보문 : 담수산 어류 꺽지 (Coreoperca herzi)의 자원 평가 및 관리 방안 연구: 섬진강 중,상류 수계에서 꺽지의 자원량 및 잠재생산량 추정(2)

장성현 ( Sung Hyun Jang ),류희성 ( Hui Seong Ryu ),이정호 ( Jung Ho Lee ) 한국하천호수학회(구 한국육수학회) 2011 생태와 환경 Vol.44 No.2

The study sought to determine the efficient management of Korean aucha perch by estimating the potential yield (PY), which means the maximum sustainable yield (MSY) based on the optimal stock, in the mid-upper region of the Seomjin River watershed from August 2008 to April 2009. The stock assessment was conducted by the swept area method and PY was estimated by a modified fisheries management system based on the allowable biological catch. Also, the yield-per-recruit analysis (Beverton and Holt, 1957) was used to review the efficient management of resource, Coreoperca herzi. The age at first capture (t(c)) was 1.464 age and converted body length was 7.8 cm. Concerning current fishing intensities, the instantaneous coefficient of fishing mortality (F) was estimated to be 0.061 year-1; yield-per-recruit analysis estimated the current yield per recruit as 4.124 g with F and t(c). The fishing mortality of Allowable Biological Catch (F(ABC)) based on the current t(c) and F was estimated to be 0.401 year-1, therefore, the optimum. fishing intensities could be achieved at the higher fishing intensity for Coreoperca herzi. The calculated annual stock of Coreoperca herzi was 3,048 kg, the potential yield was estimated to be 861 kg with t(c) and F(ABC) at the fixed current level. Using yield-per-recruit analysis, if F and t(c) were set at 0.643 year-1 and 3 age, respectively, the yield per recruit would be predicted to increase 3.4-fold, from 4.12 g to 13.84 g.

한국 연근해 황아귀 Lophius litulon (Jordan)의 자원평가 및 관리방안 연구

박영철,이재봉,최석관,안두해 한국수산자원학회 2003 한국수산자원학회지 Vol.6 No.-

본 연구에서는 1985년부터 2001년까지 17년간의 황아귀 어획량 및 노력량 자료와 어획물 체장조사 자료를 이용하여 한국 연근해 황아귀 자원에 대한 자원생물학적특정치를 추정하였다. 어획물곡선을 이용하여 추전된 한국 연근해 황아귀의 순간전 사망계수 (Z)는 0.91/년이며, 어구가입연령 (t_(c))은 1.3세였다. 또한, 자연사망계수 (M)는 0.27/년으로, 순간어획사망계수 (F)는 0.64/년으로, 어장가입연렁(t_(r))은 0.3세로 추정되었다. 황아귀 자원을 가입당생산량 모델에 적용시킨 결과, 가능한 최대 가입당생산량이 948g 임에 비하여 현재의 t_(c) = 1.3세, F = 0.64/년에서의 가입당생산량은 559g 정도로 나타났다. 여기서 t_(c)를 현재 상태로 고정시킨 후, 가입당생산량을 높이는 방안을 생각해 보면, 현재의 F 값 0.64/년에서 증가할수록 가입당생산량은 감소하는 경향을 보이고 있지만, 현재의 어획강도 (F)를 고정시키는 경우에는 t_(c)를 현재의 1.3세에서 4세 부근으로 조정하면 최대의 가입당생산량(948g)을 얻을 수있고, 이 t_(c)값은 역시 F_(0.1)방법에서 추정된 적정 어획체장음 연력으로 환산한 결과와 거의 일치하였다. 또한, 가입당생산량 및 가입당산란자원량 모델을 이용하여 생물학적 관리기준점이 되는 F_(0.1)과 F_(35%) 및 F_(40%)을 각각 0.14/년, 0.26/년, 0.22/년으로 설정하였다. 지난 17년간 어획자료를 사용하여 잉여생산모델에 의해 추정된 MSY는 Schaefer와 Fox 모델에 의하여 각각 7.740톤과 7.720톤으로 유사한 결과를 나타냈다. 또한, CPUE/CPUE_(M8Y) 비는 1보다 큰 값을 보여 황아귀의 자원상태는 한국 TAC 산정을 위한 ABC 추정시스템의 4a 단계에 해당되었다. 따라서, MSY 및 자원상태를 고려하여 한국 연근해 황아귀 자원의 2002년도 관리시점의 생물학적허용어획량은 7,730톤이 적정한 것으로 판단되었다. The purpose of this study is to estimate population ecological parameters, including instantaneous coefficients of natural and fishing mortalities, and age at first capture, as well as to carry out stock assessment of yellow goosefish Lophius litulon (Jordan) in Korean wafers. Using the catch curve, the instantaneous coefficient of total mortality (Z) of yellow goosefish was estimated at 0.91/year and the age at first capture. 1.3 years. The instantaneous coefficients of natural and fishing mortalities (M and F) were estimated to be 0.27/year and 0.64/year, respectively. A yield-per-recruit (YPR) analysis showed that the current yield per recruit of about 559 g with F of 0.64/year at t_(c) of 1.3 years. was lower than the possible maximum yield per recruit of 948 g. With to fixed at the current level, the yield per recruit tended to decrease as the current F (0.64/year) value increased. Thus, it is suggested that the maximum yield per recruit can be attained with a fixed F value at the current level by increasing t_(c) from 1.3 rears to 4.0 years. Based on YPR and spawning biomass per recruit (SPR) models, the biolegical reference points, such as F_(0.1), F_(35%), F_(40%), were suggested as 0.14, 0.26, 0.22 per year at current age 1 of recruitment. Employing surplus production model (SPM) with catch per unit effort of the Korean large stow net fishery during the periods of 1985-2001, the estimated MBYs were similar between the Schaefer and Fox models, ranged from 7,74D to 7,720 mt. Finally, we suggested that acceptable biological catch (ABC) of yellow goosefish in 2002 should be 7,730 mt, based on the MSY and the current status of the stock in Korean waters.

최대지속생산량(MSY : Maximum Sustainable Yield) 모형을 이용한 근해어업의 적정 어선세력 추정에 관한 연구

김대현 한국도서(섬)학회 2019 韓國島嶼硏究 Vol.31 No.1

Over-fishing, defined as exceeding the biological fishing capacity, has caused a number of problems, including a decline of fishing stocks and a significant decline in the profitability of fishermen. In order to solve these problems, an efficient and comprehensive plan is needed, and the Korean government has implemented a Fishing Capacity Reduction Program since 1994. In particular, in 2002, the government set up comprehensive measures to restructure the coastal and offshore fisheries in order to promote more comprehensive and systematic fisheries reduction projects. The government is continuing efforts to improve its competitiveness in the fisheries sector and to restore the fishing resources of the coastal and offshore fisheries to an appropriate, sustainable level. However, in the meantime, the license buy-back program has been promoted as coastal fishing vessels, and high-catching offshore fishing vessels (such as trawlers) have limited participation in the fishing capacity reduction program. In 2018, the government has set a budget of KRW 4,840 million annually for the offshore fishing capacity reduction program until 2021. Therefore, this study aims to analyze the proper fishing capacity of offshore fisheries and to present criteria to judge whether or not it is in the state of over-fishing by analyzing the proper fishing capacity of offshore fisheries. The results of this study will also provide a criterion to determine whether it is appropriate to continue the catch reduction program. The analytical method utilizes the Schaefer and Fox models based on the Maximum Sustainable Yield (MSY) theory, which has long been used as a management objective for fisheries around the world. 어업자원의 자연성장율을 초과하는 과도한 생물학적 어획능력으로 정의된 과잉어획은 어업자원의 감소와 어업인들의 수익성 악화를 비롯한 많은 문제들을 야기했다. 이러한 문제를 해결하기 위해서는 효율적이고 종합적인 계획이 필요하며, 한국 정부는 1994년부터 지속적으로 연근해어선감축 프로그램을 시행하고 있다. 특히 2002년에는 정부가 보다 포괄적이고 체계적인 어선감축사업을 추진하기 위해 연근해 어업의 구조조정을 위한 종합 대책을 마련하였으며, 현재에도 정부는 어업부문의 경쟁력을 높이고 연근해어업의 어업자원을 적절한 수준으로 회복시키기 위한 노력을 계속하고 있다. 2005년 이후 최근까지 대규모 연근해 어선감척사업의 추진에도 불구하고 2018년 현재 정부는 2021년까지 근해어업 어획능력 감축을 위한 예산을 매년 4,840백만 원으로 책정하고 있다. 그러나 연근해 어선감척사업은 정부의 대규모 재정투입이 요구되고, 필요 이상의 감척은 오히려 수산업분야에서의 경쟁력을 약화시키는 요인이 될 수 있기 때문에 적절한 수준에서 유지하는 것이 바람직하다. 현재 어선감척사업의 지속성 여부에 대한 합리적인 판단이 필요한 시점으로 판단되며, 따라서 본 연구에서는 근해어업의 사례분석을 통하여 현재 근해어업의 어획능력이 과도한 상태인지 또는 최적 어획능력의 범위 내에 있는지 분석하여 감척사업의 지속성 여부를 판단하는 기준을 제시하고자 한다. 본 연구에서의 분석방법은 오랫동안 전 세계 수산업분야의 관리 목표로 활용 되어온 최대지속생산량(MSY) 이론을 기반으로 한 Schaefer 모형과 Fox 모형에 기초한다. 특히 각 모형의 설명력을 높이기 위하여 이론적 탐색을 통하여 최적의 변수 및 모형을 제시였으며, 본 연구결과에서는 근해어업에서 어획노력의 추가감축 여부 및 초과 어획노력량에 대한 계량적 수치를 제시하였다.

카리브호수 카펜타 자원량 추정을 위한 최대엔트피모델과 분석적 모델의 비교분석

이타이 텐다우펜유 ( Itai Hilary Tendaupenyu ),표희동 ( Hee-Dong Pyo ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2017 자원·환경경제연구 Vol.26 No.4

카리브호수의 카펜타 자원량을 추정하기 위해 최대엔트로피(ME)모델과 분석적 모델이 적용된다. ME모델을 이용하여 25,372톤의 최대지속가능 어획량(MSY)과 MSY의 어획노력량인 109,731의 어획일수(fishing nights)를 추정하였는데, 이는 현재 어획노력량 수준이 과잉투자됨으로써 1988년 이후 2009년 현재까지 자원량을 감소시키는 요인인 것을 나타낸다. 분석적 모델은 매년의 생물학적 허용 어획량(ABC)과 연간 1.21의 어획사망계수(일반적 어획사망계수인 0.927 보다 큰)를 추정한다. 이 두 모델은 1982년 기준년도의 자원량 추정에 적용할 수 있는 유사한 자원량을 추정한다. ME모델에 의하면 1988년의 최대 자원량(156,047톤)에 대해 1/3수준이하 까지 점점 하락하는 결과를 추정하였는데, 이는 최근의 어획량이 MSY 수준 이하이지만 ABC수준보다 높게 나타나 남획된 것을 암시한다. 다시 말해서, 분석적 모델은 ME모델에서의 MSY보다 더 보수적인 ABC를 제공함으로써, 보수적인 어업관리정책(총허용어획량제도, 어획노력감소정책 등)을 적극적으로 고려해야함을 내포하고 있다. A Maximum Entropy (ME) Model and an Analytical Model are analyzed in assessing Kapenta stock in Lake Kariba. The ME model estimates a Maximum Sustainable Yield (MSY) of 25,372 tons and a corresponding effort of 109,731 fishing nights suggesting overcapacity in the lake at current effort level. The model estimates a declining stock from 1988 to 2009. The Analytical Model estimates an Acceptable Biological Catch (ABC) annually and a corresponding fishing mortality (F) of 1.210/year which is higher than the prevailing fishing mortality of 0.927/year. The ME and Analytical Models estimate a similar biomass in the reference year 1982 confirming that both models are applicable to the stock. The ME model estimates annual biomass which has been gradually declining until less than one third of maximum biomass (156,047 tons) in 1988. It implies that the stock has been overexploited due to yieldings over the level of ABC compared to variations in annual catch, even if the recent prevailing catch levels were not up to the level of MSY. In comparison, the Analytical Model provides a more conservative value of ABC compared to the MSY value estimated by the ME model. Conservative management policies should be taken to reduce the aggregate amount of annual catch employing the total allowable catch system and effort reduction program.

잉여생산량을 추정하는 모델과 파라미터 추정방법의 비교

권유정 ( You Jung Kwon ),장창익 ( Chang Ik Zhang ),표희동 ( Hee Dong Pyo ),서영일 ( Young Il Seo ) 한국어업기술학회 2013 수산해양기술연구 Vol.49 No.1

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 44,844 mt by ME model, and fishing effort at MSY (fMSY) ranged from 262,188 hauls by Schnute model to 355,200 hauls 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 (R2) 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 25,373 mt by ME model, and fMSY, from 94,580 hauls by ASPIC model to 225,490 hauls by Schnute model. In this case, both the lowest root mean square error (RMSE) and the highest coefficient of determination (R2) 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 (BMSY), carrying capacity of the population (), catchability coefficient () and the intrinsic rate of population growth ().

Optimal economic fishing efforts in Korean common octopus <i>Octopus minor</i> trap fishery

KIM, Do Hoon,AN, Heui Chun,LEE, Kyoung Hoon,HWANG, Jin -wook Blackwell Publishing Asia 2008 Fisheries Science Vol.74 No.6

<P>ABSTRACT</P><P>The Korean Government is in the process of establishing a plan for managing fishing effort by setting up the maximum fishing gear usage per fishery type for the recovery of fishery resources. This will aid settlement of disputes between fishery sectors over fishing gears, and the stability of fishing business conditions. Especially in the setting up of the maximum fishing gear usage, economic standards as well as biological standards are being considered as significant factors to promote the sustainable and economically viable development of fisheries. This study is, thus, to analyze the optimal economic fishing gear usage (E<SUB>MEY</SUB>) as the most economically efficient usage for the common octopus trap fishery, one of the most controversial sectors in establishing maximum fishing gear usage. Data from logbooks per trip were used for estimation of E<SUB>MEY</SUB> per trip because it was considered there were limitations of data available for analyses. As a finding drawn from the analyses, the E<SUB>MEY</SUB> of common octopus trap vessels per trip has to be decreased by approximately 13%. That is, reducing the trip trap usage up to the level of E<SUB>MEY</SUB> can lead to the reduction of trip fishing costs, thereby resulting in increased trip profits.</P>

대문어 연안복합어업의 경제적 적정어획노력량 추정 -강원도 연안복합어업을 대상으로-

최지훈,권대현,이재봉,양재형,김도훈 한국수산해양기술학회(구 한국어업기술학회) 2018 수산해양기술연구 Vol.54 No.4

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 EMEY. 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 EMEY. Although current fishing effort is similar to the EMSY, current catching is 16% higher than MSY and 22% higher than MEY.

기름가자미 어업관리를 위한 생물경제학적 분석

최지훈 ( Ji-hoon Choi ),최완현 ( Wan-hyun Choi ),김도훈 ( Do-hoon Kim ) 한국어업기술학회 2016 수산해양기술연구 Vol.52 No.4

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.

An Ecosystem-Based Assessment of Hairtail (Trichiurus lepturus) Harvested by Multi-Gears and Management Implications in Korean Waters

강희중,장창익,이은지,서영일 한국해양과학기술원 2015 Ocean science journal Vol.50 No.2

Hairtail (Trichiurus lepturus) has been traditionally harvested by multi-gear types in the Yellow Sea and the East China Sea, except for the East Sea (Sea of Japan) in Korean waters. Six different fishery types such as offshore stownet fishery, offshore longline fishery, large pair-trawl fishery, large purse seine fishery, large otter trawl fishery and offshore angling fishery target to harvest the hairtail stock accounting for about 90% of the total annual catch. We attempted to develop an ecosystem-based fisheries assessment approach, which determines the optimal allocation of catch quotas and fishing efforts for major fisheries. We conducted standardization of fishing effort for six types of hairtail fisheries using a general linear model (GLM), and then estimated maximum sustainable yield (MSY) and maximum economic yield (MEY). Estimated MSY and MEY for the hairtail stock were estimated as 100,151 mt and 97,485 mt, respectively. In addition, we carried out an ecosystem-based risk analysis to obtain species risk index (SRI), which was applied to adjusting the optimal proportion of fishing effort for six hairtail fisheries as a penalty or an incentive. As a result, fishing effort ratios were adjusted by SRI for the six fisheries types. Also, the total allowable catch (TAC) was estimated as 97,485 mt and the maximum net profit at TAC by the hairtail fisheries was estimated as 778 billion won (USD 765 million).

기름가자미 어업관리방안 평가를 위한 생물경제학적 분석 - 동해구외끌이중형저인망어업을 대상으로 -

최지훈,강희중,임정현,김도훈 한국수산해양기술학회 2020 수산해양기술연구 Vol.56 No.4

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. 본 연구에서는 기름가자미 자원평가를 위해 Bayesian State-space 모델 활용하여 기름가자미의 자원상태를 평가 하였다. 또한 어업관리방안들에 대한 효과분석을 통해 효과적은 어업관리방안의 제시 및 선택을 하고자 하였다. Bayesian State-space 모델 사용하여 분석한 결과, 기름가자미의 주요생물계수 값은 MSY는 1,985톤, K는 23,930톤 q는 0.000007765그리고 r은 0.31로 분석되었다. 효과적인 어업관리방안의 선택 및 제시를 위해 생물경제모델을 활용하여 분석하였다. TAC 정책의 생물학적 효과분석 결과, 현재 수준과 같이 1,761톤으로 설정되어 지속된다면 기름가자미 자원량이 20년 후에는 14,637톤으로 유지하는 추세로 평가되었다. 하지만 기름가자미 TAC설정이 1,600톤으로 설정할 경우 향후 16,252톤으로 자원량은 증가되는 것으로 추정되었다. 어획노력량 저감 정책의 생물학적 효과분석 결과, 현재 어획노력량(현재hp) 수준으로 설정되어 지속될 경우 기름가자미 자원량이 13,776톤으로 유지하는 추세로 평가되었다. 하지만 어획노력량을 20% 감소시킬 경우 향후 17,091톤으로 증가하는 것으로 분석되었다. TAC 정책의 경제학적 효과분석 결과, TAC 물량 2,500톤 설정 시 20년 후인 2038년 NPV는 1,486,410천원으로 가장 낮은 수준으로 분석되었다. 하지만 TAC를 2,000톤으로 설정시, NPV는 2,206,522천원으로 가장 높은 것으로 추정되었다. 어획노력량 저감 정책의 경제학적 효과분석 결과, 현재 어획노력량 수준으로 유지되면 20년 후인 2038년 NPV는 2,235,592천원으로 수준으로 분석되었다. 하지만 어획노력량을 10% 증가시킬 경우 NPV는 2,257,575천원으로 가장 높은 수준으로 분석되지만, 생물학적 측면에서는 자원량이 감소하는 것으로 분석되었다.