Management is required to achieve maximum utility and enjoyment of a pond. What follows is a list of some of the things that can be done to manage a pond, and a general time of year that these activities should take place. Due to the variability of North Carolina’s climate, the months for each activity can vary. For example, grass cutting in the southeast may start earlier and last later in the season than the same activity in the western mountains.

Fish Harvesting

Recreational fishing is often a primary reason for having a pond, but harvesting/removing bass and bluegill is also very important for pond management. In new ponds, it is important not to harvest bass until the third year when they reach 12-14 inches in length. Harvesting bass too soon can upset the predator:prey equilibrium, leading to other problems.

Once harvest begins in the third year, unfertilized ponds receiving runoff from agricultural lands can support a harvest of about 10 to 15 pounds of largemouth bass per acre each year. In excavated or infertile ponds, which are common in the coastal plain, about 10 pounds per acre is a safe rate. If the pond is fertilized or fed, harvest rates can be doubled. Prioritize the removal of bass that are 13 inches or less, and release all bass that are 13-16 inches as they are aggressive feeders that help maintain stable bluegill populations.

Spread bass harvest throughout the fishing season and keep harvest records. These records will guide your future management efforts. Once your annual quota has been reached, fishing should be catch-and-release.

Typically, sunfish harvest should be 4-5 times higher than bass (i.e., harvest 4-5 pounds of sunfish for every pound of bass). It is very difficult to overharvest sunfish, but underharvesting sunfish can quickly lead to problems. When in doubt, keep it!

North Carolina Pond Management Guide

Levee/Dam Inspection

It is recommended that a pond owner assess the condition of their levee/dam at least twice a year. Winter is an especially good time to identify problems with the levee because the vegetation has died back, making holes and damage more visible. If the pond is drawn-down as part of a management plan, damage will be more visible.

A pond owner assessment checklist is available here; Clemson Pond Owner Dam Assessment Checklist

Trim Grass & Brush

The pond should have vegetation around it to stabilize the bank, control erosion, provide habitat and act as a nutrient buffer strip. But vegetation does need to be cut periodically to prevent brush and trees from growing. Tree roots weaken the levee and increase the likelihood of leaks, as well as encourage muskrats, beavers, and snakes to take up residence. Native plant species should be selected and there are many excellent choices. Avoid shrubs and trees. You can explore suitable native plants here; Native Plants for Coastal NC Wetlands

and here; North Carolina Wetlands Plant Guide

Apply Agricultural Limestone

Liming a pond involves adding crushed agricultural limestone (calcium carbonate) to the pond bottom. Liming provides major benefits for ponds in areas with acidic soils, a common problem in North Carolina. Limestone reduces the acidity of the bottom sediments, increases the alkalinity of the water (which can limit pH swings), and causes nutrients to be more readily available to phytoplankton. This is important if you plan to fertilize your pond to increase fish production. If the soils on pastures or fields near your pond require lime, the pond should be limed as well.

The best time to lime is in the fall and winter. When applying lime, the goal is to evenly distribute it across the pond bottom. To find out if your pond would benefit from agricultural limestone, contact your county Extension office to have the total alkalinity of your pond water tested. If it is below 20 mg/L, liming will likely be beneficial to fish populations. The lime requirement is determined by soil testing. In general, ponds will require at least one ton per acre. An application of agricultural limestone typically lasts for three to four years, depending upon the volume of water flowing through the pond.

All lime is not the same. Make sure to use only agricultural limestone in ponds with fish populations. Other forms of lime (hydrated, slaked or quick) can be used to lime empty ponds before fish are stocked, but if they are used in filled ponds, they will cause a spike in the pH, and likely kill many of your fish.

Use of Lime in Fish Ponds

Check Bloom Density

Phytoplankton are microscopic algae. They cause the greenish or green-brown color in ponds, and are referred to as a phytoplankton bloom. This forms the base of the pond’s food chain and is often the major source of (and consumer of) dissolved oxygen. Monitoring and maintaining an optimal bloom can maximize fish production while minimizing the chances of a low dissolved oxygen event.

Whether you fertilize or not, the phytoplankton bloom density should be monitored. An easy way to measure bloom density is to use a pie tin attached to the bottom of a yardstick or other material with measurement increments marked on it. Lower your pie tin into the water until it just disappears from view and then raise it until it can just be seen again. In farm ponds, a depth where the pie tin disappears should ideally be between 18 and 24 inches. If the phytoplankton bloom is thicker than this (depth reading less than 18 inches), don’t fertilize. If it is greater than 24 inches, a fertilizer application might be warranted.

Secchi Disk and Phytoplankton Bloom Management

Aquatic Vegetation Control

Aquatic vegetation control is a year-long process, starting with proper pond construction and involves continual monitoring. Essential to any control plan is correctly identifying the plants currently growing in a pond. A control plan might involve manual removal of plants, application of an aquatic dye to shade pond bottoms, winter drawdowns, and use of approved aquatic herbicides selected to control the problem plants. If herbicides are used, treating plants earlier in the season will be cheaper and more effective than waiting until later in the season.

Sterile triploid grass carp can be stocked and they can provide effective control for select submersed plants. A stocking permit is required from the North Carolina Wildlife Resources Commission and can be found here; Fish Stocking and Grass Carp Permit

Further information on grass carp can be found here;

Using Grass Carp in Aquaculture and Private Impoundments

More information on aquatic vegetation control can be found here; Aquatic Vegetation Control in Arkansas and here; NC State University Aquatic Plant Management Program

Winter Drawdown and Spring Refilling

An excellent management strategy for some ponds is a winter drawdown, where the pond is lowered to expose 35-50% of the pond bottom. This can prevent or correct bluegill overcrowding by concentrating the bluegill over the winter so that the bass can more readily eat them. Also, winter drawdowns can help control certain aquatic weeds by exposing them to freezing conditions. This is also a good time to add fish habitat or renovate older structures and the shoreline. Allow the pond to refill before the start of the spawning season the following spring. This technique is not recommended for ponds smaller than one acre.

Further information on a winter drawdown can be found here; Winter Drawdown for Aquatic Weed Control and Pond Management

Check Pond Balance

For the best fishing, fish populations should be kept in balance. There are two basic methods that can be used together to evaluate the body sizes and relative abundance of bass and bluegill in a pond.

One method to evaluate the bass and bluegill population is to use a seine to capture some of the young fish. The best time to do this is in mid-May to late June after the bass and bluegill have spawned. Using a 20-foot seine (4 to 5 feet deep with 3/8-inch mesh), make three to five semicircular passes in shallow areas of the pond and record what you catch. Allow the seine to arch so that the fish cannot easily swim around it. The fish caught in the seine hauls provide information on the reproductive success of the fish in the pond and also help determine if there are unwanted species present.

A well-balanced pond will have many recently hatched bluegill (less than 2 inches), some intermediate size (2-4 inches) bluegill and some recently hatched largemouth bass (1-4 inches). If there are no or few recently hatched bluegill, many intermediate size bluegill and no recently hatched largemouth bass, the pond is likely overpopulated with bluegill. In this case, the best course of action is to harvest as many bluegill as possible, use the winter drawdown described above, and stock 20-30 largemouth bass per acre (8-12 inches).

Conversely, if you catch in the seine many recently hatched bluegill, very few or no intermediate size bluegill and very few or no recently hatched largemouth bass, you may have a problem with bass overpopulation. In this case, remove about 35 pounds of largemouth bass (12 inches or less) per acre in a single year. This reduces competition for food among the remaining bass, resulting in increased growth the following years.

The second method to asses pond balance is to keep catch (and harvest) records throughout the year, and at times selectively fish for either bass or bluegill. It is useful to know how many fish, their sizes, and the condition of the fish. Catch records will provide a sense of the pond balance.

Further information is available in the North Carolina Pond Management Guide

More information about fish population management can be found here; Fish Management; Manipulating Pond Balance

Stock Fish

To maintain the desired pond balance, it may be necessary to stock additional fish. If the pond is small and catfish are desired, they will need to be restocked periodically because they will usually not reliably reproduce in small ponds. Minnows might need to be stocked to enhance bass populations by providing additional forage. If the pond is bluegill heavy, bass might need to be stocked to increase bluegill predation. Regardless of the species, the time to supplementally stock fish is during spring or fall, when water temperatures are cooler. Almost without exception, fish should not be stocked during the summer months. Fish should be purchased from a reputable dealer.

Largemouth Bass should be stocked in the spring of the year following the stocking of the prey species. This gives the prey species sufficient time to become established and spawn.

A stocking permit is required from the North Carolina Wildlife Resources Commission and can be found here; Fish Stocking and Grass Carp Permit

A list of fish suppliers can be found here; Fish Suppliers

Feed Fish (if Desired)

It may be desirable to offer supplemental feed to the fish. Many species of fish, including catfish and bluegill, will eat prepared feeds. Predators like largemouth bass and crappie will usually not eat formulated feed, but bluegill will turn the supplemental feed into increased food for the predators. Thus, a feeding program increases the production of many kinds of fish allowing for higher stocking densities and faster growth. Feed is particularly beneficial in lakes and ponds where the production of natural food is limited by low nutrient levels or low productivity. If you feed, you do not need to fertilize.

Use a floating feed that allows observation and only feed what the fish will consume in 5-10 minutes. Select a quality feed that is formulated specifically for fish. The least expensive and most appropriate feeds for most ponds are those labeled for catfish and that contain at least 28% protein. Higher protein levels are more expensive and unlikely to produce more fish. Do not use feeds designed for other animals. The nutrient requirements of other animals are different from fish and may negatively impact their health.

If you decide to feed fish, while they will eat when water temperatures are above 50F (trout will eat at lower temperatures), feeding during the summer will give better growth.

Pond Fertilization (if desired)

The addition of fertilizer to a pond can stimulate additional phytoplankton growth, enhancing the food chain, leading to increased fish production. Many ponds to do not need fertilization due to being naturally fertile, and additional nutrients from fertilization can lead to increased nuisance aquatic vegetation and other problems. If the pond water is low in alkalinity, additional fertilizer will not be accessible to the phytoplankton. If the pond already has a nuisance aquatic vegetation problem, fertilizer will make this problem worse. Do not fertilize if the pond is muddy (turbid) or has high outflows. Fertilizer can be added in the spring once water temperatures reach 65F, with the goal of stimulating a phytoplankton bloom (a Secchi disk reading between 18-24 inches). Achieving and maintaining the desired bloom density may require fertilizer several applications throughout the season. If you decide to start a fertilization program to increase fish production, you should continue every year. Stopping a fertilization program can shift the pond fish balance. This should be considered prior to starting a fertilization program.

Further information can be found here; Pond and Lake Water Quality- Fertilization

And here; Fertilization of Freshwater Fish Ponds