop a national policy that focuses on the protection of ocean resources and marine ecosystems, addresses the fisheries management issues posed by aquaculture, and allows American aquaculture to proceed in a sustainable way.” The national policy will continue NOAA’s work protecting and sustainably using the nation’s coastal and marine resources, while at the same time enabling expansion of a sustainable domestic aquaculture industry. This policy was released in draft form in February 2011.
Along with this policy, a National Aquaculture Act submitted to Congress in 2007 would authorize the Secretary of Commerce to establish and implement a regulatory system for offshore aquaculture in the United States of America’s Exclusive Economic Zone. This bill has not been enacted as legislation.
Private sector associations, often affiliated with states or particular cultured species, contribute significantly to the aquaculture sector. These are more often independent of government agencies but often collaborate in specific areas of mutual interest. It is these private sector associations that often develop voluntary environmental codes of conduct and best management practices to improve industry performance. These codes and practices often follow guidelines found in the FAO Code of Conduct for Responsible Fisheries (FAO 1995).
Over the last decade many initiatives have gained traction to improve the overall outlook for aquaculture development. The Federal Government has taken significant steps to move forward an aquaculture agenda. These include spatial planning that includes aquaculture as an ocean dependent use, progress in identifying organic certification criteria for aquatic animals, a National Aquatic Animal Health Plan, aggregation of aquaculture production statistics, and the national policies and legislation mentioned earlier (NOAA 2008). Nonetheless, many challenges remain.
The Army Corps of Engineers is responsible for issuing permits as it relates to navigation, dredging and fill through their authority under the Rivers and Harbors Act of 1899, Sections 9 and 10, and Section 404 of the Clean Water Act. The Corps evaluates permit applications, and following review as necessary by the Environmental Protection Agency (EPA), the Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) to ensure environmental and resource protection, the Corps issues permits.
The EPA has authority under the 1972 Federal Water Pollution Control Act (FWPCA) Amendments and the 1977 Clean Water Act to issue permits for effluent discharge. Generally, in partnership with state and tribal agencies, EPA accomplishes this through National Pollutant Discharge Elimination System (NPDES) permitting. This permitting system regulates effluent water quality and ensures environmental and natural resource protection against adverse impacts resulting from aquaculture discharges.
The lead agency for protection of aquatic animal health is the USDA Animal and Plant Health Inspection Service (APHIS) responsible for preventing, controlling, and eliminating aquatic animal diseases. Authority of USDA for aquatic animals is found in the Animal Health Protection Act. APHIS works closely with animal health programmes managed by the states for both cultured and wild aquatic organisms. Regulations vary from state to state but most have health protection regulations, field health services, extension specialists, and diagnostic and inspection laboratories to test for diseases and pathogens. The National Marine Fisheries Service under the authority of the National Aquaculture Act is required to develop an aquaculture programme which includes aquaculture fish health management. The Fish and Wildlife Service has authority under the Lacey Act to prohibit the possession or importation of any pathogens deemed to be injurious. Working together, these agencies have developed a comprehensive Aquatic Animal Health Management Plan intended for release in 2011.
The Health and Human Services Food and Drug Administration through the Food, Drug and Cosmetic Act has the responsibility for ensuring that all seafood is safe and wholesome to eat. The United States Food and Drug Administration (FDA) also holds regulatory authority for approval of drugs other than biologics for use on aquatic animals. Environmental safeguards that are part of this approval process are regulated by the National Environmental Policy Act (NEPA). Regulations implementing NEPA consider harm to the environment to include not only toxicity to environmental organisms but also environmental effects other than toxicity, such as lasting effects on ecological community dynamics.
Research priorities are set by individual organizations and agencies and entail broad expert consultation with academics and industry. Collaborative research is encouraged and partnerships with industry on pilot projects are a proven methodology to solve problems and transfer technology. In addition to publication of research results in peer reviewed journals, extension services of USDA and Sea Grant work closely with industry using manuals, fact sheets, workshops and demonstrations to widely disseminate information.
While by no means all-inclusive, the following are some prominent government, private and university institutions offering programmes in aquaculture research education and training.
University and affiliated programmes
The United States of America has an extensive array of universities offering undergraduate and advanced degrees in disciplines related to aquaculture. Some of the larger programmes are at the University of Maine, University of Arkansas, University of Florida, Florida Atlantic University Harbor Branch Oceanographic Institution, Hubbs Sea World Research Institute, Mississippi State University, Louisiana State University, University of Pennsylvania, University of New Hampshire, Virginia Institute of Marine Science, University of Maryland, Auburn University, University of North Carolina, University of Miami’s Rosenstiel School of Marine and Atmospheric Science, Massachusetts Institute of Technology Woods Hole Oceanographic Institution, Virginia Polytechnic Institute and State University, Texas A and M University, University of Arizona, University of California at Davis, University of California San Diego Scripps Institution of Oceanography, University of Rhode Island School of Oceanography, Oregon State University Hatfield Marine Science Center, University of Washington School of Fisheries, and University of Hawaii.
USDA-National Institute of Food and Agriculture, Regional Aquaculture Centers
Center for Tropical and Subtropical Aquaculture
North Central Regional Aquaculture Center
Northeast Regional Aquaculture Center
Southern Regional Aquaculture Center
Western Regional Aquaculture Center
USDA – ARS Research Laboratories
The Agriculture Research Service of USDA maintains aquaculture research centers in Alaska, Alabama, Arkansas, Florida, Hawaii, Idaho, Louisiana, Maine, Mississippi, Oregon West Virginia, and Wisconsin.
USDA Cooperative Extension Service (CES)
CES staff provide for research, education and technology transfer through 74 land grant universities located in all 50 states and six territories.
US DOC NOAA – NMFS
NMFS has 31 Research Science Centers throughout the country. Aquaculture research is a principle focus of the Manchester Laboratory in Washington and the Milford Laboratory in Connecticut.
US DOC NOAA – Sea Grant
The National Sea Grant College Program within NOAA is a federal - state partnership supporting research, extension and communication to improve management of coastal and marine resources. It comprises a network of 30 university partnerships in coastal and Great Lakes States using university research laboratories to support programmes in aquaculture, fisheries and coastal resources.
There is a clear need to expand aquaculture production in the United States of America. The need for additional seafood in the future, offsetting a USD 9 billion trade deficit in imported seafood products, coastal economic development, expanded employment opportunities, increased supplies of safe and sustainable seafood, the reality of fully exploited capture fisheries, and enhanced food security all provide compelling reasons.
It is noted in NOAA’s ten-year plan for Marine Aquaculture that by 2025 American aquaculture production could more than double, adding one million tonnes of production and creating 75 000 new jobs. The additional production could include 760 000 tonnes from finfish aquaculture, 47 000 tonnes from crustacean production, and 245 000 tonnes from mollusc production. Of the 760 000 tonnes of finfish aquaculture, 590 000 tonnes could come from marine finfish aquaculture (Nash, 2004).
In the interest of developing a framework to facilitate this, the United States Department of Commerce and NOAA released the draft Aquaculture Policies in 2011. (US DOC 2011, NOAA 2011). These documents describe a broad ranging programme with four priority areas being: 1) Science and Research; 2) Regulation; 3) Innovation, Partnerships, and Outreach; and 4) International Cooperation (NOAA 2011). The first statement of NOAA’s policy is to “Enable sustainable aquaculture that provides domestic jobs, products, and services and that is in harmony with healthy, productive, and resilient marine ecosystems, compatible with other uses of the marine environment, and consistent with the National Policy for the Stewardship of the Ocean, our coasts, and the Great Lakes”. The regulatory environment that emerges as a result of these policies will determine whether aquaculture production expands to fulfill its potential, or Americans continue to import ever increasing quantities of seafood to meet future demand.
Cicin-Sain, B., Bunsick, S., DeVoe, R., Eichenberg, T., Ewart, J., Halvorson, H., Knecht, R., & Rheault, R. 2001. Development of a Policy Framework for Offshore Marine Aquaculture in the 3-200 Mile U.S. Ocean Zone. Center for the Study of Marine Policy the Sea Grant Technology Program, National Oceanic and Atmospheric Administration
FAO. 1995. Code of Conduct for Responsible Fisheries. Rome, FAO. 1995. 41p.
Forster, J. 2002. One on One. SeaFood Business magazine. ed. Peter Redmayne.
Nash, C.E. 2004. Achieving policy objectives to increase the value of the seafood industry in the United States of America: the technical feasibility and associated constraints. Food Policy 29(6):621–641.
NOAA. 2007. NOAA 10 - Year Plan for Marine Aquaculture. U.S. Department of Commerce National Oceanic and Atmospheric Administration, National Marine Fisheries Service.
NOAA. 2008. National Aquatic Animal Health Plan for the United States of America. National Aquatic Animal Health Task Force. U.S. Department of Commerce National Oceanic and Atmospheric Administration, National Marine Fisheries Service.
NOAA. 2009. Fisheries of the United States – 2009. http://www.st.nmfs.noaa.gov/st1/ Please cite data retrieved from our web site as "Personal communication from the National Marine Fisheries Service, Fisheries Statistics Division, Silver Spring, MD"
NOAA. 2011. Draft Aquaculture Policy.
Tucker, C., Avery, J., Engle, C. & Goodwin, A. 2004. Industry Profile: Pond-Raised Channel Catfish: A review developed for the National Risk Management Feasibility Program for Aquaculture. Mississippi State University, Agreement No. RMA 01-IE-0831-127. 92 pp.
USDA. 1998. 1998 Census of Aquaculture.
USDA. 2005. 2005 Census of Aquaculture.
US DOC. 2011. Draft Aquaculture Policy.