During the years 1981-1986, an estimated annual average catch of 25 tunas were landed by gill nets operated from commercial mechanized vessels from the Kasimedu landing centre, Madras, where all the catches from mechanised. Vessels land. This catch was obtained by expending annual average of 18,209 fishing hours with a catch rate of 1.4 kg/hr. It was observed that the maximum catch and catch rate were during April. Of the five species that constituted the fishery, Euthynnus affinis (79.9%) dominated the catch followed by Katsuwonus pelamis (12.4%), Thunnus albacares, Auxis thazard and Sarda orientalis formed the rest of the catch. The von Bertalanffy parameters of growth were calculated for E.affinis by length frequency method and the values were compared with those obtained for the species from other regions.

Based on the data collected during the  6 year period, Maximum  sustainable yield and optimum fishing effort were estimated for tunas in the commercial fishing grounds off Madras (12.80/4C, 5C and 6C, 13.80/1C, 2C, 3C and 4C). The MSY was 27 tonnes and optimum fishing effort was 17,826 hours. These estimations reveal that the tuna stock of the inshore area off Madras may not stand to any further increase in fishing effort.