Pond Stocking and Management

Stocking and Managing Iowa Ponds

Years of experimentation have shown three fish species are best suited for Iowa ponds. Largemouth Bass and Bluegill are the primary species stocked in ponds, and must be stocked in combination to provide a good fishery. Bluegills are an excellent panfish and serve as prey for largemouth bass. Channel Catfish are also recommended for pond stocking due to their popularity with Iowa anglers and opportunity they provide for excellent fishing. All three species are available from many private hatcheries in Iowa.

Bluegills
Bluegills provide most of the "take home" catch and most of the forage for largemouth bass. A bluegill rarely exceeds one pound in weight, but pound for pound it is the sportiest fish around. The average size caught is 6 to 7 inches and 1/4 to 1/3 pounds. Bluegills live about five years, but 13-year-olds have been recorded. Bluegills reach sexual maturity at age one with a 4-inch female producing about 4,000 eggs.

Spawning takes place from May through late August. Male bluegills build nests (shallow depressions) in shallow water and lure a female to the nest to lay eggs. The male guards the eggs and nest during incubation which takes 2 to 5 days. He continues to guard the newly hatched fry until the yolk sac is absorbed and the fry swim off. These young bluegill provide most of the food needed to have a healthy population of bass.

Hybrid sunfish should not be used as a substitute for a forage species such as bluegill, especially in new ponds. Bluegill reproduction provides the necessary forage (small bluegill) for predator species such as bass. Reproduction by hybrid sunfish is very limited and not enough to maintain reasonable growth and condition for larger predators.

Largemouth Bass
Largemouth bass, the trophy fish in ponds, is the major predator of young bluegill. A past state record largemouth bass, caught from an Iowa pond, measured more than 24 inches long and weighed over 10 pounds. Under ideal conditions largemouth bass spawn in their second year of life, but most spawn in their third year. Male largemouth bass also build nests similar to bluegill, but the nests are larger. Spawning occurs in May and early June in shallow water. A female largemouth bass 10 inches long will produce about 2,000 eggs, but an older, bigger largemouth bass can produce 15,000 eggs. Bass eggs usually take 3 to 10 days to hatch. Male bass care for the fry until they are about 10 days old.

Channel Catfish
Channel catfish, considered as bonus fish in Iowa ponds, provide quality angling. Channel catfish grow large in ponds with some over 15 pounds. Channel catfish become sexually mature at two years old, but most reproduction comes from older fish. A female produces about 4,000 eggs per pound of body weight. Spawning occurs in June when the male builds a nest similar to largemouth bass and bluegill, except it is usually more protected. Male channel catfish also guard the nest and care for the young.

Correct Stocking is a MUST for Good Fishing
Some of Iowa's best fishing for Largemouth Bass, Bluegill, and Channel Catfish is provided by properly stocked ponds. Private hatcheries in Iowa have provided great success with the following rate in new or renovated ponds:

  • 100/acre 3- to 6-inch Largemouth Bass
  • 300/acre 3- to 5-inch Bluegill
  • 100/acre 4- to 6- inch Channel Catfish

Hybrid sunfish should not be used as a substitute for a forage species such as Bluegill, especially in new ponds. Bluegill reproduction provides the necessary forage (small bluegill) for predator species such as bass. Reproduction by hybrid sunfish is very limited and insufficient to maintain reasonable growth and condition for larger predators.

Key to Pond Management: Harvest Bluegills, Release Most Largemouth Bass
Iowa ponds contain about 250 pounds of bluegill per surface acre of water; therefore, this species will provide most of the fishing in a pond. Bluegill harvest can begin the second year after stocking. No limits are necessary for bluegill in private ponds because they are plentiful.

Largemouth bass populations in a balanced Iowa pond will reach 50-75 lbs/acre. Largemouth bass should not be removed until the third year after stocking. No more than 15 largemouth bass/acre over 14 inches in length should be removed each year. Greater harvest rates will reduce the quality of largemouth bass and bluegill fishing. Removing too many largemouth bass may result in small bluegills due to their prolific reproduction.

Channel catfish harvest can typically begin within three years after initial stocking. Harvest should not exceed 15 fish/acre and can be restocked once half the original population has been harvested. Large fingerlings (at least 8-inch) should be stocked when introducing channel catfish in established ponds to escape predation by largemouth bass.

Fish Species Other than the Largemouth Bass, Bluegill and Channel Catfish Combination
Although the largemouth bass, bluegill and channel catfish combination typically does well on its own, Fathead Minnows are sometimes stocked to provide initial prey for largemouth bass but they will not sustainable.

Walleye and Northern Pike can be stocked into ponds without harm, but they rarely reproduce in ponds and must be stocked periodically to maintain their populations. Walleye seldom grow large in ponds, but northern pike often do.

Black Crappie may be suitable in ponds larger than 5 acres, but should not be stocked until largemouth bass and bluegill populations are well established.

White Crappie and Yellow Bass are not well suited for ponds because they usually produce little fishing, seldom grow to acceptable size in ponds due to excessive reproduction and compete directly with fish. Hybrid Striped Bass should also be avoided due to their direct competition with other species.

Vegetation Management and Grass Carp
The Iowa DNR does not stock Grass Carp into public waters and does not recommend them for stocking private ponds. Stocking grass carp often results in increased algal growth and near elimination of all aquatic vegetation. Once stocked, grass carp are hard to remove and can live beyond 20 years.

Although the DNR does not encourage stocking grass carp, they can legally be stocked into private ponds in Iowa. If grass carp are stocked into a private pond, the DNR recommends a conservative stocking of no more than 1-2 ten-inch fish per acre. Pond owners who opt to go this route should be patient as vegetation control may not be seen for 2-3 growing seasons.

Restocking should not occur until rooted aquatics become a problem. Often, additional fish are stocked because vegetation control is not apparent immediately. When the happens, the pond ends up with too many grass carp resulting in too little vegetation, poor water quality, and ultimately sport fishing suffers.