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Aquaculture: Potential for Small Scale Farmers in California

Small Farm News
January/February 1992

Fred S. Conte, Department of Animal Science, University of California, Davis.
Adapted from an article by Dr. Conte called, California Aquaculture: Growth Keyed to Diversity and Markets. In World Aquaculture 21(3):33-44,1990.

Aquaculture is among the fastest growing segments of American agriculture and is expanding even more rapidly worldwide. Its growing popularity has stimulated interest among potential growers. The level of participation in aquaculture will depend upon a number of factors, the most important being the availability and nature of the water and land resources.

Each aquaculture species has specific biological requirements. Factors such as growth, health, and reproduction are directly influenced by water quality and associated influences of the land and how it is used. Options based on resources may include ornamental, recreational fishing, fee fishing, small- to large- scale commercial production, and integrated aquatic and land farming operations.

California has the most diverse aquaculture industry in the United States. The state's size, combined with its particular geology and topography, provides a multitude of climatic and water conditions suitable for a variety of growing conditions. A summary of the state's aquaculture industry follows.


Oyster culture is the oldest aquaculture industry in California and dates back to the 1850s.

California's oyster growing areas include Humboldt, Drakes, Tomales, Morro, and San Diego Bays, and offshore sites near Santa Barbara. Growing areas include lands leased from the state, navigation districts, municipalities, and public utilities. 'The industry employs a variety of techniques, each designed for particular environmental conditions. Techniques include bottom culture and a variety of off bottom techniques such as rack and line, rack and bag, stake, longline, raft, and tray culture methods.

Oysters are marketed primarily as shucked product in jars and repack containers, and as shellstock for the half-shell trade and the barbecue oyster market. Markets are diversified and include exports to the East Coast states, retail outlets, restaurants, and over-the-counter sales. Medium shellstock sells for between $25-35 per hundred in bulk, for about $5 per dozen in small allotments, and individual oysters sell for between $.25 - .38 each. The industry production for 1988 was over 1.6 million pounds of shucked meat. Nearly one-half of the oyster production is sold as singles, specialty products, and bulk shellstock.


California is unique in the United States as the only state with an established abalone fishery. As the natural fishery declined and market value grew, interest in culturing abalone was inevitable. In the 1960s large financial commitments were made by several privately-financed R&D companies and the state to develop abalone culture technology at hatchery sites along the central coast. These companies are now producing abalone seed for enhancing natural habitats, for other growers internationally, and for gourmet restaurants. There are 15 registered abalone firms in the state; three are producing significant volumes of seed and market animals.

Of the species grown, about 95 percent are red abalone and 5 percent are pink or green abalone. The grow-out phase generally takes place in land-based, tank and raceway systems, or raft and barrel-habitat systems submerged in sheltered marine environments. Hatchery-set abalone are grown in tanks until they are about a third of an inch; they may then be transferred to suspended containers in tanks or raceways or sold as seed. At 20-28 months the kelp-fed, 2 inch "abs" are marketed in gourmet restaurants located primarily on the East and West Coasts of the U.S. and in Hawaii and Japan. In 1989 an excess of 2.6 million seed animals and 315,000 food animals were produced. Seed abalone prices range from about $.25-.35 each, and food abalone prices are about $40 per pound.


Another fast developing segment of the shellfish industry is mussel culture. Mussel farms have been established in Humboldt, Tomales, and San Diego Bays, and off the Santa Barbara coastline. Growout techniques include thinning and harvest of mussels attached to offshore oil structures and tube and bag culture in bay systems. Mussels are sold both wholesale and retail by growers, and wholesale prices range from about $1.40-1.85 per pound. State production increased to over 1.5 million pounds in 1989.

Channel Catfish

California's channel catfish industry is one of the most profitable aquaculture industries in the state. It is based on traditional pond production of channel catfish with some production of the channel catfish x blue catfish cross.

Most production occurs at locations throughout the Central Valley and in the Imperial and Coachella Valleys of southern California. Production is also expanding at geothermal sites in northeastern portions of the state. Catfish are produced on farms ranging in size from 3-400 acres of surface water with production ranging from 1500 to 11,975 pounds per acre.

The state's catfish market structure i s somewhat unique. There is no processing industry, and only a few small processing units for channel catfish exist. Most of the product is sold live, primarily to recreational lakes for fee fishing and to live-tank, foodfish markets. The live haul, foodfish market is relatively new. Market outlets are centered around Asian and Southeast Asian communities in and around large metropolitan centers. Fish are harvested, transported live, and sold to retail outlets with holding tanks in urban areas. Many are then sold live as a fresh product to individual buyers and/or restaurants. Other markets include fry and fingerling sales to other producers, fingerling sales for farm pond stocking, and sale of fresh fish to local restaurants, retail stores, and through farmers markets.

California growers get a premium price for their catfish product. Fingerling sales are about $.04-.05 per inch, and from $1.40-2.00 per pound. The live, foodfish market range for California annual production is about 5 million pounds. Growth is expected in the industry, and specialized processing is in the future.

Rainbow Trout and Salmon

Rainbow trout production is one of the oldest aquaculture industries in California. Production facilities are located throughout the state, primarily in association with artesian springs or the lower discharge water of reservoirs. Production facilities include concrete and soil raceways. Most facilities average production rates of almost 15,000 pounds per 450 gallons of water flow per minute per year.

The rainbow trout industry, like catfish, does little processing. Most trout are marketed through the recreational fee fishing lakes. Some trout, however, are marketed through the live tank, retail outlets and in cooperative planting programs with the State resource agency. Bid contracts with larger recreational lakes range between $1.45-1.75 per pound live weight.

California is also a major trout egg producer with national and international sales. Approximately 80-100 million eggs are moved annually. Other developments now marketed include triploid trout and eggs and all-female eggs.

Another rapidly growing segment of the industry is land-based rearing of coho and chinook salmon and steelhead rainbow trout. Salmon and steelhead eggs are hatched and reared at freshwater sites in northeastern California and are transferred to coastal tank systems. Here they are transitioned to salt water. The steelhead are then grown and sold as whole fish, and the salmon are sold to the 7- to 13 ounce portion market. Growers are also using innovative marketing techniques of shipping smaller salmon to the northwest and buying back larger salmon for finishing before selling to the whole fish market. Several growers are working with Atlantic salmon at land-based facilities, including development of Atlantic salmon broodstock and egg sources.

Baitfish, Ornamental Fish, Crustaceans, and Live Feed

With California's large population and love for recreational fishing and fish-related hobbies, the state's nonfoodfish aquaculture industry is big business. Bait fish production consists primarily of golden shiners and fathead minnows. Production is accomplished in ponds with some fathead minnows produced in polyculture with channel catfish.

California imports a significant number of golden shiners from other states and internally produces about 18-20 million fish annually. Wholesale prices for fish run about $50, $80, and $125 per 1000 for small, medium, and large, respectively. The wholesale price for minnows is about $45 per 1000.

Goldfish, koi-carp, guppies, and aquarium frogs are produced for the aquarium trade and the aquarium feeder-fish industry. The majority of these are used to feed more valuable fish in the aquarium trade. A large segment of this industry, however, produces these same species as ornamental fish in the lucrative world of hobby fish. A single fish may sell for $1.50, or in the case of some ornamental koi, hundreds to thousands of dollars. Annual production of feeder goldfish ranges between $20-32 and $40-60 per 1000 for small and large fish, respectively. Production of these fish takes place throughout California in ponds, tanks, and closed systems.

A major aquaculture industry in the state is production, harvesting, and sale of artemia (small crustaceans) for the aquarium industry and as larval feed for fish and shellfish aquaculture. They are produced in managed, hypersaline evaporation salt ponds at a number of sites located in the San Francisco Bay Area and desert areas in southeastern California. Both the adult and cysts of the ferry shrimp are produced, processed, and packaged for national and international markets. They are a multi-million dollar commodity and among the most valuable aquaculture commodities in the state.

The production of red or black marine worms (tubificid annelids) also provides an important food source for the aquarium trade and fish hobbyists. While much of the worms marketed are obtained from sewage treatment ponds, a substantial amount of the market is supplied by the controlled production of these thread-like worms in pond systems receiving the effluent discharge from aquaculture facilities. Several species are used, most referred to as either red or black worms. The typical production system may be a series of interlinked, shallow ponds or raceway units receiving a portion of the discharge from a trout raceway system. Clumps of worms are harvested, purged to remove gut content, and usually sold to distributors on a profit-shared basis. Distributors buy the worms from producers for about $6-7 per pound. Retail outlets sell the black worms for about $.99-1.09 per ounce in northern California, and both red and black worms sell for about $1 per ounce in the Los Angeles area.

Sturgeon and Striped Bass

Among the fastest growing segments of the finfish industry are sturgeon, striped bass and hybrid striped bass culture. One approach is to diversify the farm by combining the culture of these experimental species with an economically viable species such as channel catfish. This allows shared facilities and resources and year-round activity and markets by separating activities seasonally. A working design incorporates first-use water in intensive tank culture of sturgeon and striped bass, second-use water is then settled and directed to channel catfish ponds, and final-use water is directed toward traditional land agriculture.

Production of these three fish has increased dramatically in recent years. Sturgeon fingerlings are sold to about 40 growers statewide and to markets nationally and internationally. Processed fish of about 12-16 pounds are marketed to white tablecloth restaurants, with total production of foodfish in 1989 exceeding 200,000 pounds. Growers are receiving about $3.50-4-50 per pound live weight.

Striped bass are produced primarily for mitigation of industrial-caused fish loss in the Sacramento Delta. About one million yearling-fish and 0.5 million fingerlings were stocked by commercial growers in 1989. Contract bids for 1989 year-class fish ranged from $1.20-1.60 each for yearling fish and about $.75 each for fingerlings.

Agencies and Support Institutions

California's industry operates under the jurisdiction of a number of State agencies, the primary two being the California Departments of Fish & Game (CDFG) and Health Services. The CDFG is the lead agency. The California Department of Health Services (CDHS) has regulatory authority over all health and sanitation aspects of the shellfish industry, including growing waters, harvesting processing, and shipping of products.

The industry association is the California Aquaculture Association (CAA). The CAA works with agencies and the State Legislature to improve the industry's position in the state. Its members work with state and regional aquaculture funding institutions and researchers to address technical problems and insure an adequate research base for future industry growth.

Dr. Conte is an Extension Aquaculture Specialist in the Department of Animal Science, Univ. of California, Davis (916) 752-7490.

For more information on aquaculture topics such as cannel catfish, state laws, permits, fish pond management, and trout please contact your local county Cooperative Extension office. The county office will work with the UC Davis staff to provide you with available information.

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