Inland Fisheries

5.1.6 Fisheries production potential of estuaries of India

Various estuarine systems spreading over 14.22 lakh hectare form an important component of the fisheries resources of the country. The fisheries of estuaries are above subsistence level and contribute significantly to the production. The average fish yield varies from 45 to 75 kg per ha. Estuarine fishery is the mainstay during the monsoon season when fishing in the sea, because of turbulent conditions and stormy weather, gets suspended. Food chains in the estuaries differ from the open sea in several aspects. A greater part of the organic production in estuaries is controlled by larger plants (macroalgae, mangroves, etc.) rather than phytoplankton. As consumers of the organic matter, zooplankton become less important than the suspension and deposit feeders. Organic detritus forms a major source of food for the estuarine communities. Nearly 49% of Indian marine fish catch originate from estuaries which provide indication of the dependence of marine species on estuaries in early life history.

The National Commission on Agriculture stated that “under the term estuarine fisheries is included the fishery output from the mouth of rivers, the large brackish water lakes, the innumerable tidal creeks and backwaters along the coast and the coastal canal system. Fishes of brackish water are usually marine which can tolerate wide salinity changes and are called euryhaline. These are clupeids, mullets, catfishes, perches and prawns. Mugil cephalus forms a large part of the estuarine fishery. In addition, species that are not of commercial value also contribute to the fishery of brackish water. They include gar fishes, halfbeaks, eels, flatfishes, sharks, rays and oysters. Some migratory fishes that migrate to freshwater from sea or vice versa are also included. They include Tenualose (Hilsa) ilisha, Polynemus spp, Pama pama, Tachysurus spp, Pangasius spp and the prawn, Macrobrachium spp.