HOW TO PRODUCE BAIT MINNOWS IN PONDS

An increase in the amount of fishing in recent years has increased the demand for bait minnows. With proper planning and care they can be produced without great effort, and a small pond can furnish adequate bait for a private owner or a fishing club. This bulletin is not intended for large-scale commercial production.

An old pond can be made to produce bait minnows, but any fish it contains must be removed before minnows are stocked. Other fish will decrease production of minnows either by preying upon them or by competing with them for food. The unwanted fish can be removed by draining the pond or with chemicals.

Selecting a pond (or a pond site if a new pond is to be constructed) is the first important step in planning for bait minnow production. Except for the size and depth the same criteria used in selecting a fishing pond should be followed. The size may range form one-tenth of an acre upward, and a minimum depth of eight feet is necessary to prevent winter kill and to withstand drought. Ten acres of watershed area for each surface acre of water is sufficient to maintain the water level in the pond. The watershed should be gently sloping and should be kept in permanent cover.

CONSTRUCTION:

For a new minnow pond, construction methods recommended for the regular farm pond should be followed. The dam and the pond basin should be properly surveyed and staked out: before the fE for the dam is started, the topsoil containing roots and decaying vegetation should be removed from the dam site. A core cutoff ditch deep enough to reach clay subsoil or at least well below the topsoil should be excavated through the entire length and through the center one-third of the width of the dam at its base. This is one of the most important phases of construction. By excavating this cutoff ditch down to the subsoil, the clay core of the dam can be started on compact earth. This makes a seal which reduces the possibility of leakage through the base of the dam. The spillway should be wide enough to carry the maximum surface runoff in a stream not more than three inches deep, and the dam must be extended to at least two feet above the maximum flow level in the spillway. Deepening the edges of the pond will help in controlling undesirable aquatic vegetation. New ponds - and if possible, old ponds also - should be equipped with a drain pipe and the basin should be graded so that it can be drained completely.

TREATMENT OF THE WATERSHED:

Following construction, all raw areas in and around the pond including the dam, spi11ways, and watershed should be limed, fertilized, mulched and seeded. Agricultural limestone should be spread at the rate of three tons per acre. In addition, either manure or commercial fertilizer should be spread evenly over all raw soil areas except those that will be covered with water when the pond is full. Fifty pounds of superphosphate should be added for each ton of manure. If commercial fertilizer is used, 8-8-8 or its equivalent should be spread at the rate of four to six hundred pounds per acre. The lime and manure or fertilizer should be worked into the surface by disking lightly and harrowing.

All raw areas, including the basin itself, should be mulched. Straw, hay, or any type of mowed vegetation should be spread evenly about five inches deep, and packed as tightly as possible. Neither manure or commercial fertilizer, should be used in the area to be covered with water. The high nitrogen content of the fertilizers stimulates the growth of undesirable algae or pond scum.

The raw soil areas should be seeded with a nurse crop of small grain and with grasses for permanent sod. The following nurse crops are recommended according to the time of year seeding is done: late summer of fall - rye or wheat at the rate of lOO pounds per acre; spring or early summer - oats, at 75 pounds per acre; hot. dry! midsummer - Sudan grass, at 25 pounds per acre.

For permanent seeding, use the sod-forming grass recommended by the County Extension Director for the locality. Include the dam and the spillway in the permanent seeding. The life and quality of the minnow pond depend greatly upon establishing a good sod on the areas denuded during construction. If livestock have access to the area, the pond must be fenced to prevent damage to the banks and dam.

BAIT SPECIES:

Either of two species of minnows is recommended for stocking the pond: the fathead minnow (Pimephales promelas) and the golden shiner (Notemigonus crysoleucas) have been found to be particularly reliable producers. Both attain a size suitable for bass fishing, and small fatheads are desirable bait for smaller sunfishes and other game fish.

Fathead Minnows:

Fathead minnows should be stocked at the rate of 300 adults per surface acre of water. The first stocking can be made anytime during spring, summer, or autumn. Adult minnows stocked in April, however, will produce bait-size young by the end of the growing season. The quantity and size of the minnows produced will vary considerably in different ponds even though similar management practices are followed. In Missouri, as many as 50,000 bait-size minnows per acre of water have been produced in experimental ponds.

Golden Shiners:

Golden shiners should be stocked at the rate of lOO per surface acre of water. Adult minnows stocked at this rate in April or May will produce usable bait within the first growing season. As with the fathead minnows, the size and quantity of golden shiners produced will vary considerably from one pond to another. However, an acre pond may be expected to produce 6,000 minnows from three to four inches long, or a greater quantity of a smaller size, in one growing season. As many as 20,000 minnows per acre of water have been produced in experimental ponds in Missouri. Although golden shiners are rehtively easy to raise, the production of bait-size minnows per acre of water is considerably less than it is for fathead minnows. Also, they are difficult to keep alive in transporting and handling.

In selecting broodstock, take care to obtain golden shiners of both sexes. The females are usually larger than the males; if only the hrgest specimens are selected, it is possible to get many more females than males. During the breeding season, males can be distinguished from females by their deeper golden color and rough sides in addition to the smaller size.

The mulch placed in the pond basin will sene as a spawning place. The eggs are deposited on filamentous algae as well as on the mulch; an old pond will have enough algae and other vegetation in it to supply spawning facilities.

FERTILIZING:

The use of commercial fertilizer is recommended for stimulating growth and increasing the production of bait minnows only when they are grown commercially. An unfertilized minnow pond will usually produce enough minnows for private use.

Fertilizer is applied to stimulate production of tiny plants which supply food for small animals eaten by the minnows. For the maximum production of bait minnows in ponds already stocked, fertilizing should be started as soon as the temperature of the water reaches 50°F. Depending upon geographic location, pond water will reach that temperature in Missouri at some time during March. In new ponds, the first application of fertilizer should be made about a week before stocking: 16-20-0 commercial fertilizer, at the rate of 50 pounds per acre at 15-day intervals as needed is recommended.

Not more than that amount per acre should be used at any one time, and not more than 1,000 pounds per acre should be applied annually.

The dense growth of small organisms stimulated by the fertilizer will cause the water to maintain a greenish or brown color. These small organisms should be sufficiently dense to obscure a man's hand in 12 inches of water. In some waters it is possible to maintain the production of food organisms at this rate by applying the fertilizer less frequently. This ruleof-thumb test should always be made before each application of fertilizer.

HARVESTING:

To realize the greatest return, whether minnows are reared for private use or commercially, the crop must be handled and harvested properly. The greatest loss usually occurs in handling and holding the harvested crop. These losses occur mainly from improper methods of seining and as a result of improper aeration, temperature control, or overcrowding in holding tanks.

For private use a small minnow seine can be used to get the weekend supply of bait form the rearing pond. However, if any quantity is to be harvested, a longer, deeper seine should be used so as to obtain the desired number in as few hauls as possible. For this purpose, a onefourth-inch mesh seine 15 feet long and six feet deep, tied on four-foot brails, is recommended. In larger ponds from which the entire crop is to be harvested, a quarter-inch mesh seine should 200 feet long and six to twelve feet deep can be used. However, if the pond is equipped with a drain pipe, the water level- should be lowered before seining and a shorter seine should be used. Unnecessary roiling of bottom mud should be avoided. Muddy water can suffocate minnows in the seine. If a large quantity of minnows is caught, a bag should be formed about them by holding a lead line, float line and the ends of the seine above the water. Then trapped minnows should be moved to clean water before they are removed from the seine. This is merely an added precaution to prevent injury or suffocation. The minnows should be dipped from the seine with a small hand net.

The water in holding or carrying tanks should be well aerated, and the temperature should be as nearly as possible the same as the temperature of the pond water. Unless the change is gradual, minnows cannot tolerate more than a 10-degree change in temperature when they are transferred from the pond to a holding tank or from one tank to another. Tanks may be aerated with running water or air. If running water is used, there should be a continuous flow of one gallon per minute for each 25 gallons of water in the tank, and at least two pressure jets should be used in each tank. In large tanks one pressure jet should be used for every 25 gallons of water. If compressed air is used for aeration, it should be passed into the water through carborundum air stones attached to the end of each air hose, or through a perforated tube. In a well aerated 25-gallon tank of water it should be possible to keep 600 minnows alive three to four days. In hot weather, however, they may not remain in good shape for more than two to three days even though the tank is well aerated.

City water is usually not satisfactory for minnow-holding tanks unless it is well aerated and filtered through charcoal to remove chlorine. Occasionally city water contains more chlorine than minnows can tolerate; and unless this precaution is followed, an entire stock of minnows can be lost within an hour's time.

The use of a filter pump is an effective and inexpensive method of aerating water in truck or stationary tanks. It is a "T" shaped metal tube which mixes air with water in a tank when it is insta11ed in a pipe through which water circulates continuously. This system is ordinarily used on fish distribution trucks, and it can be insta11ed on a city water line to aerate water in stationary tanks.

To prevent holding tanks from becoming contaminated with fungi and harmful bacteria, either of which may cause disease in minnows, the tanks should be kept clean and should not be over-crowded. Not more than a three or four day supply of minnows should be kept in holding tank at one time.

After minnows have been removed from a tank, it should be drained and scrubbed with a solution of sodium hypochlorite and water, made up by dissolving one ounce of sodium hypochlorite in eight gallons of water.