Giant pacific octopus, Enteroctopus dofleini, is a large mollusk distributed in the East Sea of Korea. In this study, the catch status of giant pacific octopus by drift line fishery and the effect of sea temperature on fishing ground were investigated in Goseong-gun, Gangwon-do, which is the central coast of the East Sea. The average catch of giant pacific octopus in Gangwon-do was 1,570 tons over the past ten years, and it accounted for 21% in 2008 and 44% in 2021 compared to the total catch in the East Sea during the same period. Such data indicates that the catch in Gangwon-do has recently increased. In this study area, giant pacific octopus weighing 1.1-5.0 kg dominated accounting for 56% of the total individuals, and followed by those weighing 1 kg or less. However, the ratio of catch of giant pacific octopus over 5.1 kg tended to increase in 2021, which is thought to be related to the sea temperature that affected the fishing ground. The main depth of fishing ground was from 21 m to 50 m in this area and fishing grounds were widely distributed throughout the season except summer. Fishing ground was formed with the conditions of bottom sea temperature under 10℃ and was diminished by moving of giant pacific octopus to deeper depth with conditions of bottom sea temperature over 18℃.

In order to understand basic data for improving the fishing system and fishing vessel structure in coastal improved stow net fishery, a questionnaire survey and on-site hearing were conducted from May 10 to June 11, 2019 to analyze opinions on the improvement of operation status and fishing vessel structure. The questionnaire survey consisted of ten questions on the operation status of coastal improved stow net fishery and six questions on the improvement of fishing vessel structure, and the results of each question were analyzed by the region, the captain’s age, the captain’s career and the age of fishing vessel. As a result of analyzing opinions on the operation status of the coastal improved stow net fishery, it was found that the average time required for casting net was 32.8 to 33.0 minutes and that the average time required for hauling net was 41.0 to 42.2 minutes which took 10 to 12 minutes more than for casting net. The most important work requiring improvement during fishing operation (the first priority) were ‘hauling net operation,’ ‘readjustment and storage of fishing gear,’ and ‘fish handling’ and the hardest factor in fishing management were in the order of ‘reduction of catch,’ ‘labor shortage’ and ‘rising labor costs.’ The most institutional improvement that is most needed in coastal improved stow net fishery was an ‘using fine mesh nets.’ Most of the respondent to the questions on the experience in hiring foreign crews was ‘either hiring or willing to hire foreign crews,’ and the average number of foreign crews employed was found to be 2.3 to 2.4 persons. The most important reason for hiring (or considering employment) foreign crews was ‘high labor costs.’ The degree of communication with foreign crews during fishing operation were ‘moderate’ or ‘difficult to direct work.’ The most important problem in hiring foreign crews (the first priority) was an ‘illegal departure.’ As the survey results on the opinion of structural improvement of coastal improved stow net fishing vessel, the degree of satisfaction with fishing vessel structure related to fishing operation was found to be somewhat unsatisfactory, with an average of 3.3 points on a five-point scale. The inconvenient structure of fishing vessel in possession (the first priority), the space needed most for the construction of new fishing vessel (the first priority) and the space considered important for the construction of new fishing vessel (the first prioprity) was a ‘fish warehouse.’ The most preferred equipment for the construction of new fishing vessel were ‘engine operation monitoring’ and ‘navigation safety devices.’ The average size (tonnage class), the average horse power and the average total length of fishing vessel for proper profit and safety fishing operation was between 13.8 and 14.0 tonnes, 808.3 to 819.5 H.P. and 23.4 to 23.5 meters, respectively. The results of the operation status of coastal improved stow net fishery and the requirement for improving the fishing vessel structure are expected to be provided as basic data for reference when we build or improve the fishing vessel.

Interviews and boarding surveys were conducted in order to understand the actual usage of octopus pot in the coastal composite fishery in Jeollanam-do. According to the results of the interviews conduced by visiting the areas (Goheung, Yeosu and Wando), the number of octopus pots per nine-ton vessel were 30,000-80,000, and the number of daily usage pots were 7,000-10,000. The number of octopus pots per four-ton vessel was 40,000, and the number of daily usage pots were 4,000. As a result of the survey on two octopus pot fishing boats (9.77-ton and 4.99-ton) in Yeosu area, the daily catch weight of 9-ton class vessel was the minimum of 66.9 kg and the maximum of 159.6 kg. The daily catch weight of the four-ton class fishing vessel was from 31.3 kg to maximum 85.6 kg. The average number of octopus pot used per day in the nine-ton class vessel was 6,821 (the minimum of 6,031 and the maximum of 7,697) and 3,181 (the minimum of 2,282 and the maximum of 3,878) in the four-ton class vessel.

A large number of divers that are engaged in a diving apparatus fishery (DAF) have been experienced a decompression sickness. This study has two purposes. One is measurement of the diving patterns and respiration rate. The other one is to research the institutional improvement plan of the DAF. In the experiments, the diving depth, the diving time, the total ascent time and the ascent rate were about 12.4 m, 22 min, 28 s and 28.1 m/min, respectively, in Tongyeong. In the case of Geoje the diving depth, the diving time, the total ascent time and the ascent rate were about 20 m, 64 min, 17 min and 1.3 m/min, respectively. In a questionnaire survey, the diving depth was 20~29 m (56.4%) in Tongyeong and Geoje, the diving time was 50~59 min (42.9%) in Tongyeong and 70~79 min (35%) in Geoje and all of the divers experienced decompression sickness. In the investigation related to a institutional issue, both of the diving apparatus fisheries had adopted the share system. And the laws and the system for the safety of the divers were not enough in Korea. This study suggests that the license and the diving time for diver of the DAF are needed and diver protection for decompression sickness is needed in the law. And the wage payments should change from full sharing to partial sharing included a regular pay to enhance the safety of the divers.

The aims of this study are to access the status and problems and draft possible solutions of Korean trawl fishery in New Zealand sea. The main target fish species for Korean trawlers in this sea were barracouta, blue mackerel, hake, hoki, jack mackerel, ling, oreo, orange roughy, southern blue whiting, spiny dogfish, squid and silver warehou. The Korean trawl fishery are suffering from a supply of seaman, continuous increasing coast of the counter partner, repair of vessel and seaman supply. It may be useful for getting over these difficulties to build a new trawler with a automatic operation system.

To investigate the catches of jack mackerel fishery, a series of fishing experiments was conducted in the high seas of the southeastern Pacific Ocean (30˚S-38˚S, 82˚W-95˚W) during the period of 9 August to 18 December, 2003 by commercial fishing vessel and research vessel. The number of 205 tows fishing was carried out in the southeastern Pacific Ocean. The total catch was 1,988 ton and CPUE was 2.4 ton/hour. CPUE showed high values in the frontal zone during the survey. Main target species caught from the experimental fishing were the jack mackerel, Trachurus murphyi (98.1%) and chub mackerel, Scomber japonicus (1.9%) as bycatch. Body length of the jack mackerel was different between female and male. The high mean catch per unit effort of jack mackerel was showed when the fishing ground of jack mackerel fishery was over the 110˚W in the southeastern Pacific Ocean. But the fluctuation of the catch per unit effort in the western part of fishing ground was not matched with those year. Reliable physical and oceanographical information will be useful for the efficiency of fishing activity. According to the result of monthly movement of center of fishing ground, the fishing activity of jack mackerel fishery was performed northward in the southeastern Pacific Ocean as time passes.