The present status of ribbonfish fishery in India

Abstract

The ribbonfishes, of the family TrichiurkJae, an Important group of food fishes in India, registered an average annual catch of 53.475 tonnes during 1970-81. In this period, forming 4.25% of the total marine fish catch, thsy formed the 7th exploited fish group in the order of predominance. There are 8 known ribbonfish species in India (an identification key to the species is given in the beginning of thearticle) The information available on the various aspects of biology of each of these species is summarised, which clearly indicates that while our knowledge on the biology of Trichiurus lepturua, Lepturecanthus savale, Eupleurogrammus nwticus and Eupleurogrammus glossodon is considereble, we know little about the other species. Traditionally, the ribbonfishes are caught by boatseines, shoreseines, bag nets and gill nets, operating from nonpowered country crafts. But, during the last two decades, the small mechanized vessels (10-15 m long, with 15-100 hp engines) that are operating otter trawls, too, are increasingly landing ribbonfish. The fishery is confined to the depth-zone usually shallower than 50 m. T. lepturus, the most widely distributed, forms the mainstay of the ribbonfish fishery, contributing to the bulk of the landings along almost all our coastline. Data on spatial and seasonal variations in abundance, size and age composition in the commercial catches and diurnal movements and depthwise distributions of shoals of this species are therefore reviewed. Stock assessment studies show that, in the shelf region from Ratnagiri on the west coast round to Gulf of Mannar on the east, there had been an average standing stock of 67,200 tonnes of ribbonfish (mostly L Lepturus) in 1972-75, which is about 4 times what was actually landed from the region during the period. It therefore follows that a doubling of the catch will not adversely affect the stock in the region. Studies on the population dynamics of T. lepturus from the Kakinada area during 1967-71 has shown that the fishing mortality and the exploitation rates are low, at 0.3 and 0.17 respectively. The average annual stock and average standing stock along the Andhra and Tamil Nadu coasts are estimated at 85,000 and 48,000 tonnes, respectively, for T. lepturus, against an estimated annual average catch of 14,400 tonnes during 1967-71. It thus appears that the stock of T. lepturus along the east coast also is likewise underfishad, The need for extension of fishing operations into the Exclusive Economic Zone with larger vessels, equipped with suitable gears like bottom and pelagic trawls, is emphasized- Suggestions on future lines of research are given.