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

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 tnet-1, with an average catch of 4.72 tnet-1. An LPS catch per power ranged from 3.38 to 37.84 kg(netkW)-1, with an average catch of 16.96 kg(netkW)-1. However, the catch per net of LFN was from 49.40 to 451.49 kgnet-1, with an average catch of 179.87 kgnet-1. An LFN catch per power was from 0.22 to 2.05 kg(netkW)-1, with an average catch of 0.77 kg(netkW)-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 number of nettings and the fishing zones. While for LFN, the factors were the shooting frequency and the net length.