This study analyzed the catch data of Chionoecetes japonicus in the offshore trap fishery from 2009 to 2022 to investigate the spatial distribution changes of fishing grounds in the East Sea. The results showed that the center of the fishing grounds consistently shifted offshore and northward from 2009 to 2020, but moved back towards the coastal areas since 2020. When comparing the catch of C. japonicus from the offshore trap fishery between 2009-2015 and 2016-2022, statistically significant differences were found (p<0.01). Analysis of the center of the fishing grounds revealed that they gradually shifted offshore while the fishing grounds were initially concentrated in the coastal areas of the East Sea. This suggests that the center of the fishing grounds moved offshore and northward as the C. japonicus in the coastal fishing grounds decreased. The shift of the fishing grounds back towards the coastal areas since 2020 is attributed to the increased operational costs due to the soaring fuel prices and the impact of the COVID-19 pandemic, which led to a decline in consumer demand for live seafood consumed in restaurants. Consequently, the offshore trap fishery for C. japonicus shifted their focus from offshore areas, which required higher operational costs due to increased fuel consumption and longer fishing times, to coastal areas, that were relatively less costly. This study is the first scientific results of its kind to investigate the formation of fishing grounds and annual changes in the fishing grounds of C. japonicus caught in offshore trap fishery in the East Sea from 2009 to 2022.

Offshore trap fishery managers have payed in advance to attract excellent fishing crew in the minium grantee lay system. This practice can intensify competition among fishery management bodies and increase the burden of fishery manager about income tax and four social insurance programs. The purpose of this study is to identify the problems of advance payment practice in terms of fishery manager in offshore trap fishery. The main results of this study are as follows. First, under the TYPE 1 model, which is the current wage payment manner, there is a risk that fishery manager will not able to return the prepayment paid in advance when the income of fishery management bodies decrease. Second, the TYPE 2 or the TYPE 3 model which reduces or abolishes advance payment can alleviate the burden of fishery manager relative to the deduction of redemption amount, incentive to induce artificial expenses, income tax and four social insurance programs. In conclusion, advance payment practice in offshore trap fishery is placing a heavy burden on the fishery manager. In order to solve these problems in the future, we need to find solutions through similar case studies.