The USDA National Agricultural Statistics Service (Virginia Field Office) is preparing to conduct a statewide aquaculture survey in the spring of 2009. This survey will reference the 2008 production year and measure changes in size and scope of the industry since the last state aquaculture survey was conducted in 2003. The survey is conducted once every five years and the information helps with legislative, regulatory and marketing decisions at the state level. The distribution of the survey to producers will begin in late December to early January with a deadline set for the spring of 2009. To participate in the survey, or to request a copy of the 2003 survey report, contact: Herman Ellison, State Director 1-800-772-0670; nass-va@nass.usda.gov.

(April, 2008) Virginia State University research has shown that small-scale caged fish culture production in ponds is practical and biologically feasible. Uses of fish harvested from cages include: personal consumption, stocking of ponds, and food fish sales. Primary species for cage culture are rainbow trout, channel catfish, and bluegill sunfishes and their hybrids. Various combinations of the above fishes with companion species are also possible. Other species may be cage cultured or held temporarily in cages under certain situations or for special applications. Poor candidates for cage culture include brown trout, striped bass, hybrid striped bass, largemouth bass, and large pond-reared catfish. Tilapia is a good fish for cage production in ponds; however, in Virginia, tilapia must be reared in closed systems and the producer must be permitted by VDGIF.

Climatic conditions in Virginia’s Central Piedmont and Coastal Plains Regions are well suited for two distinct production seasons. Research, industry results, and over 40 years of experience with caged fish culture shows that double cropping of warm season fish with winter rainbow trout production is a viable option for small producers using farm ponds. Channel catfish, sunfishes, and koi carp are the preferred fishes for spring to fall (warm season) production, and rainbow trout, golden trout and, in some cases, brook trout, are the best choices for fall to spring (winter season) production. Overlaps in fish crops (either during spring or fall seasonal transition times) may occur but seldom create major problems. Seasonal fish production is similar to grain crops as with soybeans and wheat production cycles (basically frost to frost seasons). In ponds where only one fish crop may be practical (due to pond size, fertility, watershed, etc.), then rainbow trout is the preferred species. In small, multi-use ponds, winter production of trout would be the best choice since this would reduce conflicts with other uses (irrigation) and result in fewer adverse effects on caged fish.

Trout averaging four to five fish per pound are stocked in the fall and harvested the following spring. The best trout growth is obtained when fish are fed a quality floating (slow-sink) feed of the proper size. Initially, trout should be fed 1/8-inch (3 mm) size pellets because the 3/16-inch pellets are too large for stocker size trout. The shift to larger size pellets may not be necessary until mid-winter or early spring, thus feed purchases should be planned accordingly. Remember, water temperature (ideal trout range is 55 to 65 Fahrenheit) is the primary environmental factor in fish production and this is true regardless of fish species or season of the year. Trout harvested in late spring must be dressed or sold on ice because live trout stockings/transfers are not possible due to warm water conditions. All sizes of trout are marketable. The most desirable harvest size for trout as food fish is 14 to 15 ounces.

Present recommendations regarding winter cage culture in Virginia include the following. Brook trout can be stocked in the same cage with rainbow trout at the ratio of 1 brook trout for each 10 rainbow trout. Because they feed at cooler water temperatures, brook trout may stimulate rainbow trout to feed more often during the colder winter months. Secondly, brook trout may be reared in cages for either specialty restaurant sales, which can command a higher sales price because they are native to Virginia and are the official state fish, or for live fish sales for fee fishing and sporting club stockings. Thirdly, small rainbow trout usually less than 8 inches total length may be legally sold for recreational fishing bait. Finally, golden trout is an interesting species to produce. Though considered a separate species, for culture purposes it is basically a color variation of rainbow trout. Golden trout are considered by the author to be a novelty fish used mainly in fee fishing operations because for pond or cage culture situations. The lighter color of golden trout is simultaneously an advantage and a disadvantage. Observing them during feeding is much easier for the farmer, but it also causes golden trout to be a prime target of predators, mainly the great blue heron. In all cases, regardless of species, sales of live trout should be made during early spring due to intolerance of handling and transporting at warmer water temperatures.

The warm growing season for cage culture in Virginia is typically from the frost-free spring to fall frost period, or April through October. Catfish stocked into cages should be healthy fish that average 8 to 10 fish per pound. Feeding should be daily with attention given to summer heat and storm conditions. Feeding should be reduced or temporarily stopped when signs of possible low oxygen conditions are suspected. Emergency management measures, especially pertaining to aeration, must be considered and plans made in advance for cage culture in farm ponds. At harvest, caged catfish should average over a half pound and some will reach one pound by fall. However, at harvest, there will likely be a range of fish sizes to be dealt with from both production and sales perspectives. Management options for smaller fish include either over-winter feeding for spring sales or fall sales of fish over 8 inches for live stocking into farm ponds.

A solid business reason that Virginia farmers should consider for growing catfish in cages is to sell them live for stocking farm ponds. Fish too small for food sales may be as valuable, or more so, when sold for farm pond stocking. Charges may be made for the fish and for delivery service as well. Since a two pound largemouth bass can consume an 8-inch catfish, stocking of smaller size fish in older ponds is not recommended. On the other hand, stocking of catfish weighing one-half pound or more also produces “immediate fishing opportunities”.

Other warm-season caged culture opportunities include fish species that are generally sold live for stocking ponds or water gardens for recreational purposes. Bluegill and hybrid sunfishes do well in cages, but they must be fed pellets of the appropriate sizes and should be disturbed as little as possible to reduce mortalities. For short-term sales, koi carp, goldfish, and several other species may be held in cages. Large catfish (over one-half pound) that have been pond reared should not be placed into cages for short-term holding nor for further grow out because they will fight and cannibalize each other. There may be certain situations whereby some cool-season fishes, such as hybrid striped bass and yellow perch, may be reared in cages, but production risks are higher for these species. Some fish require greater experience and advanced management practices to generate successful crops. For culture purposes, cage mesh size, and perhaps shape, should be considered for different fish species and/or sizes.

Farm ponds may provide opportunities to supplement small farm incomes and to enhance the rural lifestyle. More opportunities for farm-raised fish products may arise as consumer interest in locally produced products and emphasis on freshness and wholesomeness, etc. continues to increase. However, farm pond owners’ expectations should not exceed the reality of the actual production capacity of small multiple-use, watershed farm ponds. In summary, many, but not all, Virginia farm ponds are suitable for caged fish aquaculture and the species chosen for production should match existing pond conditions and farmer knowledge, experience, and related capabilities (physical and fiscal).

(February, 2008) In order to maximize efficiency of project funds and to continue to provide fish farming information to industry, studies are conducted with trout during the fall to spring season in VSU ponds. Also, we usually conduct winter studies with catfish left from previous summer season experiments. It was established many years ago that the Central Piedmont and Coastal Plains regions of Virginia are well suited for two seasons of caged fish production in farm ponds. Channel catfish may be reared from spring to fall and rainbow trout may be reared from fall to spring. With experience and management, two crops may be reared in larger size ponds, while ponds less than 2-acres may only allow for the annual production of one of the two species. In smaller ponds, caged rainbow trout during winter would be the best option, with possibly channel catfish loose in the pond for recreational fishing or harvests.

During the 2007 fall to 2008 spring season, we have three cages of brown trout being reared alongside rainbow trout in a comparison trial. Fish stocked this past fall were slightly larger than normally recommended for several reasons. Less feed may be required to grow fish to an acceptable food market size. And, brown trout grow to such a large adult size, their period of fastest growth does not occur in fish less than two pounds.

This is our second attempt to cage rear brown trout because they failed to survive during the first attempt. Brown trout grown in cages in Nottoway County during the early 1990s died during April when water temperatures began to fluctuate. During several seasons since, some brown trout mixed with rainbow trout were observed to survive and grow well. However, market sales of brown trout should be explored beyond live sales to fee fishing operations. Brown trout may not be stocked in public streams or waters managed by VDGIF without a written permit, because brown trout are predaceous upon other trout, especially native brook trout.