Water, one of the most important natural resources, is often adversely affected by aquatic weeds, resulting in critical problems in agriculture, navigation, irrigation, pisciculture and public health. The menace of water weeds is reaching alarming proportions in many parts of the world. The problem is global, but more pronounced in tropical and subtropical zone, where warm weather supports profuse growth of aquatic plants. In India, large irrigation projects have been reported to be adversely affected by profusely growing aquatic weeds.

The scientists and technologists, therefore, gradually changed their destructive attitude towards these apparently troublesome plants, and tried to turn them to productive use. Limited research so far being carried out in this line, has yielded encouraging results. It has been found that aquatic weeds constitute a crop of great potential value. In that, it is a highly productive crop, requiring no tillage, fertilizer, seed, or cultivation. The plants have been found to have potential for use as animal feed, human food, soil additives and fuel. 

This monograph is a humble attempt to summarize, to some extent, the information gathered so far by the international scientists on aquatic weeds and their economic importance.