Eight experimental diets were formulated for rainbow trout using agricultural byproducts as major ingredients. Each experimental diet contained varying amounts of corn grain, corn gluten meal, corn gluten feed and one of the following: 200 g kg⁻¹ peanut meal, 200 or 400 g kg⁻¹ soybean meal (SBM), 390 g kg⁻¹ low-allergen soy flour, 310 g kg⁻¹ soy protein concentrate, 300 g kg⁻¹ low-allergen soy protein concentrate or 200 g kg⁻¹ SBM + 110 g kg⁻¹ blood meal. One diet contained 200 g kg⁻¹ SBM and canola oil as the main lipid source. The remaining diets contained 95 g kg⁻¹ menhaden oil. Fish fed a commercial trout diet exhibited significantly greater weight gain (322%), and a lower feed conversion ratio (0.89) but significantly lower protein efficiency ratio (2.18) than fish fed the experimental diets. Within the experimental diets, fish fed the 400 g kg⁻¹ soy flour diet and the 400 g kg⁻¹ soybean meal diet had significantly higher weight gains (276% and 268%) and protein efficiency ratios (2.58 and 2.52), and lower feed conversion ratios (1.02 and 1.03) than fish fed other experimental diets. Fillet flavour varied between treatments. Most notable was the lower fishy flavour and higher chicken flavour of fish fed the diet that contained canola oil rather than menhaden oil. Microscopic evaluation of the liver and five sections of the gastrointestinal tract failed to demonstrate any differences between treatment groups. The ingredient costs of several experimental diets were lower than the estimated cost of a standard commercial trout diet. However, the superior feed conversion ratios of fish fed the control diet resulted in lower feed costs per unit of fish produced.

Aquaculture is not a new concept. Japanese, Chinese, Romans, Egyptians, and Mayan Indians farmed fish for food and recreation prior to 2000 BC. Ponds were constructed and fish were raised much in the same manner as fish are raised today. Both freshwater and saltwater fish are currently raised commercially throughout the world. Other related aquatic products raised commercially are shrimp, crayfish, oysters, clams, worms, crickets, frogs, and some plants. Aquaculture is the general term used to describe the propagation and rearing of aquatic animals and plants in controlled or selected environments. Although aquaculture is increasing in popularity in this country, the vast majority of fisheries food products eaten in the United States are imported or are captured wild stocks from natural waters.

Largemouth bass (Micropterus salmoides) are the most sought-after freshwater sport fish in the United States. Largemouth bass are a member of the family Centrarchidae. Currently the genus Micropterus contains seven species. As part of the development of the new strategic plan, the North Central Regional Aquaculture Center (NCRAC) is trying to address the concern that the long-term focus of research goals and priorities may be lost because the NCRAC Board of Directors (Board) and the Industry Advisory Council memberships change over time. The Board in the June 1999 meeting directed that an updateable white paper be written on largemouth bass. The white paper is not an exhaustive literature review, but a working document that defines the current status of largemouth bass culture including the critical factors limiting the economic production in order to make recommendations for future research. Industry participation and peer reviews are critical components for the evolution of this document.

Salmonids are grown in many states in the North Central Region (NCR) with a major emphasis on rainbow trout production. The North Central Regional Aquaculture Center (NCRAC) Industry Advisory Council (IAC) designated salmonids as a high priority area and research on salmonids has been supported by NCRAC since 1990. Recently concern was raised over the long-term focus of NCRAC funded research and extension activities and at the June 1999 NCRAC Board of Directors (Board) meeting, it was decided that additional white papers should be developed to help strengthen various focus areas. As a result, the Board determined that one of these white papers should be on salmonids. This white paper reviews the current status of the salmonid industry, addresses critical limiting factors and research/outreach needs, and gives recommendations for future research/extension priorities. It should be viewed as a “living document” and updated periodically as new developments occur.

The first topic that must be considered is the name. Crayfish is the term most often used in technical literature and the name used in this document. However, these same animals are also known as crawfish, crawdads, and mudbugs. Rest assured, regardless of the name, they all refer to the same broad category of animals. Specifically, they are freshwater decapod crustaceans, the freshwater equivalent of shrimp and lobsters. In most years, production of crayfish in the United States is the second largest aquacultural industry. This fact surprises most people in the North Central Region (NCR) because the availability of crayfish outside the traditional production area is minimal. Most of the crayfish are produced in the southern United States (Louisiana, Arkansas, Texas and Mississippi) and most of that production is consumed in the same area. Two species comprise the majority of production—the red swamp crayfish (Procambarus clarkii) and the white river crayfish (P. zonangulus). Crayfish culture in those areas is seasonal, available as a fresh product from November through June. Thus, the crayfish aquaculture industry is interesting because of it’s size and the fact that it violates conventional wisdom in several ways.

Baitfish grown in many states in the North Central Region (NCR) contribute significantly to aquaculture in the region. Each year priority research areas are identified by the North Central Regional Aquaculture Center (NCRAC) Industry Advisory Council and presented in consultation with the Technical Committee to the NCRAC Board of Directors. Concern has emanated from among the various NCRAC constituencies that network plans could potentially lose focus over time and not always address the most critical factors limiting the economical and sustainable production of important species in the region. After discussions were held among members of the various committees and the Board at its 1999 annual meeting, it was decided that a white paper should be developed on baitfish. The Board directed that the paper not be an exhaustive literature review, but rather a working document that clearly defines the current status of baitfish aquaculture, critical factors limiting its economical and sustainable commercial production, and recommendations concerning the research that should be considered in future work plans. It is recognized that this will be a “living document” in that priorities may change based on new developments, new problems encountered, or other externalities. Industry participation and peer reviews are critical components of the process.

Technology has improved production of aquaculture products and reduced unit costs such that reasonably dependable supplies of fish and seafood are available to the markets. This study describes current distribution channels at the wholesale and retail levels for farm-raised and wild-caught species in the North Central Region (NCR), and evaluates both buyer attitudes towards farm-raised products and interest in specific species. Suppliers of fish and seafood products are experiencing a growth in consumer demand. United States per capita consumption of edible fish and seafood increased from 12.8 pounds in 1980 to 15.9 pounds in 1989, and is expected to reach more than 20 pounds per capita by the year 2000 (U.S. Department of Commerce 1990). This is attributed to increased average income, changing consumer demographics, and the present wave of health consciousness (Blaylock et al. 1987). As “Baby Boomers” approach middle age and the number of senior citizens increase, the health benefits derived from eating fish are becoming important issues.

Trout have been raised in the United States for about 150 years. Initially, trout were raised to replace wild stocks that were declining because of over fishing, loss of habitat and pollution. United States trout farming began in the North Central Region with the establishment of Ackley’s Farm near Cleveland, OH. This farm was run by Theodatus Garlick, M.D., and H.A. Ackley, M.D., who developed ways to spawn brook trout and incubate the eggs in glass jars. Today, trout are still raised in the North Central Region in state, federal and private fish farms to stock lakes, ponds and streams. Trout are also raised and sold through fee fishing operations and as food fish through restaurants and supermarkets. Rainbow trout are the most commonly raised trout followed by brook and brown trout. Private commercial trout farms range from small owner/operator farms to large farms with many employees.

Walleye, Stitzostedion vitreum, has potential to be an aquaculture species in the North Central Region because:

• it is native to the region;
• it maintains optimum growth at temperatures lower than many other current aquaculture species (such as channel catfish);
• it is a highly-prized sport fish;
• its flesh is considered a delicacy; and
• the fillets are high in protein and . low in fat, making walleye an attractive food selection for today’s health conscious consumer.

The North Central Region (NCR) of the U.S. aquaculture industry is growing and changing. Salmonids (salmon and trout) are among the principal fishes currently cultured in the NCR — the rainbow trout being the number one species produced commercially (NCA-23 1987). Though it is relatively small when compared to the Idaho trout industry, trout farming in the NCR adds significantly to agriculture diversity in the region and to the total national production of trout (NCA-23 1987; WASC 1988). To better assist the salmon and trout producers within the NCR, the North Central Regional Aquaculture Center (NCRAC) has established a Salmonid Research Work Group to initiate new research that will benefit the aquaculture industry. The first Work Group meeting decided that a survey of the trout and salmon producers in the 12-state NCR be initiated to document the volume of production of trout and salmon eggs and fingerlings.