Stock assessment of the ribbonfish, Trichiurus lepturus Linnaeus, from the Indian waters

The fishery of the ribbonfishes and population of the species Trichiurus lepturus Linnaeus were studied from the all-India data collected during 1971-89. The last five years were the most productive with an annual average catch of 79 220 tonnes, contributing 4.5% of the total fish catch and exhibiting an increase of about 48% over the 1970-81 period. This increase in the landings was attributed to the increased exploitation by trawl nets in states like Gujarat and Maharashtra. Trawl net contributed about 50% ofthe total catch. About 75% of the catch came from the west coast and the rest from the east coast. In the west coast the peak fishing season was in the fourth quarter except in Kerala where it was in the third quarter. In the east coast also, peak season was in the fourth quarter in the northern states and in the third quarter in the southern states. The total instantaneous mortality (Z) rates were estimated as 3.15 and 3.71 for the east and west coasts respectively by length converted catch curve method. By Jones' cohort analysis they were estimated at 3.32 for the east and 3.77 for !he west coasts.