Grass carp also can be removed by shooting them as they feed near shore. Grass carp control vegetation for about 7 or 8 years after stocking. After this time they must be replaced. Grass carp, like many other species of fish are attracted to, and will follow a current of water. A spillway screen must be constructed to keep the fish in the pond while water is running across the spillway.
Screens are about two feet high and reach across the width of the spillway.
Screens can be made from one inch plastic or plastic coated wire mesh, supported by steel posts. Horizontal metal bars spaced one inch apart and welded into a frame also make good fish barriers, and are less likely to clog with leaves and other debris than mesh screens. Flesh is white, flaky and mild. Intermuscular bones are present but easily removed in large fish. Rottmann, R.W. and J.V. Shireman.