ID

420-010

Authors as Published

As a sportfish grown for stocking recreational waters, rainbows are highly regarded as spectacular fighters and leapers, and for their healthy appearance, color, and table quality. Rainbow trout are native to the western United States, but have been widely transplanted in the eastern states. Self-reproducing populations occur in Virginia's coldwater streams.

However, despite these disadvantages, they are also a good species for farming. Brook trout are considered a more colorful fish, have native species appeal, and often are considered a better eating fish than rainbow trout. As a sportfish, brook trout are not as esteemed as fighters as rainbow trout, but they are much easier to catch and, therefore, would be an excellent choice for stocking in fee-fishing or catch-out pond waters.

Brown trout and other coldwater salmonid species are not recommended for fish farming in Virginia. Although brown trout are commonly reared in state and federal fish hatcheries and are stocked in public waters throughout the state, they are less desirable for farming than rainbow or brook trout.

Brown trout are more territorial, more cannibalistic, more difficult to catch, and often considered a poorer quality food fish than either brook or rainbow trout. Brown trout will grow to a very large size and are tolerant of certain environmental stresses, particularly high water temperatures, but they generally cannot be reared in high densities like rainbow or brook trout. Few private hatcheries rear brown trout and, consequently, eggs, fingerlings, and adult stock are difficult to obtain. Brown trout are native to Europe and were introduced into this country in 1883. Wild, self-reproducing populations occur in some of Virginia's coldwater streams.

Rainbow trout is the leading coldwater food and sportfish farmed in the United States. Private commercial production is estimated at about 48 million pounds annually. Most of these fish are sold for food, but the number of trout marketed for stocking private ponds and streams is increasing each year. An additional 20 million pounds of rainbow trout are produced annually at state and federal hatcheries to stock public fishing waters. Most commercial production of rainbow trout occurs in the western states, primarily Idaho, where an abundance of natural coldwater springs with isothermal 15 degrees C (59 degrees F) water temperatures provide ideal farming conditions for this species. In Virginia, rainbow trout is the major food and sportfish farmed commercially.

Rainbow trout production in the state is estimated at about 500,000 pounds annually. Of this total, about 40% are marketed as food fish and 60% are sold as fingerlings and catchable-sized adults for stocking private recreational waters. In addition, over one million trout are produced at public fish hatcheries in the state and stocked each year into approximately 185 streams in 40 counties of Virginia.

Trout culture in Virginia is restricted to the Ridge and Valley Province (Alleghany and Blue Ridge Mountain Region) where an abundant supply of high-quality, cold, spring water provides good growing conditions. Private commercial trout production in Virginia is based mainly on rainbow trout monoculture (single species). Farming of brook and brown trout is negligible, constituting less than 1% of the total annual production. The predominance of rainbow trout is due largely to the availability of eggs and fingerlings. Although some trout farmers in the state produce their own egg stock, many firms purchase eggs from western hatcheries than specialize in egg production.

The trout farming industry in Virginia consists mainly of well- established, small-scale, family-operated firms. Most trout farmers in the state have been in business for at least 10 years, have a labor force of two full-time and two part-time employees, and have 1.6 acre-feet of raceways with an average flow of 2100 gallons per minute (4.7 cubic feet per second). Commercial trout farms in the state are well managed, producing an average of 16,000 pounds for each cubic foot per second (CFS) of water flow.In comparison, the average annual production of trout farms in the U.S. is about 10,000 pounds per cfs.

Trout are coldwater fish that exhibit optimal growth at water temperatures ranging between 13 and 18 degrees C (55 to 65 degrees F). Trout are very sensitive to water pollutants and require high-quality water. Traditional raceway trout farming requires large quantities of cold water. Thus, the success of trout farming primarily is limited by the abundance of clean, cold water.

Trout farming is an expensive business. The seven major costs are for feed, labor, fish, energy, processing, marketing, and distribution. Satisfying the nutritional requirements of trout is particularly expensive. The cost of trout feed accounts for as much as 55% of the total cost of trout production. Since trout are typically reared at high densities in raceways where natural foods are absent, they must be fed artificial diets. Commercial trout feeds are more expensive than other fish feeds because trout are carnivorous and digest carbohydrates poorly and, therefore, must be fed a nutritionally complete diet. Consequently, artificial trout feeds contain large amounts of animal protein (usually fish meal) which is the most expensive feed ingredient.

Securing financial assistance is also a major problem for prospective trout farmers. The high capital outlay for construction of hatchery facilities, along with the high risk and relatively low rate of return, makes it difficult to obtain a loan for trout farming ventures.

Other problems such as water use and water rights conflicts, obtaining effluent permits, satisfying food and drug standards, controlling disease and parasites, and establishing year-round markets confront trout farmers.

Channel catfish is the most widely farmed food fish and one of the most important warmwater sportfish reared in the United States. This species has a number of desirable characteristics for rearing, including its high quality flesh that consists of firm white meat with few intramuscular bones and mild flavor, high tolerance of water temperature variations, rapid growth at water temperatures above 23 degrees C (74 degrees F), high tolerance of crowding, adaptability to a variety of natural and artificial farming systems, high feed conversion values, well- known growing requirements, and ready availability of eggs, fingerlings, and adult stocks.

As a sportfish, this species apparently does not compete drastically with other warmwater fish species and is widely stocked in bass-bluegill ponds--adding variety to anglers' catches.

Other species of catfish including the yellow bullhead (ICTALURUS NATALIS), brown bullhead (ICTALURUS NEBULOSUS), and flathead catfish (PYLODICTIS OLIVARIS), are not as suitable for farming for a variety of reasons.

Catfish farming is the leading fish farming industry in the United States. Commercial production of food-size catfish totalled about 77 million pounds in 1981. Production and consumption of catfish have increased annually since 1976. Farm- reared catfish now account for about two percent of total U.S. fish consumption.

About 60% of the total crop are marketed as food fish and about 40% are sold to stock private sport-fishing ponds and commercial fee-fishing ponds. Most of the catfish production in the U.S. occurs in the Lower Mississippi Valley where an abundance of water and flat land for pond construction and long growing seasons provide ideal conditions for catfish farming.

In Virginia, there are no commercial catfish farmers producing food fish. Over the past 20 years a number of residents have attempted catfish farming, but have had little success. Major problems associated with developing food catfish farms in Virginia are the relatively short growing season; competition with southern growers; the high costs of suitable land, labor, energy, and fish feed; lack of processing facilities and a well- defined market; and fish kills caused by summer oxygen depletion.

Small-scale catfish farming in Virginia can provide supplemental food and income for small and low income pond owners. However, the potential for large-scale commercial catfish farming directed at food fish production is limited.

In contrast, the potential for raising fingerling (small-sized) and adult catfish for stocking private fishing ponds and fee fishing waters in Virginia appears good. Virginia, with more than 80,000 warmwater ponds and lakes, provides a ready market for catfish for stocking. In addition, the growing popularity of catfish fee fishing ponds and lakes in the state is expected to provide a steady demand and ready market for catchable-sized catfish. During 1980, only two catfish farmers in the state were growing fish for stocking. At this time, about 50,000 fingerlings were produced in-state, but an additional 400,000 fingerlings were imported from out-of-state producers.

Constraints/Problems:

Two major environmental factors adversely affecting the production of channel catfish in Virginia are the length of the growing season and summer oxygen depletion. The growing season for catfish (water temperatures above 23 degrees C or 73 degrees F) in Virginia ranges from about 200 days per year in the Coastal Plain and some Piedmont counties to about 150 days per year in the Mountain Province. Under these conditions, farm-reared catfish reach edible size in two or three years. Stocking larger-sized catfish (6 inches or more in length) would reduce the growing time for harvestable fish to about 9 months, but larger larger fish are much more expensive to purchase than eggs or small fingerlings.

The risk of fish kills is always present in catfish farming. Algae, stimulated by nutrients from uneaten food and fish excreta, may suddenly die. Their decomposition leads to oxygen depletion and fish mortalities. Aeration is one solution to preventing oxygen-related fish kills.

The largemouth bass is probably the most important warmwater sportfish in the United States. About 18 million anglers spend over 300 million days fishing for largemouth bass and sunfish in the U.S. each year. In Virginia, over 700,000 adult and youth anglers fish for this species annually.

To help meet this large and growing public demand, government hatcheries in the U.S. produce and stock into public waters more than 8 million fingerling and adult largemouth bass annually. In many states, including Virginia, fish reared in government hatcheries are stocked only in public waters. Private pond owners must buy fish for stocking from commercial hatcheries.

In Virginia, demand for fingerling and adult largemouth bass for stocking private farm ponds, fishing club waters, golf course ponds, fee-fishing lakes, and for corrective stocking in waters with unbalanced fish populations, is high and exceeds in-state production. Only about 100,000 fingerling bass are produced in commercial hatcheries in the state at present.

Largemouth bass farming is relatively simple. It usually consists of stocking a pond with adults and allowing them to spawn naturally, and then removing the adults or young to prevent cannibalism. Controlling predation and spawning times, producing fertile eggs on demand, training fish to accept artificial feeds or maintaining natural food (usually bait minnows) are the major problems involved with largemouth bass farming.

4. Sunfishes (LEPOMIS spp.) Poor potential (food) Fair potential (stocking)

Sunfishes are generally considered unsuitable for commercial farming as food fish. However, they are very popular sportfish, particularly with children. Thus, sunfish often are farmed to stock recreational fishing waters.

The two most commonly stocked sunfish species are the bluegill(LEPOMIS MACROCHIRUS) and the of "shellcracker" (LEPOMIS MICROLOPHUS). These species are often stocked at high densities.

They add variety to the anglers' catch. The redear is commonly stocked with bluegills since it grows to a larger size, inhabits deeper water, and does not have as high a reproductive rate as the bluegill. A number of other species of sunfish have been used for stocking ponds, but usually with poor results.

In Virginia, at least four commercial growers produce sunfish for sale to pond owners. Annual production averages about 500,000 fingerling sunfish. The major problem associated with sunfish farming involves their high natural reproductive rate. Sunfish spawn readily, producing large numbers of eggs several times during the summer, which often leads to overcrowding and stunting. These unbalanced fish populations provide an opportunity for sunfish farmers to market fish for stocking, since the only realistic solution is to kill all fish in an unbalanced pond by draining and poisoning, and then to restock the pond.

The striped bass is a major food and sport fish on the Atlantic coast of North America. This species thrives in both salt and fresh water, but must spawn in or near fresh water. Construction of the Santee-Cooper Reservoir in South Carolina and Buggs Island Lake in Virginia trapped some of these anadromous (running up rivers to spawn) fish in fresh water. These landlocked stripers subsequently spawned in the tributary streams of the reservoirs, creating excellent sport fisheries.

Currently, about 10 inland reservoirs in the U.S. support naturally reproducing populations of striped bass. An additional 280 inland reservoirs have striped bass fisheries sustained by stocking fingerlings produced at federal and state government hatcheries.

Striped bass is an extremely important sportfish in the United States. About 4 million anglers spend almost 60 million days fishing for striped bass. To meet this growing demand, government hatcheries produce and stock into public waters about 40 million fingerling striped bass annually. At present, only a few private commercial hatcheries are attempting to produce this species for profit.

A strong demand for striped bass to stock into private recreational waters and for human consumption exists. In Virginia, and most other states, no commercial producers are farming striped bass. The Virginia Commission of Game and Inland Fisheries rears about 1 million fingerling striped bass annually for stocking public waters, but these are not available for stocking private waters.

Unavailability of seed stock is the major problem constraining commercial striped bass farming. Other problems include low survival rates, cannibalism, and disease and parasite infection. But the culture requirements are known and the potential for striped bass farming for food and sportfish production is high. The possibilities of "sea ranching" this species in coastal Virginia adds another opportunity.

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Date

May 1, 2009