The probable loss of breeding grounds due to submergence could be disastrous (though the reservoir could become a new home), an aspect which needs to be studied. Even the existing breeding grounds have not been identified to date. We cannot predict possible impacts on other aqautic fauna, and on the aquatic and riverine flora in the absence of comprehensive ecological surveys.
Importantly, fish provide a major protein component of the diet of all the tribal people living along the river in the summer months, in addition to being the source of livelihood for many other people. Once the reservoir is formed, fish populations will fluctuate considerably, increasing at first, but stabilizing later or even suffering a long-term decline (Goldsmith and Hildyard 1984). What will happen to the people dependent on fish for their livelihood and nutritional needs in the interim? Even the fish farming programmes proposed by the project authorities will take a long time to come to fruition, and may well be cornered by powerful outsiders to the area. The experience of Bargi Dam, the first dam to be completed on the Narmada River, is relevant here. People who were resettled from the submergence zone were denied the right to, fish in the reservoir, with the fishing contracts being auctioned to the highest bidder instead of being awarded to the fishing cooperative set up by the government. The Bargi oustees have made several strong protests regarding this issue in the last year or so.
Studies are supposed to have been completed for the entire submergence area, and the proposed reservoir. Compensatory measures for the loss of aquatic biodiversity are not yet completely planned out, but the major suggestions include "selective stocking of the reservoir with a combination of indigenous fish species; research into and instigation of pilot projects for the artificial propagation of important species; setting up of an Interstate Fisheries Development Board to control and monitor fisheries exploitation and to coordinate research and development; monitoring of potential pollution sources", and others (NCA 1993).
What is instructive is that the focus of the studies and proposed measures is exclusively fish. Among fish, too, the emphasis given in various official reports is on commercially important species. There appear to be no moves to avert or minimise the negative impacts on other aquatic species, which is a serious flaw considering that fish fauna make up only a small part of total aquatic biodiversity. Once again, there will be an inevitable loss due to submergence.