中、西沙海域2种灯光作业渔船的捕捞特性及其技术效率分析

Comparative analysis on fishing capability of two light attracting commercial fishing methods around Zhongsha and Xisha Islands sea areas,South China Sea

根据2008年渔港抽样调查数据,应用随机生产边界法和方差分析对中、西沙海域作业的灯光围网船和灯光罩网船的捕捞能力进行了研究。结果表明,灯光围网渔获物以颌圆鲹(Decapterus lajang)、蓝圆鲹(Decapterus maruadsi)、扁舵鲣(Auxis thazard)、羽鳃鲐(Rastrelliger kanagurta)、鲔(Euthynnus alleteratus)和大目金枪鱼(Thunnus obesus)为主,灯光罩网主要渔获种类为柔鱼(Ommastrephes spp.)、蓝圆鲹和颌圆鲹。灯光围网船每网次产量1.00～12.52t,平均4.72t,单位功率网次产量3.38～37.84kg.kW-1,平均16.96kg.kW-1。灯光罩网船单船网次产量49.40～451.49kg,平均179.87kg,单位功率网次产量0.22～2.05kg.kW-1,平均0.77kg.kW-1。灯光围网船技术效率34.7%～91.7%,平均69.4%。灯光罩网船技术效率50.4%～92.1%,平均78.2%。方差分析表明,影响灯光围网产量的主要因素是投网次数和作业渔区数;影响灯光罩网产量的主要因素是投网次数和网衣长度。

Based on the data sampled from some landing ports of Guangdong and Guangxi provinces in China in 2008, the stochastic production frontiers （SPF） and variance analysis were used to analyze the fishing capacity of the light attracting purse seining （LPS） and falling net （LFN） fishery around Zhongsha and Xisha Islands sea areas. The results showed that the main catch species of LPS were horse-mackerel （Decapterus lajang） , Japanese scad （D. maruadsi） , frigate tuna （Auxis thazard） , Indian mackerel （Rastrelliger kanagurta）, Atlantic black skipjack （Euthynnus alleteratus） and juvenile bigeye tuna （Thunnus obesus）. While for the LFN catch, squid, Japanese scad and horse-mackerel （D. lajang） accounted for most of the main catch species. Catch per net of LPS ranged from 1.00 to 12. 52 t·net^-1 , with an average catch of 4. 72 t·net^-1. An LPS catch per power ranged from 3.38 to 37. 84 kg·（net·kW） ^-1, with an average catch of 16.96 kg·（net.kW）^ -1. However, the catch per net of LFN was from 49.40 to 451.49 kg.net^-1, with an average catch of 179.87 kg·net^-1. An LFN catch per power was from 0. 22 to 2.05 kg·（net·kW）^ -1, with an average catch of 0. 77 kg · （net·kW） ^-1. The technical efficiencies （Te） of LPS and LFN were 34.7% -91.7% （ average at 69.4% ） and 50.4% -92. 1% （ average at 78.2% ）, respectively. The variance analysis indicated that the main factors affecting the fishing Te of LPS were the num ber of nettings and the fishing zones. While for LFN, the factors were the shooting frequency and the net length.