Squid is one of the important fisheries resources in Korea. Therefore, squid has been designated and managed as a target species of total allowable catch (TAC) since 2007, but the catch amount is gradually decreasing. The analysis was conducted to identify the change of relative fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore squid jigging fishery from 1960s to 2010s. Gross tonnage per fishing vessel increased with the increase in size until 1990, but then gradually decreased to 41.0 tons in 2000 and 37.1 tons in 2010. The illuminating power (energy consumption) by fishing lamps increased to 180 kW in 2005 and stabilized to 120 kW in 2015. Jigging machine started to be supplied to fishing vessels from the early 1970s, and fish finders began to be supplied in the early 1980s and gradually increased. Therefore, the relative fishing power index in the offshore squid jigging fishery increased from 1.0 in 1980 to 1.1 in 1990, to 3.5 in 2000 and to 2.5 in 2010, but the increment rate slowed down gradually. The results are expected to contribute to reasonable fisheries stock management.

The aim of this study is to investigate influence of moon light to the fishing of squid jigging fishery in the southwest Atlantic Ocean based on analyses of date taken from 127 vessels in Falkland fishing ground by squid jigging fishery from 2010 to 2015. Catch and CPUE were analyzed between the new moon and full moon phases. Catches of the new moon phase were higher than those of the full moon phase by 7.6% and CPUE expressed in mt/day-vessels and mt/line-day were also higher by 18.2%, 18.2% respectively. However, as a result of statistical analysis at a significance level of p ＞ 0.05, no significant statistical differences in catch, mt/day-vessels and mt/line-day were found between the new moon and the full moon as a result of statistical analysis at a significance level of p ＞ 0.05.

The fuel cost of fishing lights for squid jigging fishing vessels takes about 30% of total fishing costs and over 65% of total fuel costs, which indicates the necessity of development of cost-reducing and high efficient fishing light system. This study aimed to analyze the economic effectiveness of LED fishing light systems in combination with metal halide lamp for the squid jigging fishery. Analytical results showed that the level of fishing profits of vessels using LED lights could be different with those of vessels using metal halide lights. That is, when a fuel cost could be reduced by 30%, fishing profits of vessels using LED lights might be the same as those of vessels using metal halide lights, and fishing profits of vessels using LED lights could be higher than those of vessels using metal halide lights when a fuel cost could be reduced by 50%.

To investigate the catches of squid jigging fishery, a series of fishing experiments was conducted in the high seas of the Northwest Pacific(40˚-43˚N, 150˚-155˚E) during the period of 1 August to 22 October 2005 by commercial fishing vessel. The number of 142 test fishing was carried out in the Northwest Pacific during 83days. The total catch were 47,524kg as 4 squid species and CPUE was 8.9kg/line·day. CPUE showed high values in the frontal zone during the survey. Main squid species caught from the experimental fishing were the neon flying squid, Ommastrephes bartrami(96.8%) and the boreopacific gonate squid, Gonatopsis borealis(3.2%). Dorsal mantle length of the neon flying squid were increased by the time and increasing of the hook size. Loss rate of the neon flying squid in the water showed the highest values in 28.2% compare to the others. And the loss rate of the front roller and in the air were 1.1% and 1.0%, respectively.