ILLINOIS — Fall can be a great time to stock a new private farm ponds or established ponds. The Illinois Department of Natural Resources shares tips on how to have a successful stock to last you far into the future.

Private Ponds

Constructing, Stocking and Maintaining Private Ponds

Pond management is more difficult than most people realize. Many enthusiastic beginners believe they can put up a dam, wait for it to fill, throw in some fish, wait a couple of years and then fish happily ever after. As the “veteran” pond owner knows, this is not the case. Proper pond management takes diligence, work, expertise and money.

Pond Construction Tips

1. Make sure the pond site lends itself to the proper maintenance of a pond. Do not dam up a gully that has a square mile of run-off running through it. We recommend that the watershed acreage be between 10–20 acres for every surface acre of pond. Example: A three-acre pond would have a watershed of 30–60 acres.
2. Contact the local Natural Resource Conservation Service in your county. They are an invaluable source of information regarding pond construction.
3. Plant grass waterways and edge around the pond. SOIL EROSION WILL CAUSE A POND TO GO BAD QUICKER THAN ANY ONE FACTOR.
4. Put a core trench (key) in the dam.
5. If the pond is larger than 1.5 acres, it would be to your benefit to put a drain in it. Four inches (4″) is large enough. This will allow you to draw water out of the pond and will come in handy in future management projects, i.e., rehabilitation.
6. Keep trees from growing on the dam.
7. A sediment retention basin or silt trap in the upper end of the pond would be beneficial in keeping soil from filling in your pond.

Fish Stocking Tips

Ponds in Illinois vary greatly in their fish stocking needs. The owners, managers and users of these ponds also may differ in their sport fishing objectives and require a wide selection of stocking options. Therefore, it is important to discuss pond stocking with a District Fisheries Biologist.

Before the fish stocking decision is made, careful analyses of pond characteristics and angler preferences must be made. Some of the factors affecting the decision include pond type, size, depth, water chemistry, fertility, existing fish population, expected fishing pressure and harvest, and most importantly, what fish do the anglers want?

The most widely used and successful stocking combination for ponds in Illinois is largemouth bass, channel catfish, bluegill and redear sunfish. These species are popular among fishermen, and are biologically adapted to a wide variety of pond conditions. These species effectively utilize natural and artificial foods, and are compatible with many other species that might be stocked later. The concept of this stocking combination is that the bluegill eat small aquatic insects and in turn serve as food for bass. The bass control the numbers of small fish so that those remaining grow to large size.

One of the most important points in producing a viable sportfish population is to stock the pond correctly initially.
Follow these tips:

1. Do not go to another lake or river, catch some fish and stock them into your pond.
2. If possible, do not allow anyone to put fish into your pond at anytime.
3. In central Illinois, pond should be stocked with 500-700 bluegill per surface acre, 0-300 redear sunfish per acre, 100 largemouth bass and 100 channel catfish per acre. These fish should be fingerlings. Do not stock adult fish (see 2 and 3).
4. Every other year, thereafter, stock 15-30 8-10″ channel catfish per acre.
5. There is no need to stock any other fish, assuming you are properly managing your pond.
6. Do not stock carp, bullheads, crappie, hybrid sunfish, green sunfish, trout, walleye, extra bass, fathead minnows, etc. in your pond. You are trying to establish a balanced predator-prey population between bass and bluegill. Any other species introduced could negatively affect this balance.
7. Always be aware of aquatic invasive species and be very careful not to stock any of these plants or animals into your pond. Before purchasing fish or plants for your aquarium, backyard pond, or water garden, make sure it is legal to purchase or possess your desired species.Under Illinois state law, it is illegal to purchase or possess “injurious species” (common names found here) without a permit from the Illinois Department of Natural Resources.

Sources of Fish Stocking

There are several local, statewide and regional sources of fish for stocking ponds. Most local county soil and water districts sell a variety of fish species. Also, there are numerous private fish dealers and hatcheries throughout the Midwest that supply and deliver live fish. Here is a listing: Fish Dealers

Feeding Fish

Feeding is not recommended as a normal procedure in pond management. Caution must be exercised not to use too much food. Too much unused food in a pond may cause a fish kill due to the decomposition process. However, if you insist on feeding your fish, several animal food manufacturers offer fish food pellets for sale. These foods are used most successfully in trout and catfish culture. However, pelleted fish food can also be used by the pond owner to feed bluegill. Bluegill do not usually concentrate in one place to feed; therefore, the pelleted food would have to be scattered in the shallow water areas or placed on floating feeders around the entire pond. Pelleted fish food can be fed at the rate of 2 pounds per acre per feeding. Once the fish begin taking the food, the amount can be increased, not exceeding 10 pounds per acre per day. The best guide in feeding fish is to use no more than they consume in 15–20 minutes. Feeding bluegill may result in larger and fatter fish, but not necessarily better fishing. Bass do not take pelleted food very readily unless they learn to do so when very young (2 inches).

Fish Population Management Tips

1. Put a 15″ length limit on largemouth bass, especially for the first three years. Any caught smaller than that should be released.
2. This limit may be lifted after the initial phase, depending on the bass/sunfish population structure.
3. Bluegill/redear (sunfish) should be harvested at the rate of 50–70 lbs/acre/year after the second year, depending on the productivity of the lake.
4. Bass should be harvested at the rate of 20–30 lbs/acre/year after the third year. That same figure could be used for channel catfish as well.
5. If bluegill are stunted in your pond, they need to be drastically “thinned” out. Harvesting by hook and line generally will not reduce their numbers significantly. You will need to consult the fisheries biologist who can recommend possible solutions.

Removing Undesirable Fish

Undesirable fish,such as carp and bullheads, can be removed by two methods: draining and chemical treatment. If the pond can be completely drained, the pond bottom should be left dry for several weeks. If any water is left after draining, it should be treated with a fish toxicant to assure a complete fish kill. In order to use aquatic pesticides, such a rotenone, a Permit to Remove Undesirable Fish must be obtained from the Department of Natural Resources’ Division of Fisheries. Aquatic pesticides are listed by the USEPA as “Restricted Use Pesticides”, they can only be received and possessed by a Division of Fisheries biologist. Treatment of water areas with fish toxicants must be done by one of these biologists per Illinois Administrative Rule 890. The permit to Remove Undesirable Fish and a detailed explanation of Rule 890 can be obtained from the IDNR fisheries biologist.

Emulsifiable rotenone is very effective for the reduction or eradication of undesirable fish populations. The chemical inhibits a biochemical process at the cellular level making it impossible for the fish to use oxygen in the release of energy needed for body processes. The fish cannot be revived by transferring them to untreated water. Rotenone affects all species of fish, although susceptibility to the chemical varies between species. Emulsifiable rotenone, 5 percent or 2.5 percent synergized, is generally used at a minimum concentration of 3 parts per million (1.0 gallon per acre foot). A stronger concentration may be required in waters that are very alkaline and highly turbid, caused by either algae or silt. Swimming can take place in waters treated with rotenone following completion of the application of the rotenone.

Fish Kill

Many things can cause the death of fish in ponds, and once the fish are dying, it is usually too late to stop the kill. However, many fish kills can be anticipated, and measures can be taken to prevent them.

Winter Kill

During winter, the oxygen supply under the ice depends upon the passage of light and the production of oxygen by tiny plants in the water. If snow covers the ice, sunlight cannot penetrate and the plants are unable to produce oxygen. The supply of oxygen is gradually used up by decay processes and by the respiration of fishes and other aquatic animals. If the snow remains on the ice long enough, oxygen is depleted and the fish suffocate. Dead fish are usually found in the spring after the ice melts. However, if the kill occurs early in the winter, there may be few, if any, dead fish observed when the pond opens in the spring.

Winter kill is most likely to occur in fertile, shallow, weed-filled ponds. To prevent winter kills, deepening the pond, and removing fertile organic matter will help. Removing the snow cover from the ice will permit light to penetrate to the underlying plants. Making holes in the ice will not help. Artificial aeration can help fish survive and prevent oxygen depletion. Compressed air systems should be utilized in depths which exceed eight feet.

Summer Kill (Aquatic Plant Die-Off)

Ponds that contain an abundance of submersed aquatic plants or algae sometimes have a fish kill when these plants die suddenly from natural causes or from herbicides. Aquatic plants frequently die during midsummer and use up the oxygen in the water as they decay and fish suffocate as a result. This type of summer kill almost always occurs about sunrise when the dissolved oxygen is at its low point for the day. Natural die-offs of phytoplankton (algae) blooms are a common cause of summer kill. On rare occasions fish may die or be in distress in mid-afternoon because of increased pH of water, supersaturation of oxygen (gas bubble disease), or toxic algae blooms.

To prevent a summer kill, control of the rooted aquatic vegetation and algae so that they never become dense is recommended. If the stand is dense, treat only a part of it at any one time and allow that part of the vegetation to decay before further treatment. Artificial aeration can help fish survive and prevent oxygen depletion. Compressed air systems should be used in depths that exceed eight feet. In lakes and ponds where depths do not exceed eight feet, blower systems are more efficient.

Summer Kill (Temperature)

Water temperatures in shallow ponds can reach 90 to 95 degrees during hot summer months. Water holds very little oxygen when its temperature is above 90 degrees F. On days with little breeze, little or no oxygen is added to the water, and the dissolved oxygen may disappear entirely just before dawn, and as a result, fish would die from suffocation.

To prevent this kind of summer kill, ponds should be deepened so that 25 percent of the area is 7 to 10 feet deep or deeper. Artificial aeration can also help fish survive and prevent oxygen depletion. Compressed air systems should be used in depths that exceed eight feet. In lakes and ponds where depths do not exceed eight feet, blower systems are more efficient.

Organic Pollution

Barnyard, feedlot, silo, and sewage drainage that consumes oxygen as it decays can quickly deplete the oxygen in a pond and cause fish to die from suffocation. Many times these kills are noticed after a rain when organic pollution has washed into the pond.

To prevent fish kills from organic pollution, organic wastes need to be kept from entering ponds by the use of proper livestock confinement practices and appropriate agricultural practices.

Pesticides

Farm crops on the watersheds of ponds are often sprayed with pesticides. Rain may wash this material into the pond and readily cause a fish kill from exposure to the chemicals.

To prevent such a kill, caution should be exercised in the selection and application of pesticides and in the timing of treatment. Also, application equipment should not be spray washed in or near ponds.

Natural Mortality

In the spring, a few large fish may be found dead along the shoreline. Such mortalities are often the result of natural causes. The natural resistance of fish to disease is lower in the early spring than at any other time of the year. Larger fish often seem to be more susceptible to disease than smaller fish.

Industrial and Mining Wastes

Many industrial wastes are toxic to fish. Other industrial wastes are organic, consuming dissolved oxygen and killing fish by oxygen depletion. Mining wastes kill fish by the direct effects of acids and sulphur compounds.

To prevent such kills, wastes from mines and industrial plants should be kept from entering ponds.