Study on the Capacity of Fishing Lamps and Catch per Unit Effort of Stick-held Net in waters off Northern Taiwan

Abstract

The torch light net fishery is one of the most important fisheries in the northern waters of Taiwan. The fishing season is from May to October. The species composition includes the Loliginidae, Scomber, Carangidae, Euthynnus, Auxis, Trichiuridae, Etrumeus teres, Spratelloides gracilis, Engraulis japonicus (immature and mature), and Thamnaconus. In recent years, however, many disputes over the torch light net fishery have led to demands for adequate rational management mechanisms. Nonetheless, research data on the capacity of fishing lamps are scarce. Herein, results are presented of 84 fishing tests with different-capacity fishing lamps conducted in waters between the capes of Pitou (Pitouchiao) and Fukuei (Fukueichiao) by a chartered fishing boat, the Lin-chang (19.94 GT, 400 HP), from June 19 to October 28, 2003. Fishing data from 15 sampling boats at the fishing ports of Chinshan, Wanli, Keelung, Ruifang, and Aodi were also collected during the same period. Data from fishing with 0, 20, 40, 60, 80 and 100 Kw of deck fishing lamps and stick-held nets were analyzed based on Duncan’s multiple-range test. It was found that the maximum catch per unit effort (CPUE; 117.31 ± 126.29 kg/haul) was obtained when 80 Kw fishing lamps were used, which was proven by Duncan’s multiple-range test at a two-tailed significant level of 5% (F = 2.60, p > 0.0314). No significant differences were found among the light capacities of each kind of fish species and their body lengths. Further results from the 15 sampled boats, which used < 10, 11~30, 31~50, 51~70, 91~110, and 151~170 Kw of fishing lamps and stick-held nets, indicated better CPUE values were obtained in the sampled boats using 51~70 Kw fishing lamps. Their CPUE values were about 709.31 kg/boat-day. Fishing results of sampled boats that used fishing lamps of higher than 80 Kw did not significantly increase with the higher wattages used.