• Journal of Fisheries and Marine Sciences Education
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• v.14 no.1
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• pp.57-73
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• 2002

Illegal fishing is often cited as a principal cause of the failure of fisheries management, expecially fishing efforts regulations in traditional fisheries management. Usually, illegal fishing problems are perceived to be equivalent to inadequate enforcement, and policy prescription then follow to strengthen enforcement programs. The purpose of this paper is to analyze the illegal fishing behavior relatively recent emphasis on fishing efforts regulations in traditional fisheries management. The analysis focuses on measuring, explaining and developing the effectiveness way of enforcement strategies responding to imperfectly managed fishing efforts regulations through illegal fishing behavior and avoid enforcement fishing efforts measures. A model of fishermen fishing behavior and profit-maximizing decision making is analyzed to determine optimal fishing at individual fisherman level in response to fishing efforts regulation. The results of economic analysis of the enforcement of illegal fishing in traditional fisheries management results are as follows: First, illegal fishing will occur only if enforcement effort is not so high as to remove the incentive to do so, and if the effectiveness of avoidance is not too great, nor its cost too low. Second, avoidance effort will occur at a level jointly proportional to the extent of illegal activity and of enforcement; for given levels of the latter, the desired avoidance effort increase with its effectiveness and decrease with its cost Third, to improve the effectiveness of enforcement, understanding avoidance behavior appears to be crucial to any efforts. Forth, enforcement and fishermen behavior interact depends strongly on characteristics of avoidance, specifically its cost and effectiveness. When avoidance is neither too cheap nor too effective, the interaction is regular. Fifth, in this case, at low levels of enforcement, fishers respond to increases in enforcement by increasing avoidance, but at higher enforcement levels, it becomes uneconomical to continue to do so, and avoidance decreases with enforcement. Sixth, illegal fishing activity decreases steadily with enforcement, so the fishery manager is able, in theory, to reduce illegal fishing toward zero by increasing enforcement. If, however, avoidance is very inexpensive and/or very efficient/ then the optimal level of avoidance will increase indefinitely with increasing enforcement. Finally, less fishery enforcement is required if fishermen have less incentive to overfish, and fishermen have less incentive to avoid fishery enforcement measures.

• The Journal of Fisheries Business Administration
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• v.46 no.2
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• pp.59-74
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• 2015

This study aims to estimate optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the offshore Stow Net and the offshore Gill Net fisheries using the current value Hamiltonian method and the surplus production model. As analyzing processes, firstly, this study uses the Gavaris general linear model to estimate standardized fishing efforts of yellow croaker caught by the above multiple fisheries. Secondly, this study applies the Clarke Yoshimoto Pooley(CY&P) model among the various exponential growth models to estimate intrinsic growth rate(r), environmental carrying capacity(K), and catchability coefficient(q) of yellow croaker which inhabits in offshore area of Korea. Thirdly, the study determines optimal harvesting production, fishing efforts, and stock levels of yellow croaker using the current value Hamiltonian method which is including average landing price of yellow croaker, average unit cost of fishing efforts, and social discount rate based on standard of the Korean Development Institute. Finally, this study tries sensitivity analysis to understand changes in optimal harvesting production, fishing efforts, and stock levels of yellow croaker caused by changes in economic and biological parameters. As results drawn by the current value Hamiltonian model, the optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the multiple fisheries were estimated as 19,173 ton, 101,644 horse power, and 146,144 ton respectively. In addition, as results of sensitivity analysis, firstly, if the social discount rate and the average landing price of yellow croaker continuously increase, the optimal harvesting production of yellow croaker increases at decreasing rate and then finally slightly decreases due to decreases in stock levels of yellow croaker. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts of the multiple fisheries decreases, but the optimal stock level of yellow croaker increases. The optimal harvest starts climbing and then continuously decreases due to increases in the average unit cost. Thirdly, when the intrinsic growth rate of yellow croaker increases, the optimal harvest, fishing efforts, and stock level all continuously increase. In conclusion, this study suggests that the optimal harvesting production and fishing efforts were much less than actual harvesting production(35,279 ton) and estimated standardized fishing efforts(175,512 horse power) in 2013. This result implies that yellow croaker has been overfished due to excessive fishing efforts. Efficient management and conservative policy on stock of yellow croaker need to be urgently implemented.

• Ocean and Polar Research
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• v.40 no.4
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• pp.237-247
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• 2018

This study aims to estimate optimal harvests, fishing efforts, and stock levels of hairtail harvested by the large pair bottom trawl, the large otter trawl, the large purse seine, the offshore long line, and the offshore angling fisheries by using the surplus production models and the current value Hamiltonian method. Processes of this study are as follows. First of all, this study estimates the standardized fishing efforts regarding the harvesting of the hairtail by the above five fishing gears based on the general linear model developed by Gavaris. Secondly, this study estimates environmental carrying capacity (k), intrinsic growth rate (r), and catchability coefficient (q) by applying the Clarke Yoshimoto Pooley (CY&P) model among various surplus production models. Thirdly, this study estimates the optimal harvests, fishing efforts, and stock levels regarding the hairtail by the current value Hamiltonian method, including the average landing price, the average unit cost, and the social discount rate. Finally, this study attempts a sensitivity analysis to figure out changes in optimal harvests, fishing efforts, and stock levels due to changes in the average landing price and the average unit cost. As results induced by the current value Hamiltonian method, the optimal harvests, fishing efforts, and stock levels regarding the hairtail caught by several fishing gears were estimated as 33,133 tons, 901,080 horse power, and 79,877 tons, respectively. In addition, from the results of the sensitivity analysis, first of all, if the average landing price of the hairtail constantly increases, the optimal harvests of it increase at a decreasing rate, and then harvests finally slightly decrease as a result of decreases in stock levels. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts decreases, but optimal stock levels increase. Optimal harvests start climbing and then decrease continuously due to increases in the average unit cost. In summary, this study suggests that the optimal harvests (33,133 tons) were larger than actual harvests (25,133 tons), but the optimal fishing efforts (901,080 horse power) were much less than estimated standardized fishing efforts (1,277,284 horse power), corresponding to the average of the recent three years (2014-2016). This result implies that the hairtail has been inefficiently harvested and recently overfished due to excessive fishing efforts. Efficient management and conservation policies on stock levels need to be urgently implemented. Some appropriate strategies would be to include the hairtail in the Korean TAC species or to extend the closed fishing season for this species.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.163-194
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• 2008

This paper examines the efficacy of the vessel buy - back program implemented by the Korean government between 1994 and 2005. At the descriptive level, it is found that various factors of fishing efforts including power of vessels, fishing days and the number of employees increased during the program. The statistical analysis over the period 1981 to 2005 shows that the amount of weight and power of vessels tend to have a positive impact on the amount of catch with the number of vessels controlled. In particular, 1% increase in weight and power leads to $0.5%{\sim}1.4%$ and $1.0%{\sim}2.0%$ increase in catch, respectively. Therefore, the results suggest that the vessel buy - back program in Korea had contributed to reducing the catch but only as far as it reduced the weight and power of the vessels. As is consistent with the previous literature, it is indicated that the efficacy of vessel buy - back program may be limited by the fishermen's effots to increase the fishing efforts in terms of power of vessels, fishing days or number of employees.

• The Journal of Fisheries Business Administration
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• v.30 no.2
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• pp.39-54
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• 1999

This paper focused on meaning, problems and prospect of structural reform of coastal and offshore fisheries in Korea. Structural reform can be defined as effective combination of production factors in order to enhance fisheries productivity and it can be realized mainly through fleet reduction, modernization of fishing vessels and fishing gear etc. However, the structural reform alone will not be sufficient to advance Koreanl fisheries facing with severe challenges from both inside and outside. Domestically, worsening status of fisheries resources, decreasing number of fishermen, worsening financial status of fisheries businesses and severe competition cause structural problem in fisheries sector and internationally the pressure from WTO and OECD to reduce tariff and subsides in fisheries poses severe challenges. The structural reform should be carried out in relation with the general adjustment programs across coastal and offshore fisheries such as M&A among fisheries businesses, adjustment of number of fishing permits and fishing areas. And the policy to enhance the fishing productivity is needed for recovery of fisheries resources and for the reduction of fishing efforts, that is, the approach which combines economic and resources concerns is needed. For the effective implementation of the reform, effect analysis of the reform program is needed and at the same time, eradication of illegal fishing, reduction of fishing fleet and reduction of fishing cost should be realized. However, the most important thing is the will and efforts of the government for successful reform. If the government does not exert sufficient efforts for the structural reform, Korea could be degraded into a backward country in fisheries.

• Ocean and Polar Research
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• v.31 no.2
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• pp.157-165
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• 2009

The study examined overuse of the fishery resource. Influence of fishing activity was estimated by application of Schaefer model's. Fishing efforts that produced the maximum sustainable yield were determined in the model, allowing the effect of overfishing to be assessed. In the model, a wide variety of fish species as well as crustaceans and shellfish were susceptible to overfishing, while mollusks were not. Overfishing by modern techniques exacted a greater toll than more traditional methods. The results of the modeling study suggest that the 'Buy bag' input-control system of fisheries resource management warrants consideration, as does modernization, expansion and strengthening of self-control management of the fishery resource. Finally, more effective efforts in dissemination of policy information and education concerning the fishery resource are needed.

• The Journal of Fisheries Business Administration
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• v.53 no.3
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• pp.43-64
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• 2022

Efforts to prevent IUU fishing began in 1996 as the IUU Antarctic Marine Living Resources Conservation Committee reported the multilateral efforts of the international community and related international organizations to prevent IUU fishing. Korea has recently been pointed out by the international community as to many problems regarding its will to eradicate IUU fishing. It is true that Korea has ever been designated as an 'IUU participating country' or a 'non-cooperative third country' by the international community and that there have been considerable difficulties in exporting seafood and using ports along with the deterioration of the national image. In 2020, with the efforts of related organizations and fisheries companies, Korea is now free from being known as a that Korea has recovered some degrees of trust from the international community through strengthening legal sanctions against IUU fishing and thorough implementation of follow-up measures is now free from non-cooperating country it cannot be said that the basic problems have been completely resolved just because it has emerged as a disgraceful country, and the current state of IUU fishing of Korea leaves a room for designation as a 'non-cooperative third country' again at any time in the future. Accordingly, there is an urgent need to examine the problems of the IUU fishing-related legal system in Korea and to come up with an improvement plan. Therefore, this paper reviews international norms for IUU fishing regulation (PSMA etc.) and domestic laws with the Distant Water Fisheries Development Act and Propose the improvement methods for related legal systems in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.394-402
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• 2016

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 ($E_{MEY}$) as the most economically efficient one for the Eastern Sea Danish seine fisheries. The results showed that the optimal economic fishing effort ($E_{MEY}$) 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 $E_{MEY}$ could lead to the reduction of fishing costs, thereby resulting in the increased fishing profits.

• The Journal of Fisheries Business Administration
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• v.33 no.2
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• pp.31-48
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• 2002

This paper is aimed to analyze how to evaluate the choice of optimal management measures and level of control in fisheries management under the costly and imperfect management system by comparing with costless and perfect management system that is commonly assumed in the analysis of fisheries regulations. Fishermen would set the level of fishing efforts at the point where the marginal fishing profit for fishing effort is equal to the marginal level of fine under costly and imperfect management system. Therefore, under the case where the marginal fishing profit is higher than the marginal level of fine, the level of fishing efforts would be made at the point which is higher than the level of fishing efforts made under costless and perfect management system and is not a point where the economic profit is maximized in regulated fisheries. From this conclusion, the fishermens avoidance activities against regulations as well as the level of control in fisheries management substantially have an influence on the choice of fisheries management instruments. According to the analysis of optimal fisheries management policy, the economic profits in regulated fisheries are determined by the level of fisheries enforcement costs and total fishing profits, in which as enforcement costs increase the economic profits decrease. In addition, the economic profits vary in response to the level of control in avoidance activities. That is, as avoidance costs decrease, the economic profits increase. The determination of optimal level of control in fisheries management should be made at the point where the marginal regulation costs are equal to the marginal profits from regulated fisheries, in which marginal regulation costs are different according to the type of management measures. And the level of profits changes in response to different levels of avoidance activities. The management measure that can maximize the difference between the marginal regulation costs and marginal profits from regulated fisheries should be chosen as an optimal fisheries management instrument.

• The Journal of Fisheries Business Administration
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• v.25 no.1
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• pp.37-59
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• 1994

Many studies to cope with the present problems of Korean coastal and offshore fisheries has been performed, but these were done partly in necessities and general studies for Korean inshore and offshore fisheries are in early stage. Most of these studies adopted analytical way of approach for each fishery individually and they could not reflect the effect of correlated interaction among fisheries on the several common species/stocks, and thus optimal effort allocation was impossible. To consider general fisheries and optimal effort allocation among competing mixed species, a linear programming (LP) approach is applied in this study and introduced into 16 important inshore and offshore fisheries with 13 constraining species which were chosen by annual yield order. This study is not based on the biological interaction among species (i.e., prey - predator system) but the technological interaction between species and fishing efforts. For the application of LP model in these fisheries, the standardization of fishing efforts through different fishing gears could not be successful and a new way of effort standardization through CPUE for vessel tonnage was originated. Total standardized fishing effort on a particular species i, Ei, is computed as the linear summation of standardized fishing effort generated by each fishery j. That is, (equation omitted) where $f_{j}$ is the total vessel tonnage of fishery j and aij is the coefficients contributing to the standardized fishing effort per ton for species i taken in fishery j. The total fishing effort level on species i due to both directed fishing and by - catch can thus be accounted in the aij's. Optimal effort allocation among the j fisheries may be considered a minimizing problem (minimize $\Sigma$ $f_{j}$), subject to the constraints that standardized fishing effort levels on particular species are maintained at, above, and below certain predefined levels. Fishing effort goals for individual species can be based on various biological and/or economic criteria, i.e., fishing effort level generating maximum sustainable yield and/or maximum economic yield. But in this study the $F_{0.1}$ criteria which was accepted as an approximate level for $F_{mey}$ by Outland and Boerema's (1973) study. The findings of this study are, (1) LP model can be applied to the Korean inshore and offshore fisheries giobally. (2) Through a new way of combining multiple different fisheries' efforts for a particular species together generating standardized fishing effort, Schaefer curve could be applied to the complex system successfully. (3) The results of this study for total reduction scale were mostly the same as those of prior studies, but different much from the individual scales of reduction. This study showed the necessities for exploitation of more concrete parameters to put into consideration of profitability of fisheries and social factors, and this model can be modified according to the actual constraints. Also, considering the age structure of stocks, this model can be developed into better one for better fisheries management.ent.