• Ocean and Polar Research
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• 제31권2호
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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.

• Ocean and Polar Research
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• 제39권3호
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• pp.195-203
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• 2017

The purpose of this paper is to estimate the optimal $CO_2$ emission in the maximum economic yield (MEY), maximum sustainable yield (MSY), and open access (OA) using a bioeconomic model. The results are as follows; in the case of $E_{MEY}$, $E_{MSY}$, and $E_{OA}$ levels, $CO_2$ emissions are estimated at $150,704,746CO_2/kg$, $352,211,193CO_2/kg$, and $301,409,492CO_2/kg$ respectively. We show that the $E_{MEY}$ is more efficient than the other levels. That is, the level of $E_{MEY}$ signifies the optimal economic fishing usage as the most economically efficient usage for large purse seine fishery catching mackerel species. The emission of $CO_2$ in $E_{MEY}$ is the lowest level. Also, the impacts of climate changes such as ocean temperature increase, ocean acidification, and the combined impact thereof show that the biomass of mackerel decreases.

• 수산해양기술연구
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• 제49권1호
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• pp.18-28
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• 2013

It was compared the estimated parameters by the surplus production from three different models, i.e., three types (Schaefer, Gulland, and Schnute) of the traditional surplus production models, a stock production model incorporating covariates (ASPIC) model and a maximum entropy (ME) model. We also evaluated the performance of models in the estimation of their parameters. The maximum sustainable yield (MSY) of small yellow croaker (Pseudosciaena polyactis) in Korean waters ranged from 35,061 metric tons (mt) by Gulland model to 44,844mt by ME model, and fishing effort at MSY ($f_{MSY}$) ranged from 262,188hauls by Schnute model to 355,200hauls by ME model. The lowest root mean square error (RMSE) for small yellow croaker was obtained from the Gulland surplus production model, while the highest RMSE was from Schnute model. However, the highest coefficient of determination ($R^2$) was from the ME model, but the ASPIC model yielded the lowest coefficient. On the other hand, the MSY of Kapenta (Limnothrissa miodon) ranged from 16,880 mt by ASPIC model to 25,373mt by ME model, and $f_{MSY}$, from 94,580hauls by ASPIC model to 225,490hauls by Schnute model. In this case, both the lowest root mean square error (RMSE) and the highest coefficient of determination ($R^2$) were obtained from the ME model, which showed relatively better fits of data to the model, indicating that the ME model is statistically more stable and robust than other models. Moreover, the ME model could provide additional ecologically useful parameters such as, biomass at MSY ($B_{MSY}$), carrying capacity of the population (K), catchability coefficient (q) and the intrinsic rate of population growth (r).

• Ocean and Polar Research
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• 제41권3호
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• pp.183-191
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• 2019

This study sought to find which model is most appropriate for estimating potential yield in the East Sea, Republic of Korea. For comparison purposes, the Process-error model, ASPIC model, Maximum entropy model, Observation-error model, and Bayesian state-space model were applied using data from catch amounts and total efforts of the whole catchable fishes in the East Sea. Results showed that the Bayesian state-space model was estimated to be the most reliable among the models. Potential yield of catchable species was estimated to be 227,858 tons per year. In addition, it was analyzed that the amount of fishery resources in 2016 was about 63% of the biomass that enables a fish stock to deliver the maximum sustainable yield.

• 자원ㆍ환경경제연구
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• 제31권4호
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• pp.451-480
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• 2022

본 연구는 한국에서 상업적 중요성을 가지며 국민 선호도가 높은 살오징어의 자원상태를 파악해 보고자 하였다. 본 연구에서는 기존 살오징어 자원평가 연구와의 차별성으로 두 가지를 고려하였다. 첫째, 한국에서 살오징어를 어획하는 업종들의 어획 자료를 자원평가 분석에 최대한 활용하였다. 둘째, 살오징어를 공동 어획하는 인접국인 중국과 일본의 어획 자료를 모두 포함하여 자원평가를 실시하였다. 구체적인 분석에 있어서는 어획량 기반 자원평가 모델인 Monte Carlo 방법을 활용한 CMSY(catch-maximum sustainable yield) 모델과 Schaefer 함수를 기반으로 한 Bayesian state-space(BSS) 모델을 이용하여 활용 가능한 자료의 종류와 범위에 따라 '한국' 그리고 '한·중·일'로 해역 범위를 구분하여 분석을 실시하였다. 분석 결과, 살오징어 자원량은 감소하는 추세를 보이고 있으며, 현재 최대지속어획량을 달성할 수 있는 자원량 수준보다 낮은 것으로 추정되었다. 살오징어 자원을 지속적으로 이용하기 위해서는 개별 국가들의 적극적인 자원관리 노력이 필요하며, 특히 한·중·일 공동 자원조사 및 평가 그리고 관리 방안 마련이 필요하다.

• 한국수산과학회지
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• 제45권5호
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• pp.493-498
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• 2012

We derived biological reference points for Pacific cod Gadus macrocephalus in southeastern Korean waters by applying a yield-per-recruit analysis based on a daily simulation that adopted size-dependent fecundity, growth, and natural mortality functions. This showed that the yield per recruit of Pacific cod can be maximized at an instantaneous rate of fishing mortality (F)=0.37 $yr^{-1}$ under the current regulations, where the minimum catch size ($L_c$)=30 cm in total length (TL). The maximum economic yield was estimated to be attained at $L_c$=35-45 cm TL, if F>1 $yr^{-1}$ but at $L_c$=35-40 cm TL, if F<1 $yr^{-1}$. Despite great uncertainty in the stock assessment, to develop fisheries management plans for the sustainable exploitation of Pacific cod in southeastern Korean waters, it is necessary to estimate F using capture-recapture or other expedient methods.

• Ocean and Polar Research
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• 제39권3호
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• pp.221-232
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• 2017

The purpose of this study is to estimate the extent of fisheries resource rebuilding and other economic effects on coastal gill-net fishery as a result of the Korean vessel buy-back program using with-without analysis based on methods estimating sustainable yields for all species caught by coastal gill-net fishery. Based on the results of with-without analysis, maximum sustainable yields (MSY) of all species caught by coastal gill-net fishery have been increased by the Korean vessel buy-back program. In addition, profits per vessel of maximum economic yield (MEY) of the species have been improved by the program. Further, yields and a producer surplus per vessel under an equilibrium of open access (OA) have increased because of the program. In detail, first of all, at the MSY level, the vessel buy-back program has led to about 21% fisheries resource recovery, and at the MEY level, it has led to about a 19% resource recovery. Secondly, at the MEY level and the OA level, the producer surplus per vessel has been increased by about 24% and 22% respectively by the vessel buy-back program.

• 한국수산과학회지
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• 제22권4호
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• pp.196-200
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• 1989

최근 몇 년간 제주도의 소라 생산량이 급감하고 있는바, 그 원인 규명을 위한 목적으로 노력당 어획고의 변동 및 최대지속생산량을 추정하기 위하여, 1968년에서 1986년까지의 제주도 소라어획통계자료와 1984년에서 1986년까지의 동귀리(복제주군 애월읍) 어촌계의 작업일지를 분석하였으며, 그 결과는 다음과 같다. 동귀리 어촌계의 경우, 소라 어획량은 제주도 총 소라 어획량의 $1\%$에 지나지 않으며, 실제 조업한 해녀수는 등록된 해녀수의 $53.4\%$인 63명이었다. 그리고 어획노력량으로서는 작업일수 보다 해녀수를 선정함이 양호하다. 제주도의 연간 최대지속생산량은 $2,500\~2,800$톤으로 추정되었으며 1982년에서 '85년까지의 어획량은 $3,100\~3,650$톤으로 과잉의 어획시기였고, 그로 인해 1986년은 매우 감소한 1,400톤이었다. 이전 상태로 어업을 지속할 경우 매우 심각한 상태에 도달할 것으로 예상된다.

• 자원ㆍ환경경제연구
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• 제25권4호
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• pp.517-543
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• 2016

본 연구의 목적은 우리나라 기선권현망 멸치어업의 유류비 변동에 대한 영향을 분석하는 데 있다. 연구의 분석 방법으로, 우선 최대지속적어획량(MSY)을 추정하기 위하여 지수잉여 생산모형을 이용한다. 다음으로, 자유어업하에서의 유류비 변동에 대한 기선권현망어업의 생산자 잉여를 추정하기 위하여 생물경제모형을 적용한다. 본 연구의 분석 결과, 면세유 미지급으로 인한 유류비 상승은 기선권현망어업의 멸치 공급에 대한 생산자 잉여에 부정적 영향을 초래하는 것으로 나타났다. 그러나 기선권현망 멸치어업의 유류비 상승이 경영 상태가 좋지 못한 어업인의 퇴출을 유도함으로써 상기 어업의 어획노력량을 최대지속적어획량 수준의 어획노력량($F_{MSY}$) 이하로 감소시켜 멸치 자원의 회복과 더불어 잔존 어업자의 생산자 잉여를 개선시키는 효과를 유인하는 것으로 나타났다.

• 한국수산과학회지
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• 제41권2호
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• pp.107-112
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• 2008

To evaluate uncertainty and risk in biological reference points, we applied a bootstrapping method and a Bayesian procedure to estimate the related confidence intervals. Here we provide an example of the maximum sustainable yield (MSY) of turban shell, Batillus cornutus, estimated by the Schaefer and Fox models. Fitting the time series of catch and effort from 1968 to 2006 showed that the Fox model performs better than the Schaefer model. The estimated MSY and its bootstrap percentile confidence interval (CI) at ${\alpha}=0.05$ were 1,680 (1,420-1,950) tons for the Fox model and 2,170 (1,860-2,500) tons for the Schaefer model. The CIs estimated by the Bayesian approach gave similar ranges: 1,710 (1,450-2,000) tons for the Fox model and 2,230 (1,760-2,930) tons for the Schaefer model. Because uncertainty in effort and catch data is believed to be greater for earlier years, we evaluated the influence of sequentially excluding old data points by varying the first year of the time series from 1968 to 1992 to run 'backward' bootstrap resampling. The results showed that the means and upper 2.5% confidence limit (CL) of MSY varied greatly depending on the first year chosen whereas the lower 2.5% CL was robust against the arbitrary selection of data, especially for the Schaefer model. We demonstrated that the bootstrap and Bayesian approach could be useful in precautionary fisheries management, and we advise that the lower 2.5% CL derived by the Fox model is robust and a better biological reference point for the turban shells of Jeju Island.