It is the purpose of this volume to survey and assess the management problems of recreation waters and to present case problems from the field in which the technical data, published literature, and the operations mechanics are given in sufficient detail to provide a format for practical analysis and application. Special emphasis has been given to measures of control of Eurasian watermilfoil.The primary and secondary uses of a body of water determine the need, frequency, and kind of aquatic plant control required to meet the needs of a specific situation. That is to say, a given body of water may be used primarily, or even exclusively for such activities as fishing, boating, or swimming, and the water itself may be used for domestic (potable water), industrial production, and/or agriculture. These uses may seem to be incompatible in themselves, but it is incumbent upon management to supply the optimum conditions for total water use.

This volume includes measures of control of aquatic vegetation that harms human health, since water-related diseases exist in this environment. Although malaria has receded internationally due to the combined chemotherapeutic-insecticidal programs, recently it has resisted both medicines and insecticide control. Active malaria cases in the U.S. were fewer than a dozen before the Vietnam War, but in 1973 the figure was ab out 700, almost all traceable to returning military personnel. The disease could again become prevalent. Other diseases exist whose transmission is indirectly affected by aquatic weed conditions including filariasis, and various trematodiases, especially from the schistosomes, Chinese liver fluke, cattle liver fluke, Guinea worm, giant intestinal fluke, Asiatic lung fluke, and broad tapeworm. Waterweeds also support disease-pest arthropods, i.e., snipe flies, tabanids (horse, gad, deer, and greenheads), Clear Lake gnats, Mayflies, black flies, sandflies, and sewage flies.Ecosystem studies of impounded water research and development of herbivorous fish, and utilization of herbivorous fish in China, are also included in this volume.