A frequently used method for controlling vegetation in Missouri ponds and lakes is stocking grass carp. The grass carp (Ctenopharyngodon idella) is a long, slender, silvery- white fish. This Asian minnow has been known to reach a length of 4 feet and weigh nearly 100 pounds. Grass carp primarily feed on submerged plants more than other types of aquatic vegetation. As a result, they can be an effective tool for managing excessive aquatic vegetation (weeds) in a pond.
Although grass carp can provide an excellent method of aquatic weed control, they are commonly over stocked in lakes and ponds leaving little or no vegetation in the entire body of water. Aquatic plants are the basis of the food chain in lakes and ponds and are important in maintaining a healthy fishery. Plants keep the water oxygenated, provide food, cover and nesting sites, and stabilize the shoreline and bottom. In short, if good fishing is your goal, the plants in your pond should be managed, not eliminated. Ideally, a pond or lake should have 15-20% coverage of rooted aquatic vegetation. If aquatic vegetation falls below this recommended level, you may need to reduce the number of grass carp in the lake.
Grass carp can be very difficult to catch on a pole and line. They are very cautious and reclusive fish, preferring to feed unobserved and undisturbed. They are commonly seen feeding in shallow coves and are easily spooked by movement on shore. Grass carp are spectacular fighters and can be very difficult to land. The most effective method of catching grass carp on rod and reel is to bait an area and fish.
Using corn for bait is effective, clean and inexpensive. You can bait a site by throwing the contents of five to 10 cans of corn into the water about 10 to 20 feet from shore. Make sure the area you bait is free of brush or other obstacles to avoid getting snagged when fighting a fish.
Feed corn is cheaper than canned corn, but you need to soak it in water for several days before using it to allow it to ferment. To prepare the feed corn for baiting, fill a bucket about ½ full with feed corn. Cover the corn with water and set the bucket in direct sunlight for 3-4 days. After the corn has fermented or soured (it will smell), scatter the corn in the water in the same place you are going to fish several days prior to fishing the area.
Many types of bait have proven successful; however, spoiled corn, bread dough balls and live earthworms have proven most successful. You can make a dough bait using bread and spoiled corn. Mix bread and spoiled corn together in a small container. The mixture should be thick enough to stick together and mold onto the hook. Bait your hook with just enough bait to cover the hook.
Approach the baited area quietly and cast your line into the baited area. Grass carp are very wary and are easily spooked. Light line (6-8 pound test) and light to medium fishing equipment is preferred. Use only enough weight to cast. A BB split shot or slip sinker is often the best. Grass carp will drop the bait immediately if it feels the slightest resistance.
After casting the bait, leave a little slack in you line. When you see the line begin to tighten, set the hook and hold on. Grass carp are known to make several long runs when hooked so a fairly loose drag will help keep fish on the line.
Some other baits that are effective for catching grass carp include cherry tomatoes, watermelon (the red and the rind), fresh cut grass, acorns, dog food, catfish food, catalpa worms, tomato worms, grasshoppers, new oak leaves and green, kidney or lima beans.
Removal of grass carp using archery methods has proven successful. However, grass carp become even more wary when hunted. Baiting grass carp into an area (as described above) can improve success.
They may have a poor reputation, but carp are good to eat when properly cleaned and cooked. Clean grass carp by filleting and skinning the slabs of meat along their sides. Make sure you remove the dark red strip of meat along the lateral line. After cleaning, you can bake, broil, fry, pickle, can or barbecue the flesh. Grass carp are especially good when smoked. Carp are considered bony fish, but you can reduce or eliminate any fish bone problems by scoring the fillets almost all the way through, then frying them in hot oil. You can add carp meat to chowders or grind it up to make a fish loaf or patties. Your local Conservation Department office has more information on carp fishing and recipes for preparing carp.
Grass carp are a very effective tool to manage the aquatic vegetation in your lake. When used properly, they can help a pond owner control aquatic vegetation and sometimes provide an alternative fishing opportunity.
The Missouri Department of Conservation has other Aquaguides and fisheries biologists available to assist you with your pond and lake management needs. Contact your local MDC Regional office or go on-line at mdc.mo.gov for assistance.