In this study, internationally widely utilized bioeconomic models were used to make a comparison and analyze the effectiveness of red snow crab fisheries management measures. As a specific effect analysis, biological and economic effects of both total allowable catch (TAC) and effort reduction management measures were analyzed simultaneously. Model results showed that the red snow crab biomass would be decreased from 106,000 tons to 73,076 tons after ten years when the TAC is set to and maintained at the current level of 26,000 tons. The amount of biomass would be increased to 125,316 tons when the level of TAC is set to 22,000 tons. In cases of reduced fishing efforts, a 30% decrease from the current level would result in greater biomass and NPV would be also estimated at the highest level. In addition, a sensitivity analysis by market price was conducted to analyze the minimum TAC level of the red snow crab offshore pot fishery. Results showed that the minimum TAC level would be 8,210 tons when the market price increased by 30% and it would be also 15,247 tons when the market price decreased by 30%. Furthermore, results of the sensitivity analysis by fishing cost showed that the minimum TAC level was analyzed to be 13,857 tons when the fishing cost increased by 30% from the current level.

In this study, the Bayesian state-space model was used for the stock assessment of the Blackfin flounder. In addition, effective measures for the resource management were presentedwith the analysis on the effectiveness of fisheries management plans. According to the result of the analysis using the Bayesian state-space model, the main biometric value of Blackfin flounder was analyzed as 1,985 tons for maximum sustainable yield (MSY), 23,930 tons for carrying capacity (K), 0.000007765 for catchability coefficient (q) and 0.31 for intrinsic growth (r). Also the evaluation on the biological effect of TAC was done. The result showed that the Blackfin flounder biomass will be kept at 14,637 tons 20 years later given the present TAC volume of 1,761 tons. If the Blackfin flounder TAC volume is set to 1,600 tons, the amount of biomass will increase to 16,252 tons in the future. Lastly, the biological effectiveness of the policy to reduce fishing effort was assessed. The result showed that the Blackfin flounder biomass will be maintained at 13,776 tons if the current fishing efforts (currently hp) level is set and maintained. If the fishing effort is reduced by 20%, it will increase to 17,091 tons in the future. The analysis on the economic effect of TAC showed that NPV will be the lowest at 1,486,410 won in 2038, 20 years after the establishment of 2,500 tons of TAC volume. If the TAC volume is set at 2,000 tons, NPV was estimated to be the highest at 2,206,522,000 won. In addition, the analysis on the economic effect of the policy to reduce the amount of fishing effort found that NPV will be 2,235,592,000 won in 2038, 20 years after maintaining the current level of fishing effort. If the fishing effort is increased by 10%, NPV will be the highest at 2,257,575 won even thoughthe amount of biomass will be reduced.

This study aimed to analyze the economic feasibility of the reduction of working safety accidents in stow net fishery through the prevention education to fishing crews. The benefit was evaluated by estimating insurance payment amount that was reduced through prevention education. The decreasing rate of working safety accidents was presumed to follow the experience in Japan. The cost was assumed as the cost of textbook development. Results indicated that IRR was estimated to be 79.9% in case of scenario assuming no additional operating costs while IRR was 56.3% in case of scenario assuming 10% additional operating costs. In addition, the economic feasibility would be secured when annual operating costs increased to 274 million won according to the result of sensitivity analysis.

The aim of this study is to analyze the relationship between international oil price as a fuel cost in overseas fisheries and skipjack tuna price as a part of main products in overseas fisheries using monthly time series data from 2008 to 2017. The study also tried to analyze the change of fishing profits by fuel cost. For a time series analysis, this study conducted both the unit-root test for stability of data and the Johansen cointegration test for long-term equilibrium relations among variables. In addition, it used not only the Granger causality test to examine interactions among variables, but also the Vector Auto Regressive (VAR) model to estimate statistical impacts among variables used in the model. Results of this study are as follows. First, each data on variables was not found to be stationary from the ADF unit-root test and long-term equilibrium relations among variables were not found from a Johansen cointegration test. Second, the Granger causality test showed that the international oil prices would directly cause changes in skipjack tuna prices. Third, the VAR model indicated that the posterior t-2 period change of international oil price would have an statistically significant effect on changes of skipjack tuna prices. Finally, fishing profits from skipjack would be decreased by 0.06% if the fuel cost increases by 1%.

This study is aimed to compare stock assessment models depending on how the models fit to observed data. Process-error model, Observation-error model, and Bayesian state-space model for the Korean Western coast fisheries were applied for comparison. Analytical results show that there is the least error between the estimated CPUE and the observed CPUE with the Bayesian state-space model; consequently, results of the Bayesian state-space model are the most reliable. According to the Bayesian State-space model, potential yield of fishery resources in the West Sea of Korea is estimated to be 231,949 tons per year. However, the results show that the fishery resources of West Sea have been decreasing since 1967. In addition, the amounts of stock in 2013 are assessed to be only 36% of the stock biomass at MSY level. Therefore, policy efforts are needed to recover the fishery resources of West Sea of Korea.

This study aimed to analyze the profitability and economic feasibility of hairtail trolling line gear that was developed for the last 3 years (2015-2017). The new fishing gear technology development was accomplished to solve the current problem of fishermen shortage in hairtail targeting fisheries in Jeju region. Results indicated that the profitability of developed hairtail trolling line fishery was estimated to be 36.1 % which would be higher than that of other hairtail targeting fisheries in Jeju region. In addition, as an economic feasibility, the net present value and the internal rate of return of a 20-year cash inflow and outflow were evaluated to be 400.2 million won and 66.9 %, respectively. However, sensitivity analyses of main variables showed that the profitability and economic feasibility would be vulnerable to catch amount and market condition changes.

In order to manage and rebuild fishery resources, the fishing effort should be controlled effectively. Especially in the setting up of the proper level of fishing efforts, economic standards as well as biological standards must be carefully considered to promote the sustainable and economically viable development of fisheries. This study aimed to analyze the optimal economic fishing effort (EMEY) as the most economically efficient one for the Eastern Sea Danish seine fisheries. The results showed that the optimal economic fishing effort (EMEY) of Eastern Sea Danish seine fisheries for blackfin flounder should be reduced by about 27%. That is, reducing fishing efforts up to the level of EMEY could lead to the reduction of fishing costs, thereby resulting in the increased fishing profits.

It is essential to provide good environment for juvenile fish to grow and spawn in order to keep reproduction mechanism of fisheries resources. However, harvesting juvenile fish deprives adult fish of the opportunity to reproduce, thereby changing self-regulating renewable resources into non-renewable ones and preventing sustainable harvesting as well as reducing fishers’ income. We reviewed the catch status of Korea on juvenile mackerel and analyzed how reducing the catch ratio of juvenile mackerel may affect the spawning stock and Korean fishermen's revenue. In addition, we analyzed the problem of caching juvenile mackerel in Korean fisheries and current efforts to protect and reduce the catch ratio of juvenile mackerel in Korea. Furthermore, we suggested future efforts to protect juvenile mackerel. The result of the study showed that reducing the catch ratio of juvenile mackerel from 44.4% to 30.0% would increase fishers’ revenue by 60.6 billion KRW. We suggest the changing of purse seine fishery’s catching methods from night operation to day operation, relocation of fishing vessels to move to other fishing grounds when fishing vessels meet high density of juvenile mackerel, and consumers’ clever choice of consuming adult mackerel in order to accelerate the move toward protecting juvenile mackerel in Korea.

This study aimed to analyze the relationship between catch amount and market price of sandfish for improvement of fishing revenues and effective fisheries management. By estimating the sandfish price function by fishery, the study tried to investigate changes of prices by catch amount as well as changes of fishing revenues by catch amount and price. Results showed that time series data on catch and price were estimated to be non-stationary from unit root tests, but long-term equilibrium relations between catch amount and price were found from a cointegration analysis. Results of regression analyses indicated that the catch amount would have negative impacts on prices of sandfish in both coastal gillnet and danish seine fisheries.