Effectiveness of Tubular Lamp on Floating Bamboo Lift Net Fisheries.

Abstract

The objective of this research was to determine the effectiveness of tubular lamp construction to attract organisms in floating bamboo lift net and the best time interval to operate floating bamboo lift net. Lamp construction consisted of standard lamp, lamp with reflector, underwater lamp, and surface lamp without reflector as control. The research was started while floating lift net using lamps without reflector at 07.00 pm to 10.00 pm; the lamp with reflector between 10.00 pm to 01.00 am; and underwater lamp between 01.00 am to 04.00 am. The lamp operation series was changed at each floating bamboo lift net operation. Every lamp construction was operated 1-3 times in a time interval. Collected data were light illumination of each lamp construction in water, and weight and species composition of caught organisms. Data were showed on tables and graphs. Data analysis used descriptive comparative methods. The result of this research indicated that tubular lamp construction with reflector and underwater lamp had the best distribution light on floating bamboo lift net operation. Light penetration of both lamps were about 9 and 10 m, respectively. The standard tubular lamp spread in all direction with maximum light penetration of 6 m. Time interval between 07.00 pm to 10.00 pm and 01.00 am to 04.00 am were the effective time to catch organisms. Both time intervals produced 119.8 kg and 125.2 kg. While, time interval between 10.00 pm to 01.00 am was only 41.3 kg. The organisms that was caught by floating bamboo lift net consisted of 4 positive phototaxis organisms and 4 predator organisms. The positive phototaxis organisms were mackerel, indian mackerel, anchovy, and trasi shrimp. While the predator were hairtails, silver pomfret, cuttlefish, and little tuna. Lift net with underwater lamp caught heavier organisms than those tubular lamp with reflector and standard lamp, i.e. 151,7 kg, 95,9 kg and 65,6 kg in weight.