Dr. Sundaramoorthy, BHARSHA, KDr. Neethiselvan, NDr. Athithan, S2017-06-272017-06-272016-09-08http://krishikosh.egranth.ac.in/handle/1/5810023420The present study was carried out for a period of one year from July 2015 to June 2016 to analyse and document the design, operation and performance of gillnets of Tharuvaikulam, a coastal fishing village of Tamil Nadu. Seven types of gillnets are being operated from Tharuvaikulam, of which, four are drift net types and three bottom set gillnets. Based on the vessel type and number of days per fishing trip, the fishing in Tharuvaikulam was categorized into three types namely, motorized single day, motorized multiday and mechanized multiday. The distance of fishing ground, depth of operation, type of fishing gear etc. vary for each category of fishing vessels. The CPUE was calculated for each category and found to be maximum for mechanized multiday fishing (319.58 kg/day) during the month of June and the minimum (44 kg/day) for motorized single day fishing boats during the month of February. Significant difference was noticed in CPUE values of motorized multiday vs motorized single day and mechanized multiday vs motorized single day fishing categories. The catch composition, size and weight ranges of fishes caught from different types of gillnet were documented for Tharuvaikulam coast. The large mesh gillnet locally called ‘Paru valai’ was recorded with 14 species including two tuna species namely, Thunnus albacares and Katsuwonus pelamis that shared around 63 % in the catch. The catch composition of full beak net had 13 species, of which the targeted full beak species constituted 51.71% of the total catch. The other drift gillnets namely, half beak net and flying fish net operated along Tharuvaikulam coast was recorded with only four and three species in the catch respectively. Bottom set gillnets showed high species diversity in the catch but poor ability in targeting the commercial species. Per day fuel usage for different fishing category of Tharuvaikulam was estimated as 53.3 l, 50 l and 15 l for mechanized multiday, motorized multiday and motorized single day sectors respectively. The carbon emission intensity was calculated high (0.708 kg of CO2/ kg fish) for single day and low (0.104 kg of CO2/kg fish) for mechanized multiday fishing. In addition, the gear loss intensity, bycatch, discards, disturbance pattern of scheduled species and catch quality were studied to estimate the ecosystem effects of fishing by different types of gillnets of Tharuvaikulam. The drift gillnets scored as good, whereas, the bottom set nets were rated as average because of its low target species performance to catch. The present study concludes that the drift net fishing of Tharuvaikulam is well within the guidelines laid out for Responsible Fishing by the FAO, and could be promoted as a model for adoption.ennullThesis