• Title/Summary/Keyword: optimal sustainable yield

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Reviewing the Assessment of Optimal Yield of Groundwater in Korea

  • Soo-Hyoung Lee;Jae Min Lee;Se-Yeong Hamm
    • Journal of Environmental Science International
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    • v.33 no.7
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    • pp.511-522
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    • 2024
  • The optimal yield is defined as the amount of groundwater that maintains a dynamic equilibrium state of the groundwater system over a long period. We examined the current problems, improvements, and methods for estimating the optimal groundwater yield in Korea, considering sustainable groundwater development. The optimal yield for individual wells and the sustainable yield for the entire groundwater basin were reviewed. Generally, the optimal yield for individual wells can be determined using long-term pumping and step drawdown tests. The optimal yield can be determined by groundwater quantity and quality, economic, and water use rights factors. The optimal yield of individual wells in the groundwater basin must be determined within the total sustainable amount of the entire groundwater basin, such that the optimal yield of a new well must be less than the remaining total sustainable amount, exempting the total optimal yield of the existing wells. Therefore, the optimal yield may be determined based on the estimated optimal yield at least twice per year. In addition, if groundwater level and pumping quantity data for at least one year are available, it may be effective to use the Hill, Harding, and zero groundwater-level change methods to re-estimate the optimal yield.

Bioeconomic Management Policy for Fisheries Resources (생물경제학적 어업자원 관리정책에 관한 연구)

  • PYO, Hee-Dong;KWON, Suk-jae
    • Journal of Fisheries and Marine Sciences Education
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    • v.16 no.1
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    • pp.84-98
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    • 2004
  • Due to a publicly owned resources, the overexploitation of the fisheries resources can result in externalities in the form of reduced future levels of yield. These problems can be theoretically improved through effective management of the fishery. The paper illustrates maximum sustainable yield(MSY), maximum economic yield(MEY) and F0.1 level of fishing mortality as the concept of optimal yield, and it theoretically shows that MSY is more appropriate for the optimal yield than MEY where prices increase even though MEY achieves the maximization of economic rent in a fishery assuming constant prices. And the paper presents several fisheries management tools and policies such as input controls, output controls and taxes. As the traditional approach to fishery management, input controls involve restrictions on the physical inputs into the production process(e.g. capital, time or technology) and output controls involve limits on the quantity of fish that can be landed. To introduce user cost into the harvest decisions of rent-seeking fishers, taxation, as a bioeconomic management policy of the fisheries, directly addresses the problems associated with the resource being unpriced. As most fisheries management plans, however, have increasing fisher income as an objective, taxes have not been introduced into any fisheries management policies despite their theoretical attraction.

Direct Economic Effects and Optimal Vessel Reduction Scales in Coastal and Offshore Fisheries (연근해어업 어선감척 적정 목표량 산정 및 감척효과 분석)

  • SHIN, Yong-Min;KIM, Jin-Sang;LEE, Jeong-Min;NAM, Jong-Oh
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.3
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    • pp.821-832
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    • 2015
  • The aims of this study are to estimate the optimal vessel reduction scales and these direct economic effects of coastal and offshore fisheries in the Republic of Korea. To estimate respectively optimal fishing efforts of individual fishery by species in coastal and offshore fisheries, we adopted appropriate fishing power of each species published by National Fisheries Research and Development Institute and also considered biological and socio-economic factors such as the bycatch rate, the profit rate, the efficiency of resource use, the average age of fishing vessel, the intention of vessel reduction, and the annual changes in vessels by other factors. The direct economic effects of the optimal vessel reduction in coastal and offshore fisheries based on maximum sustainable yield and 2/3 maximum sustainable yield was calculated by a cost-benefit analysis. This study showed that optimal reduction numbers of vessels engaged in coastal and offshore fisheries were 4,431 and 374 vessels and the direct economic effects in coastal and offshore fisheries were about 371.7 and 569.4 billion won and these NPV and BCR were 111.7 billion won and 1.65 and 342.6 billion won and 4.97 respectively.

Analyzing Potential Vessel Buyback Scale of Offshore Fisheries in Korea (우리나라 근해 어업의 잠재적 감척규모분석에 관한 연구)

  • Pyo, Hee-Dong;Choi, Sae-Him
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.311-322
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    • 2005
  • Fisheries buyback programs in Korea have been implemented since 1994, and their scales are estimated to be the present value of 930 billion won for the last 9 yens since 1994. The paper attempts to identify the patterns of each fish species, of which their yields can be steadily increased or significant]y decreased, and to evaluate its effective level and the optimal level for buyback programs by means of fishing capacity analysis. The paper distinguishes fish species, that there is no need to reduce the fishing efforts, such as anchovies, mackerels, squids, Spanish mackerels, and herrings, because MSY exceeds yields, from fish species to control overfishing such as file fish, yellow corvenias, young pollack, hair tail, snow crab, and pollack. The paper also suggests that 65% of the fishing efforts (total tonnages) should be cut back at the national aggregate level in order to restore fish stocks.

Analyzing Optimal Economic Fishing Efforts of the Coastal Snow Crab Gillnet Fishery (대게 연안자망어업의 경제적 적정 어구사용량 분석)

  • Kim, Do-Hoon;An, Heui-Chun;Lee, Kyoung-Hoon
    • The Journal of Fisheries Business Administration
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    • v.39 no.2
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    • pp.25-39
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    • 2008
  • The Korean government is in the establishment process of plan for managing fishing effort by setting up the maximum fishing gear usage per fishery type for the recovery of fishery resources, for the settlement of disputes between fishery sectors over fishing gears, and for the stability of fishing business condition. Especially in the setting up of the maximum fishing gear usage, economic standards as well as biological standards are being considered as a significant factor to promote the sustainable and economically viable development of fisheries. This study is, thus, to analyze the optimal economic fishing gear usage ($E_{MEY}$) as the most economically efficient one for the coastal snow crab gillnet fishery, one of the most controversial sectors in establishing the maximum fishing gear usage. The data of logbooks per trip were used for concentrating on the estimation of $E_{MEY}$ per trip because it was considered there were limitations of data available for analyses. As a finding drawn from the analyses, the optimal economic trap usage ($E_{MEY}$) of coastal snow crab gillnet vessels per trip has to be decreased by about 13%. That is, reducing the trip gillnet usage up to the level of $E_{MEY}$ can lead to the reduction of trip fishing costs, thereby resulting in the increased trip profits.

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Natural Dye Extraction from Merbau (Intsia bijuga) Sawdust: Optimization of Solid-Solvent Ratio and Temperature

  • Aswati MINDARYANI;Ali SULTON;Felix Arie SETIAWAN;Edia RAHAYUNINGSIH
    • Journal of the Korean Wood Science and Technology
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    • v.51 no.6
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    • pp.481-492
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    • 2023
  • The ecofriendly lifestyle has attracted considerable support for sustainable development. Natural dyes, as sustainable products, have become a research focus and development area for many scientists. Ecofriendly processing also supports circular sustainable development. This study effectively obtained tannins as a natural dye from merbau (Intsia bijuga) sawdust using water as an ecofriendly solvent. Merbau sawdust is an underutilized industrial waste. Temperature and solid-solvent ratio variations were performed to extract tannins from merbau sawdust. Temperature and solid-solvent ratio positively affected solution yield and tannin concentration. The optimal condition was identified using response surface methodology and experimental observations. A yield of 0.2217 g tannins/g merbau was obtained under the conditions of 333.15 K and 0.125 solid-solvent ratio. Extraction was controlled by convective mass transfer at the interface of solid particles.

A bioeconomic analysis of blackfin flounder Glyptocephalus stelleri fisheries management (기름가자미 어업관리를 위한 생물경제학적 분석)

  • CHOI, Ji-Hoon;CHOI, Wan-Hyun;KIM, Do-Hoon
    • 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.

A Study on the Optimal Emission of CO2 due to Climate Change : An Application for Large Purse Seine (기후변화가 대형선망 고등어 어업의 최적탄소배출량에 미치는 영향분석)

  • Choi, Jong Du
    • Ocean and Polar Research
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    • v.39 no.3
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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.

A Political-Economic Study on Fisheries Resource Rent and Rent-Seeking Behaviors (어업자원 지대 및 지대추구행위에 관한 정치경제학적 연구)

  • Park, Seong-Kwae
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.3
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    • pp.340-360
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    • 2005
  • Fishery resource rents(i.e. windfall gains or excess profit), which tend to lead a variety of important economic, social, political problems, have been a fundamental cause of unbalance between fishery resource use and management. Thus, there may exist several sorts of optimal level of resource utilization such as economic maximum sustainable yield, biological maximum sustainable yield, social optimum production, socio-political optimum yield, etc. The fishery resource use level seems to a large extent to be determined by the characteristics of fishermen's rent seeking structure. As well known, fishery resources as common properties have a characteristic of being difficult to establish private property rights. Therefore, their use rights are controlled by the permit and/or the license system. As a result, absolute or differential rents are formed by the changes in institutional arrangements. Rent problems are often transformed into serious socio-political issues when the rent in a given industry is much higher to a socially unacceptable extent than the average of other industries. However, individual fishermen or fishermen's groups tend to behave aggressively to change the existing fishery institutions towards maximizing fishery rents. These rent-seeking behaviors often tend to nullify fishery management schemes. The larger is the relative rent difference between fisheries and other industries, the more aggressive tend to be the rent-seeking behaviors in fisheries.

Studies for the Sustainable Management of Oyster Farms in Pukman Bay, Korea: Estimation of Carrying Capacity from Food Availability

  • Jeong, Woo-Geon;Cho, Sang-Man;Lee, Sang-Jun
    • Fisheries and Aquatic Sciences
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    • v.12 no.2
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    • pp.118-129
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    • 2009
  • To develop a sustainable management model for oyster farming in Pukman Bay, Korea, we estimated the carrying capacity for oyster farming using food availability data. Optimal culture densities were calculated to be 124-133 individuals per unit flux area ($m^2$) and 310-330 individuals per string. The present annual production is approximately 1,038 tons/year, which is 87% of the estimated maximum yield of 1,193 tons/year. Therefore, considering annual fluctuations and a critical buffer to reduce ecological impacts, the current level is within optimal conditions. During periods of increased water temperature, energy demand was largely met by high primary production. The food supply significantly decreased as the harvest season approached, and 10 out of 21 oyster farms had a deficient food supply for at least 1 month. Therefore, these farms (39% of the farms within the bay) exceeded optimal densities.