Pond Management: Fish Stocking
Most Virginia ponds only support warmwater fish species like largemouth bass, bluegill, redear sunfish and channel catfish year round. Trout require cold water temperatures (less than 70° F) and high oxygen levels. Many warmwater pond owners across the Commonwealth are enjoying seasonal trout fishing by stocking catchables in October and harvesting them out before the onset of hot weather. Unless trout can find a cool refuge in a pond during the summertime, they are likely to die.
Except for supplemental stocking of channel catfish, a pond that already contains fish generally does not need to be stocked. Only stock additional largemouth bass or sunfish after evaluating the size and numbers of fish you are catching from the pond and some seining in the pond (see Managing Fish Populations). The following information is for new ponds without an existing fish population.
Moving fish from your neighbor's pond or a local lake to your pond is not recommended. Many sunfish species are similar in appearance. You could mistakenly stock sunfish that are not desirable in small ponds. Also, there is a good possibility of transmitting fish diseases from pond to pond. To reduce the risk of stocking undesirable fish species or diseased fish, purchase your fish from a reputable hatchery. See this list of commercial hatcheries (PDF).
Fish to Stock
This fish is best recognized by its large mouth and dark stripe or blotches along its sides. Young bass feed on zooplankton (microscopic animals) and insects until they are 2 to 3 inches long, when they switch to a fish diet. Adult bass usually eat fish, but they will also eat insects, frogs, and crayfish. In Virginia, bass should be 12 inches long in 2 to 3 years. Bass spawn once each spring when water temperatures reach 60-65° F.
Bluegill (bream) are recognized by their small head and mouth, black spot at the base of the dorsal (back) fin, and plain black gill flap. Bluegills prefer to eat insects, but they sometimes eat small fish. Their rate of growth depends on the amount of food available and the number of sunfish in the pond. In Virginia, bluegills should be 5 inches long in 3 years. Bluegills spawn several times between May and October when the water temperature is higher than 75° F. Since they produce many young, they serve as the primary food for bass in ponds.
The redear (or shellcracker) is shaped like a bluegill, but has a larger mouth, no dorsal fin spot, and a red or orange colored border on its gill flap. Redear usually feed on snails and insects on the bottom of the pond. Because they eat different foods than the bluegill, redear are a good addition to a pond. Redear grow faster than bluegill, usually reaching 6 inches in 3 years. Redear do not spawn as often as bluegill, so they rarely become overpopulated.
This species is recognized by its chin whiskers, forked tail, dark spots on its sides, and spines in its pectoral and dorsal fins. Channel catfish will eat almost any food item, but they prefer insects, small fish, and crayfish. Feeding them pelleted fish feed will increase their growth rate. In Virginia ponds, channel catfish should reach 14 inches in 3 years. Channel catfish can spawn in ponds, but they are often limited by lack of proper spawning structure. Milk cans, 5-gallon buckets, hollow logs, and wooden boxes make good spawning structures for catfish. To be effective, these structures must be laid on their side so the catfish can swim in and out of them. Because of egg predation by sunfish and fingerling predation by bass, few of the young survive. In channel catfish-only ponds, do not add spawning structure, because the catfish are likely to overpopulate and become stunted.
Three species of trout are commonly found in Virginia: brook, rainbow, and brown trout. Of these, only brook and rainbow trout are recommended for stocking into ponds. Brown trout are very predacious, hard to catch, and few commercial hatcheries produce them. Brook trout work well in ponds that are primarily spring-fed. They thrive when water temperatures remain below 70° F. Rainbows are generally the preferred trout to use in a pond because of their ability to handle warmer water temperatures than brook trout, their willingness to take lures or bait, their spectacular fighting ability, and their availability from local rearing facilities. Golden rainbow trout can be purchased for pond purposes. However, they are extremely attractive to birds of prey and poachers.
Generally, trout do not spawn in ponds and must be restocked periodically.
Stocking Options for New Ponds
The typical stocking plan for establishing a largemouth bass, sunfish, and channel catfish pond uses fingerling fish for economy (Table 1). The sunfish should be stocked in late summer or early fall (following pond construction and filling) so they can grow large enough to spawn the following spring, providing young bluegill for the bass to eat when they are stocked. You may begin harvesting sunfish 1 year after stocking, but largemouth bass harvest must be restricted for 2 years after stocking. If channel catfish catches decline 4 to 5 years after the first stocking, stock 50 (6 to 8 inches in length) catfish per acre every other year.
Another option is to stock adult fish, but this costs more than stocking fingerlings (Table 2). This option allows sunfish and largemouth bass harvest from the pond during the first fall. Fathead minnows can be added to provide food for the bass before the sunfish spawn. Under this option, channel catfish (6 to 8 inches in length) can be added to ponds stocked during the fall of every other year at 50 per acre.
Because largemouth bass are easily overharvested in ponds less than one acre in size, a good option for small ponds is to stock only channel catfish (Table 3).
Suggested trout stocking rates are 100 adult (greater than 8 inches) per acre or 200 sub-adult (less than 8 inches) trout per acre (Table 4). Smaller fish are cheaper, easier to transport, and can be fed with commercial trout food until they reach catchable size. If sub-adult trout are stocked into a pond with a healthy population of adult predators (largemouth bass, channel catfish, large trout), these predators may eat the young trout. A trout pond should be stocked every two to three years depending on harvest rates.
Fish to Avoid
Crappie, bullheads, yellow perch, pumpkinseed, and green sunfish should not be stocked because they tend to become overpopulated and stunted. Carp, including Israeli carp, and suckers are not recommended because they stir up the bottom, keeping the pond water muddy. Flathead and blue catfish are not recommended because they can consume the sunfish population in a small pond, resulting in unbalanced fish populations. Threadfin shad and gizzard shad are not recommended because they will become overpopulated.
Fish Suppliers and Stocking Techniques
Many commercial hatcheries produce fish for sale to pond owners. It is best to consult several suppliers to see who has the best prices and delivery schedules (see enclosed insert). In most cases, the chemistry of the water your fish are shipped in is different from the water in your pond. When your fish arrive, adjust them to your pond water before releasing them or they may die! This is done by gradually mixing pond water into the shipping container over the course of at least 30 minutes. Then, lower the container into the water and let the fish freely swim out when they are ready. Do not pour the fish out!