Selection of lamp reflector construction and fishing time of lift net

Abstract

This study aimed to determine lift net’s lamp reflector construction which is able to give highest weight on catch and determine the best fishing time. Three lamp reflector constructions were made of cylinder shape for one construction and cone shape with opening angle α = 62° and 90° for two others. The dimension (øR × HR) for each reflector are 30 × 37 (cm), 40 × 18 (cm) and 40 × 39.62 (cm). Each lamp reflector was being operated by 1 lift net for 15 nights. Total fishing operations were twice per night within interval 07.00–12.00 PM and 00.00–05.00 AM. Results of the catch gave 2 schools of fish which were plankton feeders and predators. Plankton feeders included anchovy Stolephorus spp. 477 kg, mackerel (Rastrelliger spp.) 1934 kg, and malayan half (Decapterus sp.) 15.5 kg. Predators consisted of hairtail (Trichiurus sp.) 982 kg, yellowstrip scad (Selaroides spp.) 29 kg, and giant trevally (Caranx sp.) 26.3 kg. The lift net which operated lamp reflector of α = 90° has the highest catch of 2,307.8 kg, while the lamp reflector of α = 62° has 1895 kg of catch. The one with cylinder shape has 1261 kg of catch.

Keywords

• Cylinder reflector
• Cone reflector
• Lift net