Aquaculture Fin Fish Species

Important Aquaculture Fish Species

Revised November, 2018.






Fish species well suited to closed recirculating systems make up what is known in the science as “finfish aquaculture,” these species include: tilapia, hybrid striped bass, barramundi (“Australian sea bass”), yellow perch, sturgeon and eel.  Other species including walleyes, trout, catfish, largemouth bass, koi/carp, shiners, bluegills and sunfish can be raised in these systems, but may be more efficiently and economically produced in outdoor pond systems.  Fish species well suited to outdoor pond systems include: tilapia, yellow perch, walleyes, trout, catfish, largemouth bass, koi/carp, shiners, bluegills and sunfish. Other species including hybrid striped bass can be raised in these systems, but may be more efficiently and economically raised in an indoor recirculating system.


BarramundiBarramundi (Lates calcarifer), commonly known as Asian sea bass, also is known as giant perch, giant sea perch, Australian sea bass, Barra, Barramundi Perch, Bekti, Cockup, Giant Perch, Nairfish, Palmer and by a variety of names in other languages. The name barramundi was originally associated with a different species, derived from a native-Australian name, but was used in a 1980’s marketing campaign and has since become synonymous with Lates calcarifer. Barramundi should not be confused with the sub-Saharan Africa Nile perch, occasionally mislabeled and marketed in some countries as barramundi.

This species is of considerable commercial importance as a recreational sport fish, commercial (wild-harvest) catch and as a large-scale commercial aquaculture species. It is raised in a number of countries on the Indian Ocean rim, as well as by commercial ventures in Israel and Poland. Barramundi is a relatively recent commercial import and aquaculture species in the United States. Within Southeast Asia, it is the largest commercially marketed aquaculture fish, with recent production in excess of 30,000 tons. The U.S. industry produces a mere 800 tons a year from a single facility; an Australian venture, Australis Aquaculture, LLC, Turners Falls, MA. Australia has a well-developed barramundi consumer culture where the fish is highly regarded as a sport- and food-fish.

In the wild, this coastal and estuarine species has an interesting lifecycle. Barramundi is generally classed as a ”catadromous” species, meaning that it lives in fresh water, but moves to inter-tidal zones to spawn. Wild fry feed on the tiny crustaceans and plankton abundant in these ecosystems.

Some lifecycle details make barramundi highly adaptable to commercial aquaculture systems. Older fish can thrive in both purely freshwater or saltwater environments within a temperature range of 26 to 30°C (78.8 to 86°F); most wild fish travel down fresh-water streams where they mate and spawn in brackish (some salt content) estuarine environments.  Brackish water is required for egg fertilization and the successful production of fry.

Barramundi essentially begin life as a hermaphrodite with a distinct male sexual morphology, and may then sex-reverse to an egg-producing female after a single spawning season. Within five years, almost an entire population will exhibit full sex-reversal to females. For this reason, almost all large fish in captivity or wild-caught by sport-fishermen are females. With captive fish there are exceptions, some may not undergo sex-reversion, or conversely, may do so at a smaller size. An Australian government fisheries management report states that hatchery juveniles, between 50 and 100 millimeters in length (~3/16 to 3/8-inch), can be reared to a table size of 400 to 600 grams (14.12 to 21.16 ounces/pounds), within 12 months and to 3.0 kilograms (6.61 pounds), within 18 to 24 months (most U.S. market-average barramundi are between 1.5 to 2.0 pounds).

Most commercial operators purchase fry from dedicated rearing facilities. The fish exhibits a high feed conversion ratio (feed-conversion efficiency), greatly increasing return on investment (ROI) for commercial producers. A Queensland Australia government industry support site reports that the amount of feed required by a fish decreases rapidly with a decrease in water temperature. Maximum intakes occur at 27 to 29°C and decreases to almost zero at 20°C. Feed conversion ratios (total weight of fish produced per total dry weight of feed consumed) of 1.2:1 to 1.8:1 can be expected in well-managed operations at optimum temperatures.

As a food fish, barramundi is an important established species in Indian, Thai, Vietnamese, Malaysian and Australian cuisines. This makes it a potentially important American aquaculture species considering the growing Asian-American population and general American appreciation for Asian, Pacific-Rim or American West-Coast cuisine. Barramundi has firm flesh with large, moist flakes and a sweet, buttery flavor profile. The flesh has only a few bones which are large and easy to remove. Small barramundi have a milder taste than larger barramundi. The skin is also edible and nicely crisps. Barramundi has flesh which is a pearly-pink when raw (Sushi name: Akami) and white when cooked. The fish can be baked, broiled, steamed, poached, grilled or deep fried. Considering that barramundi is very highly regarded and featured in many signature dishes, a well-crafted marketing campaign could easily move fresh American aquaculture fish to white-table restaurants, as well as the fresh-fish counters in major grocery chains.

Considering that barramundi is a very highly regarded and respected species that is featured in many signature dishes across a range of ethnic and contemporary western cuisines, a well-crafted marketing campaign could easily move fresh American aquaculture-produced fish to white-table restaurants, as well as fresh-fish counters in major grocery chains. Additionally, the sustainability issue and position on imported products by the major environmental and consumer-advocate watchdog groups should be a critically positive marketing point, strongly highlighted throughout the distribution-to-end-user value chain for U.S.-produced fish.

Resources / Other links:

Koi / Carp

Koi are ornamental varieties of the common carp. Their natural distribution includes temperate portions of Asia and Europe. Ornamental koi carp are happy in warm water, but they can also tolerate cold winters, and this adaptability has led to their popularity among collectors and water garden enthusiasts throughout many parts of the world, including the United States.  The actual market for ornamental fish in the U.S. is difficult to determine due to the number of hobbyists who sell their product locally to one another and to pet shops. Other sales are targeted nation-wide via the Internet, trade magazines and specialty newsletters. These are very high-value fish and many “sales” are on a cash basis or involve barters.

Nonetheless, juvenile koi are also widely marketed in pet store chains, more or less as a commodity. Water gardening has been one of the fastest growing gardening interests in the U.S. over the past two decades.  As this hobby has grown in popularity, demand for koi and fancy varieties of goldfish has increased rapidly. According to the 2013 Census of Aquaculture, 149 farms in the United States raised koi at that time, with total sales of almost $6.9 million. Florida ranked first in number of farms (25) and total sales ($904,000), while Pennsylvania ranked second in number of farms (14) and California ranked second in total sales ($180,000).

The maximum lifespan of a koi may easily be 20 to 25 years if properly cared for, and one specimen is on record as having lived over 200 years. Although selective breeding of koi originated in China, most of the development of ornamental strains has occurred in Japan during the past 200 years. Most modern techniques for koi production were also developed in Japan, where these varieties are referred to as Nishikigoi, which translates as “brocaded carp.”  Koi enthusiasts recognize a number of breeds or color variations (including 20 major categories), and organized exhibition shows (similar to dog shows) are common in which individual fish are judged best of breed and best of show.  A regional or national champion koi can be worth an enormous sum of money as breeding stock. 

Under culture conditions, between 81°F and 93°F promotes optimal growth for young koi, while 68°F to 82°F is optimal for adults. The pH should remain between 6.8 and 7.5. Although koi are capable of surviving in warm waters with low oxygen, dissolved oxygen levels above 5.0 ppm are optimal.

Spawning commences in early spring as water temperatures approach 63°F. A single female may produce up to 1,000,000 eggs. Breeders generally stock several males with one female, often of similar coloration, in the hopes of generating higher numbers of interesting or prized color combinations.  Koi fry and fingerlings are usually stocked into ponds to be grown to marketable size (anywhere from 1-2 inches to 1-2 feet in length). When the offspring are large enough to evaluate, the vast majority will be culled or sold into the pet trade, while only a few (typically only a few percent) will exhibit coloration worthy of a potential champion.

Depending on the target market (mass production of garden-pond koi, production of high-value fish from champion lines, or some combination of these extremes), a koi production facility can require moderate to high investment.  If little culling is anticipated and fish will be mass produced, typical pond production facilities and methods suitable for regular carp can be adapted.  Selective breeding and maintenance of high-value breeding stock generally relies on a combination of indoor and outdoor pond facilities.  This requires much less land, but a higher investment in buildings and equipment.

Either approach requires significant market research.  Since the end product is live fish, markets must be located within a reasonable distance to allow for safe transport and minimal stress upon delivery.  Many pet stores and discount chains that carry pond-grade koi obtain their stock from large commercial suppliers, and breaking into these high-volume markets can be difficult or impossible. Local garden centers and independent pet shops may be the most logical place for potential producers to begin evaluating markets for their koi.

Koi can be extremely high-value fish, with koi fanciers usually being equated with orchid collectors, dog or horse breeders, and similar specialists. The price differential, which depends on size and breeding condition, between standard-quality pond fish and prized show-quality fish is extreme. A popular U.S. Web site lists prices for individual (small) 3-inch to 4-inch fish at $4.00 to $24.00 and (largest size grade) 23-inch to 24-inch fish at $660 to $3,000. (Fact Sheet, Ashi Fancy Koi.)  Some prize breeders can sell for well over $100,000.
 Resources / Other Links:

  • Aquaculture, Economic Research Service (ERS), USDA.
  • Aquaculture in Hawaii- Hawaii Aquaculture web page, an information source and guide to getting started in aquaculture in Hawaii, presented by the State Aquaculture Development Program, State Department of Agriculture.
  • Aquaculture Resources - National Oceanic and Atmospheric Administration (NOAA), fisheries market news and statistic summaries (aquaculture results by catch), available grants, new marine product food safety guidelines, endangered natural stocks, export guidelines for shipments to the European Union, links and addresses of many National Marine Fisheries Support Offices, and other information. Site includes information on Department of Commerce Aquaculture Policy, the National Aquaculture Act of 1980, recent NOAA Aquaculture Policy and breaking research and legislative news.
  • - An Internet information and resource for aquaculture and fisheries.
  • Census of Aquaculture (2005), National Ag Statistics Service, USDA, 2006.
  • Census of Aquaculture (2012-2013), USDA, 2014.
  • Fact Sheet, Ashi Fancy Koi.
  • Koi Magazine USA - Primary publication resource of Associated Koi Clubs of America, the koi industry and enthusiasts. Site contains a list of links to equipment suppliers, clubs and private individuals.
  • Pond Dynamics/Aquaculture - The Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/A CRSP) represents an international, multi-disciplinary effort to improve human nutrition through pond aquaculture research. The work of the PD/A CRSP benefits both domestic and international aquaculture.
  • State of World Aquaculture 2010, FAO, United Nations.
  • World Aquaculture Society - International society of aquaculturalists working to improve education and communication within the industry.

Salmonsalmon fish

Atlantic salmon (Salmo salar) are distributed across the basin of the North Atlantic Ocean from the Arctic Circle to Portugal in the eastern Atlantic, from Iceland and southern Greenland, and from the Ungava region of northern Quebec south to the Connecticut River. Part of their life cycle occurs in saltwater and part in freshwater. Atlantic salmon were eliminated from most of their native range in the northeastern United States and Canada, but restocking efforts have re-established them in many watersheds.

Atlantic salmon are cultured extensively at state, federal and private facilities throughout the northeast for restoration efforts, recreational fishing opportunities and as a food fish. Under culture conditions, Atlantic salmon eggs should be incubated at 42 degrees F. Upon hatching, the temperature should be dropped to 38 degrees F until the sac fry begins to accept prepared food. At this point, the temperature should be raised to 50 degrees F, then slowly increased to a final maintenance temperature of 60 degrees F. The pH should be greater than 6, and dissolved oxygen levels should remain above 7 ppm.

A group led by an Oregon State University geneticist cautioned that relying on hatcheries to sustain salmon runs is likely to fail in the long run without restoring river habitats. They found that fish raised from wild eggs in hatcheries will soon evolve traits ill-suited to the wild and that hatchery programs "essentially created a fish version of white lab mice." This finding suggests that they are very well adapted to handling, artificial diets and so on but that they do not survive well in the wild.

This has been a controversial issue. Hatchery fish make up about two-thirds of the wild-strain salmon and steelhead (trout) returning each year to the Columbia Basin, the largest producer of salmon on the West Coast. The returns represent just 5 percent of historical levels before dams, logging and other habitat degradation reduced populations and spawning-bed resources. Conservation groups, Indian tribes, fishermen, state and federal agencies, the timber industry, agricultural groups and property rights groups have been battling over the role of hatcheries and the role of artificial population enhancement for decades.

The bottom line: research confirms that steelhead raised for generations in hatcheries do poorly when they try to reproduce in the wild, but the first generation of fish raised from wild parents in hatcheries are as successful at reproducing in their native rivers as their wild cousins. This finding means that hatcheries can use wild-recovered stock for their breeding programs, supplementing their efforts to sustain or enhance the wild-fish resource, and that “aquaculture-strain” salmon are just that, a domestic animal well suited to confinement rearing. These results parallel other studies showing that even hatchery fish bred from wild eggs are inferior to wild-produced fish. This implies that there are three distinct courses for salmon resource protection: habitat restoration for wild fish, augmentation of the wild resource with “first-generation hatchery fish and use of “confinement-acclimated” strains for dedicated aquaculture production systems.

The volume of exported Atlantic salmon is far less than that of Pacific salmon. Likewise, the volume of fresh exported salmon is far less than that of frozen exported salmon. In 2011, however, the volume of exported frozen Atlantic salmon and of exported fresh and frozen Pacific salmon continued to increase.

The largest markets for U.S. fresh and frozen salmon were China and Japan, followed by Canada. During 2017, exports to China and Japan both increased, while exports to Canada decreased. The largest buyers of U.S. canned salmon were Canada and the United Kingdom. Exports to both countries rose by nearly 50% in 2017. During 2011, the United States re-exported 929 tons of salmon valued at $4.9 million (FAS 2018).

During 2017, imports of fresh, frozen, and filleted salmon totaled 659,622 tons and were valued at $3.1 billion, a 6.1 percent increase in volume and a 15 percent increase in value from 2016 (NMFS 2018). Atlantic salmon imports totaled nearly 399.5 million pounds in 2011, increasing from the previous year but still below earlier years. Most imported Atlantic salmon was fileted rather than fresh or frozen. Chile was the largest supplier of fresh Atlantic salmon (ERS). According to USDA's FAS, Chile and Canada were the largest suppliers of salmon, followed by Norway and the Faroe Islands. (FAS 2018).

Resources / Other Links:

  • Aquaculture, Economic Research Service (ERS), USDA.
  • Aquatic Network - Aquaculture topics, educational information, publications and products and services listing. 
  • Aquaculture Program, National Oceanic and Atmospheric Administration (NOAA) - Fisheries market news and statistic summaries (aquaculture results by catch, available grants, new marine product food safety guidelines, endangered natural stocks, export guidelines for shipments to the European Union, links and addresses of many National Marine Fisheries Support Offices and other information.
  • Atlantic Salmon, Fisheries and Aquaculture Department, FAO, UN, 2004.
  • Census of Aquaculture (2005), USDA, 2006.
  • Census of Aquaculture (2012-2013), USDA, 2014.
  • Farmed Salmon, Agriculture and Agri-Food Canada, Ottawa, Ontario.
  • Global Aquaculture Production, Food and Agriculture Organization (FAO), United Nations (UN), 2010.
  • Global Agricultural Trade System (GATS), Foreign Ag Service (FAS), USDA.
  • Import and Exports of Fishery Products 2011, Fisheries Statistics Division, NMFS, 2012.
  • National Aquaculture Association - This producer-based association is dedicated to the establishment of national programs that further the common interest of individual producers and members of the aquaculture industry.
  • Salmon Fisheries in Alaska, Alaska Department of Fish and Game - Site includes permit information, overviews of state production and related information.
  • Salmon Market Report, Globefish, FAO, UN, February 2012.
  • Top 10 Consumed Seafood, National Fisheries Institute,, 2016 - Lists the top ten species consumed in the United States by pounds per person.

Tilapiatilapia cut

Tilapia (til ah pe ah), is the second most important group of farmed fish after carp and the most widely grown of any farmed fish on the planet. It is farmed in at least 85 countries, with most imports coming from Asia (China and Indonesia) and Latin America (Honduras, Ecuador and Costa Rica).

The global supply of farmed tilapia surged in the 1990s and early 2000s, largely due to the widespread introduction of improved tilapia breeds, increased feed availability, the effective management of reproduction through sex reversal and hybridization, and expansion of consumer markets throughout the world.

According to the National Fisheries Institute, tilapia now ranks fourth on its “Top Ten” list of the most consumed fish and seafood in the United States. During 2017, the average consumption of tilapia was nearly 1.18 pounds, down from 1.5 pounds per person the previous year. In 2012 the FAO World Aquaculture production principal species report listed world Nile Tilapia (Oriochromis niloticus) production at 3,197,330 metric tons valued at $5,260,695,000 USD. When related species are included with Nile tilapia, world production is estimated at 4,507,000 metric tons valued at $1,699/metric ton.

Tilapia are hardy and prolific fast-growing tropical fish. They can live more than 10 years and reach a weight of over 10 pounds, but depending on environmental conditions some species can reach maturity at less than a quarter of a pound. Although tilapia can live in either fresh or salt water, most species are unable to survive at temperatures below 50°F.

Currently, tilapia are produced in the United States in outdoor ponds as well as indoor systems for sale as live food fish to the restaurant and supermarket trade. In most areas of the southern U.S., tilapia production in outside facilities is strictly regulated to avoid unwanted introductions and environmental damage to native fresh-water systems, particularly to sport-fishing resources.

Under culture conditions, brood stock are held onsite and spawned to produce eggs. Under ideal conditions, females may spawn every seventeen days. The eggs and resulting fry are maintained at a temperature of 80°F to 84°F. The pH is maintained at 7.5 to 7.8, while dissolved oxygen levels should remain at or above 8.0 ppm. Under these conditions, market-sized fish can be obtained in about seven to ten months depending on stocking density.

Within the past few years there has been an increase in water-circulating closed-system tank production of tilapia in aquaculture or aquaponic systems. Tilapia is a particularly good candidate for aquaponics where the toxic nitrogenous waste of the fish is converted to plant-usable nitrogen using biofilters. Plant uptake of this fertilized water then removes the remaining nitrogen content and the clean water is returned to the fish tank. Aquaponics can produce both fish protein and plants in a very confined or limited space. Since tilapia have a very efficient feed-to-protein feed-conversion ratio, grow very quickly and can be “crowed” in very high populations within the fish-tank part of the system, they are one of the best candidates for aquaponic production. Brood stock and hobbyist and classroom to commercial-production off-the-shelf systems are available from a number of suppliers.

As of 2013 (the last Census of Aquaculture conducted by the USDA), 181 farms in the United States cultured tilapia, reporting total sales of $42.5 million. Most of this production reaches the market as a live product destined for Asian and Hispanic consumers. While the largest number of tilapia farms were located in Florida (45 farms) and Hawaii (16 farms), Alabama (11 farms) and Arizona tied for first in sales both with just over $4.7 million. 

Of these farms, the largest number (139) reared foodsize tilapia, reporting total sales of $40 million. Other tilapia farms specialized in fingerlings, fry and broodstock (NASS 2014). The industry still fits this general profile today, but the number of smaller recirculating-system based operations in the Midwest and Northeast has declined due to significant cost increases for feed, as well as competition from larger producers, who can generally sell at reduced prices due to economies of scale.

Growth in production appeared to be accelerating at that time. The total reported value of global tilapia production increased from $203 million in 1985 to $5.7 billion in 2010, reflecting not only the staggering growth in volume of production but also an increase in (world-wide) pond-bank value from $0.44 to $0.74 per pound. Of course, the bulk of this production involves smaller fish for local or regional markets, but large fish destined for global fillet markets in the United States, Europe and Asia can command as much as $1.50 per pound at harvest, and live tilapia have been valued at $3 per pound or more in the United States and Europe in recent years. By 2015, world production is forecast to reach 4.6 – 5.0 million MT (FAO 2010).

In a University of Florida operational analysis, a model business analysis suggested that a small-scale, outdoor pond tilapia culture facility could be profitable. Positive average annual net returns and a cash flow that is positive throughout a five-year planning horizon supported this conclusion. Given the assumptions concerning yield, harvest size, market prices and per-unit input costs, the hypothetical six-acre tilapia culture facility required an initial investment of $65,850 and generated $40,259 in annual operating costs, yielding $29,221 in net returns during an average year. However, variables including market price, feed costs, survival rates, technical ability, geographic location of the facility, prevailing market conditions and additional factors including other input prices and stocking densities were also shown to potentially influence profits. Given the increase in feed costs over the past decade, productivity would have to improve for this model facility to maintain profitability.

Lutz (2000) examined the comparative production costs of U.S. tilapia operations (open ponds, greenhouse facilities and enclosed indoor tank systems) with those of tropical production facilities and concluded that improved strains and technology would be required to allow for competition in domestic fillet markets. These advances have not been forthcoming, and production costs have increased over the past decade. With the availability of frozen tilapia imports from China, almost all of the tilapia cultured in the United States is sold as a live product to attract the premium price necessary to cover production costs. This situation is not expected to change in the foreseeable future. Producers in the United States must focus on developing markets for live products, improving management and technology for recirculating aquaculture production, and managing procurement (fingerlings and feed) and inventory aspects of their operations.

The U.S. tilapia import market is split into the frozen and the fresh segments. Frozen fillet volume continues growing strongly, while whole frozen product has remained fairly constant due to a limited market. In 2017, primary suppliers of frozen fillets to the United States were China ($426.5 million) and Colombia ($48.2 million). China ($40.4 million) and Taiwan ($17.6 million) account for almost all imports of frozen whole fish. When production declines in China and Taiwan occur due to unseasonably cold winter temperatures or problems with disease outbreaks, frozen product supplies to North American markets are reduced, and prices generally increase accordingly.

The fresh fillet sector, dominated by Latin American countries, is still experiencing growth in demand, especially from restaurants and supermarkets. In 2010, Honduras surpassed Ecuador as the primary supplier of imported fresh tilapia fillets, in spite of the temporary idling of its second largest operation. In 2017, major suppliers of fresh fillets to U.S. markets included Honduras ($44.9 million), Costa Rica ($30.1 million) and Colombia ($18 million). (ERS 2018)

The popularity of tilapia in the United States remained unaffected during the economic recession although overall consumption of fish products fell by 1.3 percent in 2009. For tilapia, however, consumption increased slightly. As quality controls (off-flavor management) become stricter in major exporting countries, market share for tilapia will probably increase even further in the U.S. However, tilapia is becoming increasingly popular in many European countries, and some portion of the supply traditionally destined for the United States may be diverted in the future to Europe and other markets.

Imports of tilapia products have become a mainstay in the U.S. foodservice and restaurant sectors, where the reasonably priced, mild fish has provided an easy way to add a seafood item to menus. The questions for the U.S. tilapia industry are how best to avoid competing with growing foreign production and how to determine which market segments are most favorable for domestic producers supplying live, locally grown product.

Resources / Other Links:

Brook, Brown, and Rainbow Trouttrout

Brook trout (Salvelinus fontinalis) have a distribution that includes northeastern North America from the Atlantic seaboard south to Cape Cod, the Appalachian Mountains southward to Georgia, west in the upper Mississippi and Great Lakes drainage to Minnesota and north to Hudson Bay. Their natural range has been greatly expanded through artificial propagation.

Brook trout are raised in large quantities by state facilities for stocking into public lakes and streams. They also are cultured in private facilities for both recreational fishing on site and for stocking into private ponds. Additionally they are used by the supermarket and restaurant trade as a food fish. Under culture conditions, brook trout should be maintained at a temperature of about 59°F for optimal growth. The pH should remain close to neutral with an acceptable range of 6.7 to 8.2. As with most salmonid species, dissolved oxygen levels should remain above 5.0 ppm. Generally brook trout spawn before brown trout.

The distribution of brown trout (Salmo trutta) includes Iceland, the British Isles and the Eurasian mainland from Cape Kanin to the Aral Sea and Afghanistan westward throughout Europe. As one of the world’s premier sport fish, brown trout have been widely introduced into many parts of the world. As a result of stocking beginning in the late 1800s, they have been widely established throughout North America.

Brown trout are cultured in large numbers in state facilities for stocking into public waters. Culture also occurs in private facilities mainly for recreational fishing on site and for stocking into private ponds. Under culture conditions, the optimal temperature range for embryo development is 41°F to 55°F. For adults, a temperature range of 54°F to 66°F should be maintained. The pH should remain between 6.8 and 7.8, while dissolved oxygen levels should be above 5.0 ppm.

The habitat requirements for brown trout are essentially the same as those for brook trout. The two frequently coexist, with brown trout slightly more tolerant of higher water temperatures. They have been found to survive in waters as high as 80°F. The diet of young brown trout consists of a wide variety of aquatic and terrestrial insects, their larvae as well as fish and other vertebrates. Larger fish feed mainly during the twilight and nighttime hours with fish and crayfish playing a much more important role in their diet. Brown trout spawn in late autumn to early winter as water temperatures approach 45°F. Natural spawning habitat is essentially the same as for brook trout, namely, shallow gravelly headwaters.

Rainbow trout are one of the most popular and easily reared aquaculture fish. They are a fast-growing and crowding-tolerant fish, making them well suited to captive breeding. These trout are widely used around the world for fish farming and restocking of angling fisheries. The freshwater forms feed on invertebrates and fish, but reared strains do very well on grain-based artificial diets.

Rainbow trout in common use today come from domestic strains developed to suit intensive fish farming as a food fish for sale as a fresh, fresh-frozen or smoked product to restaurants, supermarkets or consumers. When used for aquaculture meat production, the fish are purchased as fry and reared to marketable size, or are hatched onsite in tanks from eggs and sperm obtained from brood stock. When reared for angling, most are stocked at a harvestable size for rapid removal either to public waters or private ponds. Stocking densities and average weights are dictated by the economics of the angling demand. Due to the widespread use of all-female or sterile triploid strains, spawning is uncommon or nonexistent in some commercial (sterile-hybrid) strains. The diet of young trout consists of a variety of aquatic and terrestrial insects and their larvae as well as fish and other vertebrates. Like all trout, rainbow trout do best in cold, well-oxygenated waters. Like brown trout, however, they are much more tolerant of warmer temperatures than brook trout. They are capable of surviving in waters as high as 85°F, provided the water remains well aerated. Spawning begins in early spring as water temperatures approach 50°F. Eggs numbers may be as high as 12,000 per female. For optimal growth, temperatures should be maintained at about 59°F. The pH should remain close to neutral, with an acceptable range of 6.7 to 8.2. Like most salmonid species, dissolved oxygen levels should remain above 5.0 ppm.

USDA National Agricultural Statistics Service (NASS 2014) reported that 359 trout-rearing farms were located in the United States in 2013. Fish sales that year totaled $110.2 million, an increase of 30 percent from the previous year. Idaho recorded $45.2 million in trout sales, the highest total of any state, which accounted for about 50 percent of U.S. sales. California ranked second with $6.89 million in trout sales, followed very closely by North Carolina with $6.2 million and Pennsylvania with $5.3 million.

The value of all sales, both fish and eggs, received by U.S. trout growers during 2011 totaled $85.3 million. Egg sales alone totaled $8.7 million. The major sales outlets for trout 12 inches or longer were sold to processors, which made up 48 percent. The major sales outlets for 6- to 12-inch trout were to recreational sotcking, which accounted for 54 percent of total sales, and to governmental agencies, which accounted for 13 percent. Trout distributed by state and Federal hatcheries in 2010 for restoration, conservation and recreational purposes included 7.8 million 12-inch or longer fish, 59.4 million 6- to 12- inch fish and 74.4 million fingerlings. The estimated value of the fish distributed that year was $100.5 million, down 4 percent from 2010 (NASS 2012).

The products of trout culture include food products sold in supermarkets and other retail outlets, live fish for the restocking of rivers and lakes for recreational game fisheries, and products from hatcheries whose eggs and juveniles are sold to other farms. Food market fish size can be reached in 9 months, but 'pan-sized' fish, around 1 pound, are harvested after 12 to 18 months. Optimal harvest size in the United States is generally 1.5 pounds. Trout are marketed as fresh or frozen whole fish or fillets (often boneless) and as value-added products, such as smoked trout.

As with any business, trout farms aim to increase revenue and reduce expenditure by using the best value feed/seed and materials and by achieving an efficient FCR. The average cost of production is between $2.65 and $4.41 per pound. Running costs can start at $100 per 1,000 fry purchased at 2 to 3 inches and feed for one year from $1,000 to $1,400. Veterinary and medicine costs are from $50 per ton with transportation and sales commission about $500 per ton (FAO 2003).

In 2017 the value of trout imports jumped by 59 percent, reaching $136.4 million. About 90 percent of the imported trout comes from Chile and Norway.Trout exports from the United States are small. However, the value of trout exports increased 40 percent during 2017, reaching just under $10.5 million. Canada continued to be the largest market for U.S. trout; the country purchased fish valued at $6.6 million (FAS).

Resources / Other Links:

  • Aquaculture, Economic Research Service (ERS), USDA.
  • Bullfrog Fish Farm, Menomonie, Wisconsin - Herby Radmann built a small profitable fish farm from scratch. He sells thousands of pounds of rainbow trout each year to farm visitors,restaurants and retail outlets
  • Census of Aquaculture (2005), USDA, 2006.
  • Census of Aquaculture (2012-2013), USDA, 2014.
  • Century Trout Farm, Oregon, Wisconsin - This fee-fishing enterprise has a website with photos of the resources and an FAQ section that covers topics including group availability, fish species, pricing, disabled angler provisions and various services.
  • Import & Export Data, USDA, FAS. 2018.
  • Farmed Rainbow Trout fact sheet, Agriculture and Agri-Food Canada, Ottawa, Ontario.
  • Heartland Fish Cooperative, Ag Marketing Resource Center, Iowa State University, 2003 - Business profile on Iowa aquaculture operation. The cooperative has four family producer-owners with indoor, enclosed aquaculture facilities at two locations. They produce "fresh-frozen" fresh-dressed, wrapped and frozen rainbow trout and walleye pike fillets.
  • Imports and Exports of Fishery Products: Annual Summary, Fisheries Statistics Division, National Marine Fisheries Service (NMFS), 2016.
  • Rainbow Trout Cultured Aquatic Species Fact Sheet, Fisheries Global Information System, Food and Ag Organization (FAO), 2003.
  • Rainbow Trout Farm, Sandy, Oregon - This youth- and family-oriented enterprise has 30 acres of trees and meadows and ten landscaped fishing holes stocked with rainbow trout.
  • Trout, North Carolina State University Aquaculture Extension.
  • Trout, Southern Regional Aquaculture Center, Texas A&M University.
  • Trout Production, National Ag Statistics Service, USDA, 2011.
  • United States Trout Farmers Association - USTFA is the oldest commercial aquaculture trade organization in the United States. It now has members in nearly every state. 
  • Wilderness Springs Trout Farm, New London, Wisconsin - In its 30 ponds and concrete raceways, this trout production operation hatches 300,000 rainbow trout per year. It generates revenue more or less equally from public “fee” fishing and the production of fish for pond stocking and sport shows