Pond Management: Managing Other Animals
Beavers are rodents that build lodges on land, along a pond bank, or in open water. The lodge is usually dome-shaped and is built of sticks and mud. Lodges usually have two or more underwater entrances. The den is above water and is used to raise families, for sleeping, and some food storage.
Most of the damage caused by beavers is a result of dam building, tree cutting, and bank burrowing. Their burrowing activity weakens dams, which may cause failure during major storm events. Beavers prefer trees such as poplar, sweetgum and pine. However, they eat the bark, twigs, and leaves of most woody plants growing near water. They also eat corn, soybeans, and other crops. Beavers often plug drainpipes in a pond, resulting in loss of water level control and damage to the emergency spillway.
Rip-rap above and below the water surface along the face of the dam will discourage beaver digging activity.
The use of traps is the most effective, practical and environmentally safe method of controlling beavers. Trapping should be done in the late fall or early spring. You do not need a license to trap on your property. However, if you give permission or hire someone else to trap, they must have a trapping license.
Muskrats construct their homes (burrows) by digging tunnels into the dam and along pond banks. These tunnels are dug both above and below the water surface to get to the burrows. The tunnels threaten the integrity of a dam. In a dam with muskrat burrows, rising and falling water levels could eventually cause the dam to leak and possibly fail.
Muskrats can be discouraged by eliminating sources of food such as cattails, bulrush, reeds, and arrowhead. Keeping the pond banks mowed also limits their activities. Placing rip-rap along the face of the dam, extending 2 feet above and 3 feet below the water surface will discourage digging. Wire screening (1 inch mesh) is also effective along the dam.
Trapping is the most practical method for controlling muskrat. Traps should be set in runways or den openings during the winter.
Crayfish are not harmful to fish populations. Some crayfish species build burrows that may cause leaks in a dam. Crayfish overwinter in their burrows in the bottom muds or pond banks. They become active when water temperatures are above 40° F. Crayfish are active at night, and traps should be set in late afternoon and left out all night. Crayfish traps can be made with ½-inch mesh chicken wire shaped like minnow traps. The funnel openings should be at least 2 inches in diameter to allow for easy entry. Traps can be baited with fish heads, meat scraps, dog food, or soybean cakes.
Crayfish are eaten by trout, bass, and catfish. A balanced fish population is one of the best ways to control crayfish numbers.
Turtles are common in ponds, but have minimal impacts on fish and waterfowl populations. They feed primarily on aquatic plants and invertebrates, and injured or dying fish (fish on a stringer are an easy meal!). Snapping turtles may take ducklings, but their overall impacts on populations are negligible.
From state waters, you may take up to 5 per day for personal consumption with a valid fishing license or hire a permitted commercial snapping turtle harvester. Both the recreational and commercial harvest seasons are from June 1st to September 30th. The only permitted form of trapping are hoops nets or homemade nets not exceeding 6 feet in length and 36 inches in diameter. Traps should be set in shallow weedy areas (not submerged), checked daily and can be baited with fish heads or other meat scraps.
Snakes do eat fish, but do not pose a threat to fish populations. Watersnakes are harmless and should not be killed. Clearing debris and mowing the pond edges reduces hiding places for snakes and will reduce their numbers.