• The Journal of Fisheries Business Administration
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• v.43 no.1
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• pp.1-9
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• 2012

Based on Clark and Munro's theory of dynamic optimization between fishery resources and production, this study is aimed to take an empirical analysis of optimal production level to the Danish Seine fishery under the sandfish stock rebuilding plan. For empirical analysis, it examined the optimal fish stock size, production and fishing effort levels and it also made an additional evaluation of optimal production changes on main variables by sensitivity analyses. When a 4% of the discount rate is assumed, the optimal sandfish production of Danish Seine fishery would be 3,049 t, and the sandfish optimal stock size is evaluated to be 19,016 t. In addition, the optimal fishing effort is estimated to be 4,368 days. Accordingly, to achieve the optimal production level, current fishing efforts should be reduced while the fish stock size should be increased up to the optimal level.

• Ocean and Polar Research
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• v.25 no.3
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• pp.331-345
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• 2003

The fishing ground surrounding Wangdol-cho is not only overexploited by the littering of dilapidated fishing net and equipment, but also by fishermen's overfishing, surpassing optimum fisheries resources. In addition, increasing fishing efforts (number of fishing vessel and fishing net, etc) contribute to the deterioration of fishing ground, and it is urgently required that schemes to tackle the problems should be taken. To effectively address the problems as such, this paper aims to propose sustainable utilization and management scheme of fishing ground through classification of fishing ground surrounding Wangdol-cho as one area which is less than 50m deep, measuring $13.66km^2$ and the other, permission fishing area of Gill Net fishery, measuring $347.23km^2$. The analysis shows that, for the water area less than 50m deep, implementation from a short-term perspective includes autonomous management fishery by gill net and trap fishery. For the permission fishing area of Gill Net fishery, implementation includes limit on fishing period, real name system of fishing equipment and limit on fishing equipment. Implementation from a medium and long-term perspective includes limit on scuba diving, designation of underwater sightseeing zone, sea farming, facilities of surveillance, adoption of approval system for the permission fishing area of Gill Net fishery and introduction of report system for fishing.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.363-388
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• 2020

The purposes of this study are to not only estimate optimal harvests and efforts using the surplus production methods for Spanish mackerel caught by multiple fishing gears, but provide dynamic optimal fisheries management for these gears using the current value Hamiltonian method. To achieve the above purposes this study uses several models such as Gavaris's general linear model for standardizing fishing efforts, surplus production method for estimating biological and technological coefficients, current value Hamiltonian method for estimating dynamic optimal harvest and efforts, and sensitivity analysis for diagnosing economic influences of these fisheries. As a result, this study showed that Spanish mackerel was overfished by multiple fishing gears based on surplus production method and the current value Hamiltonian method. Also, this study found that when the price and cost proportionally changed, the optimal harvest and fishing effort sensitively responded to the stock level of Spanish mackerel. Next, this study suggested that the multiple fishing gears for Spanish mackerel should reduce unnecessary costs such as operating time or inefficient fuel consumption. Finally, this study provided reasons Spanish mackerel should be included in the TAC system in a view of profit maximization based on sustainable use of the Spanish mackerel.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.303-315
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• 2010

The fisheries resource in waters under the jurisdiction of Korea is being endangered by unlawful fishery. The Korean government exerted great efforts to establish the public order of water, but the number of the exposed unlawful fishing violations has increased for last 10 years. The system to guide fisheries regulatory noncompliance of Korea is limited to the use of fishing guidance patrol boats. For strength of monitoring and surveillance systems, the government needs to phase in Vessel Monitoring System. But there are some studies for that. The defects of present monitoring practice can be drawn from the facts described above. The qualification of the fishery control official one of most important element of fishing control system, is defined as any officer who is charging on fishing. For clear law enforcement the qualification should require considerable experience and knowledge. Korean coast guards have problems on guiding unlawful fishing violations because of the absence of administrative authority by comparison with the fisheries guiding officer, who has both authorities on administration and jurisdiction. To draw some judicial problems this research presents a analysis on the fishing control system. The research suggests the improvements to compensate the defects.

• The Journal of Fisheries Business Administration
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• v.17 no.1
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• pp.1-17
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• 1986

Since the middle of the 70s, the countries with the marine resources declared the exclusive water zone of two hundred miles. As a result, our country lacked many foreign fishing grounds. This awakened our perception of fishing grounds. The fishing ground is an important factor in the economical effectiveness of fisheries. The fishing ground must have the following basic conditions. 1. It must be the place the fishery resources inhabit and wander. 2. Their catching or aquaculturing must be possible by the technical methods. 3. It must have economic worth in the management. The fishing ground that achieves the above basic conditions is affected by the following factors. This is the factor of the fishing ground location. A. Natural factor 1). Suitable climate 2).Abundant resources 3). Good quality of the sea-bottom 4). Not to be pollutted area B, Economic factor 1). Be adjacent to fishing port and fisheries market 2). Good working conditions 3). Be abundant of economical resources C. Social factor 1). Be possible to work legally 2). Be permitted in the political relations 3). Be acquainted with the customs of foreign countries The fishing ground location is mainly affected by the natural factor of the above factors. The abundance of resources depends on the natural resources. The resources in the fishing ground have the cycle of developing period, maturing period, and decaying period according to the fishing efforts. The point that we sustainably yield the maximum of fishery resources is the changing point of maturing period and decaying period. We call this point MSY, so the resources of fishing ground should be managed by the MSY. Therefore, when we select the fishing ground location. We should judge the natural factor, the economic factor and the social factor synthetically according to the situation and environment, so we can achieve the efficient management.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.333-342
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• 2018

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 is aimed to estimate optimal fishing effort of giant octopus by combo fishing which uses longline in Gangwon with statistical data. The result showed that current fishing effort is 28% higher than $E_{MEY}$. Unit fishing cost for each voyage will be 27% lower and unit fishing profit will be 17% higher than the current situation when the fishing effort meets $E_{MEY}$. Although current fishing effort is similar to the $E_{MSY}$, current catching is 16% higher than MSY and 22% higher than MEY.

• The Journal of Fisheries Business Administration
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• v.33 no.1
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• pp.1-18
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• 2002

The observer program is being utilized In various fishing areas and fisheries internationally and nationally due to the its expected effectiveness in fisheries management and the collection of bioeconomic data necessary in fisheries management policy. The timely gathered data by observers play substantially a major role in decision-making fisheries policy such as the change in management measures, the application of season closure and area closure and etc. The expected effectiveness of the observer program In fisheries management, generally mentioned, is that it would lead to the increase in stock size from which the level of harvest would consequently increases. This study is aimed to analyze this tentatively expected effectiveness of the observer program in fisheries management. The changes in stock size and the level of harvest over time are analyzed under the observer program assuming the fishermen bear the cost of the observer program by investigating the change in fisherman's fishing activity under the observer program and by combining this changed activity with the biological model. The level of fishing efforts of fishermen was decreased from the results of the increase in fishing cost caused by the observer cost and the decrease in catchable stock size restricted by observers. This reduced level of fishing efforts enables stock size to increase over time and therefore, the expected level of harvest increases as time goes on. Another benefit under the observer program is to reduce management costs from the fact that fishermen are responsible for the cost of the observer program and the avoidance cost of fisherman responding to the fisheries regulation could be eliminated from the surveillance of observer. Therefore, it may possible to accomplish the cost-efficient fisheries management policy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.386-393
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• 2016

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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.64-69
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• 2005

In spite of many efforts, in the design of high speed fishing vessel the sea-keeping performance improvement without neglection of resistance-propulsion performance by hull form itself has its limitations. In this paper, the development of sea-keeping improving appendage pitching and trim improver for high speed planing hull on behalf of the hull form of fishing vessel has been introduced. The developed appendage verified its effectiveness in the full scale test and also has been proved the better resistance performance in the model test and full scale test.

• Journal of Fisheries and Marine Sciences Education
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• v.5 no.2
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• pp.110-118
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• 1993

A squid gill-net fishing vessel Jayueoroho which was being insured ITC-Hulls and was laid up long period illegally under the condition of unmanned in the Pert of Kamcheon. On 30, March, 1993, the fishing vessel moved out toward the high sea by assistance of two tugboats, 12 miles southeast from Teajongdae, to discharge sewage. At that time the shipowner, the skipper, chief engineer and two labourers were boarding, and a fire was broken out by electric leakage at sea. For all their efforts of fire-fighting operation the fishing vessel foundered with explosion. In this case, she had been breached the warranties of legality, especially Korean maritime acts concerned, and the warranties of seaworthiness(MIA 39(5)) as attributable cause because of unmanned on board by wilful misconduct of the insured. Therefore it is prima facie evidence that the insurer is not liable for any loss attributable to the wilful misconduct and breach of warranties of the insured in MIA 1906.