This study examined the operational characteristics and fishing performance of an offshore pot fishery targeting swimming crabs (Portunus trituberculatus) to identify key issues and proposed strategies for improving efficiency and fisher safety. Analysis was based on approximately one year of fishing logbook data recorded by a pot fishing vessel. The total annual catch amounted to 30,084 kg, with the highest catch per unit effort of 0.07 kg per trap observed in autumn at depths of 20–25 m. No crabs were caught below 15℃ while the peak catch occurred at around 25℃. Catches were geographically concentrated in the mid-northern West Sea, especially near Taean and Boryeong. Economically important bycatch species, including sand crabs, octopus, and turban snails, exhibited distinct spatial distributions. An average of 1,996 traps were deployed per operation with a low loss rate of 1.6 traps. Based on field-level observations, this study proposed the development of automated or semi-automated equipment, such as bait cutters, automatic mainline arranging devices, pot-hauling and separation systems, chilled water tanks for sorting, and automated unloading systems. These technologies are expected to reduce labor demands, improve safety, and enhance the overall operational efficiency of the pot fishery.

In this study, factors such as improvement of a fishing process and safety, reduction of the labor force and headcount and development of the automation technology for offshore (eel and crab) pot fishing vessels were analyzed. A questionnaire survey was conducted to analyze and select the key factors using independent/paired sample t-test and correlation analysis, and a living lab was operated with ship owners, skippers and experts to discuss practical needs of the site. From the result of questionnaire survey and field requirements, it was possible to understand the level of awareness of ship safety, general safety equipment, fishing work process and fishing safety equipment from the point of view of the field. In addition, there were differences in the measurement results of each items because the working environment and experience were different according to the position of the ship owner and the skipper. The results of the questionnaire survey and various perceptions of field stakeholders were reflected when analyzing the fishing system and fishing process to choose the development equipment applicable to the field. From the analysis results, the selected development equipment based on the fishing equipment and process currently in operation are pot washing device, catch separation and fish hold injection device, length limit regulations and bait ejection device after use, automatic main line winding device, bait crusher, automatic (crab) pot hauling separator and so on.

The change of fishing power index was analyzed to identify the development of the vessel and gear technology that may improve the fishing efficiency of the offshore conger eel pot fishery from 1980s to 2015. Gross tonnage per fishing vessel was rapidly increased annually. The standard of pot was maintained, but the number of pot used rapidly increased by using conger eel pot hauling devices, carrying and loading devices, main line hauler, casting devices and slide type pot. Fish finder system to identify fishing ground information and the conger eel pot hauling devices were modernized, and supply rate was also increased. Therefore, the relative fishing power index in the offshore conger eel pot fishery increased from 1.0 in 1980 to 1.3 in 1990, to 1.8 in 2000 and to 2.0 in 2015. The results are expected to contribute to reasonable fisheries stock management of the offshore conger eel pot fishery.