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.

Whirling disease is the common name for an infection in salmonids caused by the protozoan, Myxobolus cerebralis. Diseased fish usually show signs of circular swimming, hence the disease name “whirling.” In addition, diseased fish may show other signs, such as black tail, skeletal deformities, and shortened gill cover. Because of the erratic, uncontrolled circular swimming, the fish are unable to eat or escape predators. Myxobolus cerebralis has a two-host life cycle, alternating between salmonid fish species and a benthic organism, the worm, Tubifex tubifex. The worms live in the mud of streams. As many as 10,000 worms can be found in one square yard of a muddy river bottom.

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.

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.

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.

Fish diseases are not new to aquaculture; they continue to be one of the greatest causes of economic loss for the industry. Each year in the U.S., millions of dollars in losses to fish producers are attributed to infectious diseases. The impact from diseases may occur as direct losses due to illness or mortalities as well the indirect effects such as decreased production (e.g., reduced growth rates, feed conversion efficiency, or product quality) or loss of business or reputation.

The hornyhead chub (Nocomis biguttatus) is one of the most valuable baitfish species in Minnesota. Culturing hornyhead chub supplies valuable baitfish to anglers and generates income for fish farmers and baitshop owners in Minnesota and other northern states. Hornyhead chubs can be reared in aquaculture facilities and sold through baitshops to anglers, who are often willing to pay $5 to $6 per dozen. Because it is illegal to import baitfish into Minnesota, such prices put harvesting pressure on wild populations. Culturing hornyhead chubs relieves pressure on wild populations while keeping the market adequately supplied with this desirable bait. This technical bulletin describes how to spawn and grow hornyhead chubs produced in an outdoor spawning system and an indoor over-winter growout facility.

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.