Access digital copies of guides and regulations publications from the Nebraska Game and Parks Commission.
Issue link: http://digital.outdoornebraska.gov/i/605475
64 • Nebraska Game and Parks Commission likelihood of future problems. Removing plants mechanically or physically provides only temporary relief and may be practical for only a small portion of the pond. The processes will likely need to be repeated several times throughout the growing season and in subsequent years. Chemical Treatments If you are unable to determine a source of nutrients, or if you still have vegetation problems following nutrient reduction and removal efforts, chemical treatments can then be considered. Many herbicides that control aquatic vegetation in ponds are available from commercial distributors. Most are listed as restricted use and must be applied by a licensed aquatic pesticide applicator. Some advantages of herbicides are: • They generally produce fast results. • They are usually easy to apply. • They are often available locally. • They are normally selective for a particular type of vegetation. • They give the pond owner control over how much vegetation is eliminated. Some disadvantages of herbicides are: • They are expensive. • They usually require multiple applications to maintain control. • They can be dangerous to the applicator and aquatic animal life if applied incorrectly. • The plants must be correctly identified, sometimes to species. • The treatment area must be accurately measured. Typically, all that is needed is to open up some fishing and boating lanes or a few shoreline areas for bank fishing, swimming, and wading. If a large portion of the pond surface will eventually be treated, or the growth is extensive, treat only 1/4 to 1/3 of the problem area at a time, and wait about two weeks between subsequent applications. If too much vegetation is killed, its decomposition will deplete available oxygen which can stress or even kill fish. Most problem vegetation species should be treated early in the season when they first start growing, not during summer months when the dissolved oxygen levels in the pond may already be low or widely fluctuating. Some plants, such as cattails and water lilies, should be more mature when certain chemicals are used; otherwise, only the top will be killed and the rest of the plant and its roots will be unaffected and regrow. Keep in mind most aquatic plant species die-off naturally at the end of their growing season and regrowth of new plants from plant fragments, root stock, and seeds is likely. Read and follow the directions and precautions on the herbicide label. The label will list what plants can be controlled, dosage recommendations, and when application should occur. Also listed on the label will be any restrictions on usage of treated water, including human contact (swimming, wading, or drinking the treated water), fish consumption, irrigation and livestock watering. Check the pond water temperature. Some chemicals will not work in cold water. Some herbicides (contacts — such as copper algacides, endothall and diquat) work very quickly by killing the plant tissue they contact and can be used for "spot" treatment. Other herbicides (systemics — such as 2,4-D, triclopyr and glyphosate) can be used for spot treatments but work slowly and move from Rarely does the entire pond need to be treated. Chemical treatment should be kept to a minimum. Try to avoid applying chemicals during fish spawning periods.