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.