• 수산경영론집
• /
• 제23권2호
• /
• pp.53-67
• /
• 1992

It has been recognized, virtually from the time of its inception, that fisheries economics, like other aspects of resource economics, should ideally be cast in capital-theoretic terms. The fish population or biomass can be viewed as a capital stock in that, like conventional or man-made capital, it is capable of yielding a sustainable consumption flow through time. This study is to introduce the optimal control theory which was extended from the theory of calculus of variations into the study of former static theory of fisheries economics started by Gordon (1954). The optimal control theory eliminated the inadequacies of the classical techniques to a large extent. From this point of view, this study, on the base of Schaefer model, summerizes most of major results achieved so far, but does so in a manner such that the links with capital theory are made transparent. This study explores two sets of problems. The first concerns the optimal approach to the equilibrium stock, i.e. the optimal investment policy. The second set of problems arises from the relaxation of the highly restrictive assumption of autonomy (i.e. the assumption that the parameters are independent of time), then concludes the relaxation of linearity assumption together with the complexities caused by that.

• 한국수산과학회지
• /
• 제57권4호
• /
• pp.380-388
• /
• 2024

This study investigated the sexual maturation of the marbled flounder Pseudopleuronectes yokohamae, a commercially important flatfish species, through monthly sampling from the coastal waters of Pohang in the East Sea of Korea in 2022. We analyzed monthly changes in total length (TL), gonadosomatic index, maturity stage, and 50%, 75%, and 97.5% group maturity based on visual assessments and histological analysis of the gonads. The spawning period was determined to be from December to May. The TL at 50% maturity was 26.4 cm for females and 24.8 cm for males. These findings provide a basis for developing resource management strategies for Pleuronectidae.

• 수산경영론집
• /
• 제1권1호
• /
• pp.19-68
• /
• 1970

This is a study of a long term project to encourage the Korean fishing industry. It seeks to supply a sound theoretical background in an attempt to liberalize the capital investment of the industry. However, the discussions developed in this thesis are based on, the existing world's fisheries resources, the possibility of their prospective cultivation, and the analysis of the evolution of Korean fisheries and fisheries organization. According to the reasults of the analysis ; out of the prospective world fisheries resources which are estimated at about 200 millions m/t the total yield per year is only about 70 millions m/t (1969), and Korea occupies only 850 thousands m/t. This therefore means that the Korean fishing industry allows much room for further growth. But the purpose of Korea's existing fishing industry organizations is entirely directed toword coastal fisheries and their functions never reache beyond the limit of off-shore fisheries. Thus almost 99% of the fisheries population engage in small scale fisheries along the coast line. The result is that the resource are almost exhausted by such over-exploitation. Being faced by this fact, it is of urgent necessity to modernize the management of fisheries as well as to encourage larger scale management of fisheries industries. This should be accompanied by the liberalization of capital investment. For this purpose this study also recommends the unification or annexation of small organizations to establish larger ones that will function for a larger scale industry. and further this study recommends that, in order to reorganize the existing fisheries organizations, a principle of selection should be applied in the areas of (1) maximum sustainable yields, (2) the possibility of forming an enterprise and (3) the maintenance of organization stability.

• 한국수산과학회지
• /
• 제57권3호
• /
• pp.302-309
• /
• 2024

This study estimates the target strength of anchovy Engraulis japonicus required for studying their distribution and density using acoustics and evaluates the acoustic scattering characteristics of anchovies by frequency using the Kirchoff ray mode (KRM) model. The experiment was conducted on 30 anchovies with 4.7-21.5 cm total length. The maximum TS_cm (Simming angle, 9.1°; standard deviation, ± 13.1°) according to total length was -66.9, -65.2, -64.4, and -63.4 dB at 38, 70, 120, and 200 kHz, respectively. The average TS_cm (Simming angle: 9.1°, standard deviation: ± 13.1°) according to total length was -68.9, -68.8, -69.6, and -70.0 dB at 38, 70, 120, and 200 kHz, respectively. The results of this study provide an important basis for future studies that use acoustics to estimate the target strength of anchovies.

• 수산해양기술연구
• /
• 제60권3호
• /
• pp.244-257
• /
• 2024

Considering the negative impact of IUU fishing on fishery resources and fishery management, a revised approach for estimating risks of the ecosystem-based fisheries assessment (EBFA) of Zhang et al. (2011) was developed that incorporates three components of the IUU (illegal, unreported and unregulated) fishing as penalties. In this study, we introduced ways to develop indicators of IUU fishing suitable for the Korean fishery and apply them to ecosystem-based resource assessment. The indicator for the illegal fishing component was set as the fishing without licenses or permits, and that for the unreported fishing component was set as unreported fishing activities. Indicators for the unregulated fishing component were set as fishing operated by illegal fishing gear, illegal fish capture, fishing operations in prohibited fishing area, and fishing with restrict permits. IUU fishing significantly impacts the stock of target species. Therefore, in this study, the influence of IUU fishing is included in the Species Risk Index (SRI) at the species level, and weights are assigned based on the ratio of the stock, as $SRI={{\sum\limits_j}{\lambda}_j{\cdot}ORI/{\sum\limits_j}{\lambda}_j}+P_f(B_i/B)$. The revised ecosystem-based fisheries assessment method, which considers the impact of IUU fishing, was applied to major fisheries on the south coast of Korea. It is necessary to reduce the non-reporting rate through the expansion of the TAC system and improve the accuracy of statistical compilation. To this end, the electronic fishing reporting system, which is being implemented on all vessels in Korean distant water fishing vessels, should be introduced to the coastal and offshore fisheries as well.

• 한국수산과학회지
• /
• 제57권4호
• /
• pp.364-371
• /
• 2024

We studied the age and growth of anchovies Engraulis japonicus, collected using three different fishing gears (drag net, set net, and bottom trawl) in the South Sea of Korea from November 2020 to October 2021.To determine the age, 344 speciemens were analyzed by reading the otolith sagittal plane. Monthly changes in the growth of translucency at the edge and the marginal increment ratio revealed that annuli in otoliths were fully formed in March once a year. We compared four different types of growth equations, and found that the data set of observed length at age (yearly) as estimated the growth parameter (L_∞ = FL 16.17 cm, k = 0.33/year, t₀ = -1.65) fitted well on the von Bertalanffy growth curve.

• 수산해양교육연구
• /
• 제25권1호
• /
• pp.139-151
• /
• 2013

Recently, in the context of increased interest for marine tourism, Jeju region of South Korea has attractive waterfront space and also has potential requirements for development. The objective of this paper was to analyze the priority for resource development of waterfront in Jeju region. In order to calculate the importance of factors related to the development of waterfront in Jeju area, this study conducted exploratory factor analysis to extract the factors and established the AHP model based on the factors name focusing on a total of 198 tourists. In this study, in accordance with the procedures of AHP analysis, pairwise comparisons were conducted focusing on a total of 15 experts. Especially, difference test between groups (academics and bureaucratic) was conducted. In the 1st criterion for evaluation, 'exploring experience' factor is most important thing and 'facilities & infrastructure' factors were in the following order. In the secondary criterion, AHP analysis showed that experience facilities, environmental management, and absence of residents consciousness were the important factors. In the future time, the results of this research can be utilized as basic data in the aspects of tourism development in Jeju waterfront region.

• 수산경영론집
• /
• 제34권1호
• /
• pp.45-67
• /
• 2003

Main target of fishing policy was enlargement of fishing catches in Korea after 1960s. This has caused sustainable decrease of the amount on the fisheries resource. In the result, fishing managements in Korea have suffered from aggravation of management. In this research, it is estimated the technical efficiency on Korean Off-shore Stow Nets Fishery that was made publication by Farrel in 1957. According to the analysis, Its were excessive to the gap of technical efficiency among Korean Off-shore Stow Nets Fishing boats. The gaps were excessive not only among each fishing managements but also by tonnage class and by region. Then we can recognize we need the change of Fishing Policy. That is, we should change for main target of fishing policy from enlargement of fishing catches to the policy of Price. And we should consider the supply of standard tonnage boats and specialization of fisheries by regions.

• 수산해양기술연구
• /
• 제60권3호
• /
• pp.269-276
• /
• 2024

In response to the global interest and efforts towards reducing plastic use and promoting resource recycling, there is a growing need to establish methods for recycling discarded fishing gear. In Korea, various technologies are being developed to recycle discarded fishing gear, but significant technical and policy challenges still remain. In particular, biodegradable gill nets require a pre-treatment process to separate biodegradable materials from other substances and to remove salt before recycling. Therefore, this study aims to develop a pre-treatment device for recycling biodegradable gill nets and to evaluate the feasibility of recycling them.

• 수산경영론집
• /
• 제41권1호
• /
• pp.129-156
• /
• 2010

Well-deviced buyback programs may be detrimental to achieve sustainable fisheries. However, it is not difficult to find undesirable examples that the result of buyback program have no impact on fish stocks or the sustainability of the fishery. This paper discusses the problems and policy directions for successful restructuring of Korean marine fisheries through comparative analysis of selected cases from five main countries including Japan, Norway, Italy, Taiwan and Australia. From the analysis, this study demonstrated that Korean buyback program just pursue the reduction of boat number but passed over alleviation of the real ability in fishing industry. Although there were clear decrease of fishing effort in a certain parts of fisheries and some evidences of advancement in efficiency, it seemed hard to continue these effects because the Korean policy lacks consistency and coherence of systematic restructuring. To summary, four things are recommended for successful application of Korean buyback program; first is to establish the obvious goal of the program, second is to introduce downsizing in both fleet capacity and engine power, third is to conduct other management tools simultaneously to help resource restoration, and last, but not the least is to induce voluntary participation of fishermen providing opportunity to pursue their mutual interest.