• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.6
• /
• pp.669-675
• /
• 2003

To increase fishery resources in coastal waters, juvenile fish and bivalves are artificially released every year in Korea. This study provides a methodology to estimate an optimal release quantity based on the carrying capacity of the receiving basins. Carrying capacity was defined by E.p. Odum's theory of ecosystem development as the upper limit of biomass, where total system respiration equals total primary production. The Ecopath trophic ecological model was used to determine carrying capacity in the surfzone ecosystem of Bangjukpo on the southern coast of Korea. Using a top-down control method, various biomasses of fish groups were given to the simulation, with primary production constant and no catch. The results showed that biomass of selected fish groups increased by two orders of magnitude, yielding a five-fold increase in overall consumer biomass. The resultant values are 10 times higher than those estimated in open seas. This can be explained by higher primary production in the Bangjukpo surfzone ecosystem. This method can be used for strategic releases and ecosystem management, particularly when based on an ecological background.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.43 no.3
• /
• pp.176-182
• /
• 2007

Fishing power, which means performance of fishing vessel or catchability of fishing gear, can explain using by fishing power index(FPI) to compare fishery efficiency among uniformity types of fishery that work during the fixed period in specific fishing ground. This research analyzed on their fishing power and catchability using comparing each sampled vessels of coastal trap fishery for common octopus. The results showed that they were no difference in amount of used trap and immersed time etc. in CPUE among sampled vessels, and had no correlation of catch production due to vessel's tonnage. Most vessel's FPI estimates but 3 vessels were higher than the averaged, and showed similar fishing power in general. And then, CPUE and FPI showed that 4 to 5 tonnage vessels would be superior to another, 4 tonnage vessels had also good catchability. Therefore, we estimated that 4 tonnage vessels had the most efficiency work for coastal trap fishery for common octopus.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.2
• /
• pp.200-206
• /
• 2015

The fishing industry has a negative effect on the environment due to greenhouse gas (GHG) emissions with the high use of fossil fuels, the destruction of underwater ecosystems by bottom trawls, reduction in resources by fishing, and altered ecosystem diversity. GHG emissions from fisheries were discussed at the Canc$\acute{u}$n meeting in Mexico in 1992 and are part of the Kyoto protocol in 2005. However, few studies have investigated the GHG emissions from Korean fisheries. To find a way to reduce GHG emissions from fisheries, quantitative analysis of GHG emissions from the Korean fishery industry is needed. Therefore, this study investigated the GHG emissions from the Korean Danish seine fishery using the life cycle assessment (LCA) method. The system boundary and input parameters for each process level are defined for the LCA analysis. The fuel-use coefficient of the fishery is also calculated. The GHG emissions from the representative fish caught by the Danish seine fishery are considered and the GHG emissions for the edible weight of fishes are calculated, considering consumption in different areas and different slaughtering processes. The results will help to understand the GHG emissions from Korean fisheries.

• The Journal of Fisheries Business Administration
• /
• v.43 no.1
• /
• pp.11-18
• /
• 2012

This study is aimed to estimate a dynamic productive efficiency by vessel of large purse seine fishery and analyze changes of them over times using a window/DEA method. In addition, based on estimation results, it aims to suggest production management implications for an viable development of fisheries. Results indicated that an annual efficiency change of large purse seine fishery was estimated at 0.77 for 2007~2008, 0.83 for 2008~2009, and 0.77 for 2009~2010, showing a decreasing trend. As returns on sales of vessels of large purse seine fishery showed a decreasing trend, the degree of efficiency of a vessel might be closely related to the fishing profitability. The Window/DEA method was used in this study to estimate the efficiencies of vessels for large purse seine fishery. This method is well known and widely used to analyze the dynamic efficiency and it can provide useful implications for management of input factors. As a limitation of this study, it was not able to provide detailed management ways to reduce inefficiencies. However, they can be investigated with data on managerial factor, human factor, distribution factors as a future study.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.54 no.1
• /
• pp.32-37
• /
• 2018

The aim of this study is to investigate influence of moon light to the fishing of squid jigging fishery in the southwest Atlantic Ocean based on analyses of date taken from 127 vessels in Falkland fishing ground by squid jigging fishery from 2010 to 2015. Catch and CPUE were analyzed between the new moon and full moon phases. Catches of the new moon phase were higher than those of the full moon phase by 7.6% and CPUE expressed in mt/day-vessels and mt/line-day were also higher by 18.2%, 18.2% respectively. However, as a result of statistical analysis at a significance level of p > 0.05, no significant statistical differences in catch, mt/day-vessels and mt/line-day were found between the new moon and the full moon as a result of statistical analysis at a significance level of p > 0.05.

• Fisheries and Aquatic Sciences
• /
• v.25 no.6
• /
• pp.335-349
• /
• 2022

To optimize the hydrolysis conditions in the production of antioxidant hydrolysates from tuna cooking juice concentrate (TC) to maximize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, TC containing 48.91% protein was hydrolyzed with Alcalase 2.4 L, and response surface methodology (RSM) was applied. The optimum hydrolysis conditions included a 2.2% (w/v) Alcalase concentration and 281 min hydrolysis time, resulting in the highest DPPH radical scavenging activity of 66.49% (0.98 µmol Trolox/mg protein). The analysis of variance for RSM showed that hydrolysis time was an important factor that significantly affected the process (p < 0.05). The effects of different drying methods (freeze drying, hot air drying, and vacuum drying) on the DPPH radical scavenging activity and amino acid (AA) profiles of TC hydrolysate (TCH) were evaluated. Vacuum-dried TCH (VD) exhibited an increase in DPPH radical scavenging activity of 81.28% (1.20 µmol Trolox/mg protein). The VD samples were further fractionated by ultrafiltration. The AA profiles and antioxidant activities in terms of the DPPH radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power, and ferrous ion chelating activity were investigated. Glutamic acid, glycine, arginine, and cysteine were the major AAs found in the TCH fractions. The highest DPPH radical scavenging activity was found in the VD-1 fraction (< 5 kDa). The VD-3 fraction (> 10 kDa) exhibited the highest ABTS radical scavenging activity and ferric reducing antioxidant power. The ferrous ion chelating activity was the highest in VD-1 and VD-2 (5 to 10 kDa). In conclusion, this study provided the optimal conditions to obtain high antioxidant activities through TCH production, and these conditions could provide a basis for the future application of TCH as a functional food ingredient.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.4
• /
• pp.355-358
• /
• 2001

This paper presents case studies on the multi-species fisheries in Korean waters. Multi-species fisheries were divided into two types, that is, multi-species by a single fishery and single species by multiple fisheries. For the case of the multi-species by a single fishery, a multi-species yield-per-recruit model was applied to the Korean pair trawl fishery, which exploits demersal fishes such as, hairtail (Trichiurus lepturus), small yellow croaker (Pseudosciaena polyactis), white croaker (Argyrosomus argentatus) and pomfret (Pampus echinogaster). The overall fishing mortality ($F_x$) values for the multi-species was estimated and compared to the spawning potential ratio ($F_{x\%}$) val ues estimated from the spawning biomass-per-recruit model.

• The Journal of Fisheries Business Administration
• /
• v.31 no.2
• /
• pp.133-153
• /
• 2000

During the last several decades, Korea has been regarded as one of the fastest growing economies in the world. However, the small size of national land has not met the vigorous demand for land necessary to develop economic infra-structures such as large-scale harbors airports and highways. In order to satisfy the growing demand for land, the Korean government and industry have implemented the national land development programs to reclaim land from the sea fur the several decades. It is certain that these land development programs have resulted in a lot of property disputes between fishermen and public project administrators. This paper is to develop a quantitative model to estimate compensation for damages or restriction of charted fisheries resulting from large-scale public projects. In this paper, the compensation model is derived by using cost-volume-profit analysis framework because the compensation for charted fisheries basically depends on the factors such as the costs, production volume, profit of charted fisheries damaged or restricted by public projects. The model shows that the compensation for damages or restriction of charted fisheries is determined by the average annual profit, damage duration period, and the degree of fishery damages. In addition, the degree of fishery damages measured by the ratio of lost profit to annual average profit turns out to be determined by the following factors: annul profit, unit variable cost, decrease in production volume, the rate of increase in variable cost, and a change in fixed cost. Furthermore, this parer discusses the nam issues related to practices and regulation of the compensation for fishery damages in the current Fishery Act of Korea and suggests some appraisal methods which will be able to lead to theoretically correct and fair compensation for fisheries damages resulting from large-scale public projects.

• The Journal of Fisheries Business Administration
• /
• v.36 no.1 s.67
• /
• pp.103-120
• /
• 2005

This study aims to examine the change of fish market(魚物市場) and inland brokers(客主, kaegju) on Gunsan(群山), (1899-1919). The increasement of productive capacity in the agriculture and the development of exchange economy in the late period of Chosun Dynasty activated the distribution of fishery products. As a result, the inland brokers who participated in the production and distribution of fishes grew largely. They made the basement of fishery modernization by providing the funds for the fisheries and making the national distribution network. But Japanese fishermen began to hold the domestic market as the Japan government supported legislatively and economically after the opening ports of Korea. On the contrary, the distribution of fishery products had the characteristics different from the production of some. The case of Gunsan which opened in 1899 showed these characteristics as Gunsan is a short distance from Kangkyung(江景), one of three biggest markets and was a base of fishery, That is to say, though the fishery merchants from Japan set up 'a fish market'(魚市場), they didn't hold the sales network on Gunsan, Because the inland brokers on Gunsan had a sales network and began the socio-economic movement. It goes without saying that the instability of price, the difficulties of charge and the racial taste difference in fish made the fish sales from Japan confronted with the difficulties. After Japanese Imperialism enforced the Company Law, the Market Regulation, the Chamber of Commerce Law before or after 1910, Korean inland brokers were disprited and Japanese 'fish market' began to grow largely. These phenomena appeared on Gunsan, too. Especially, the opening of a railway was the main factor which strengthened Japanese 'fish market'. After 1915, Japanese 'fish market' on Gunsan defeated the distribution network of inland brokers.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.22 no.4
• /
• pp.196-200
• /
• 1989

Fishery production of topshell in Cheju-do has been rapidly decreased in the last few years. To investigate the origin of this problem and estimate maximum sustainable yield (MSY) and catch per unit effort (CPUE) of topshell in Cheju-do, a survey has been done ysing the statistical data for 19 years (1968-1986) of topshell production in Cheju-do and data for 3 yea.5 (1984-1986) from an fishery village, Tonggui-ri, Pukcheju-gun, Cheju-do. Maximum sustainable yield of topshell in Cheju-do assumed to be 2,500-2,800 metric tons(M/T) per year. The annual fishery productions of topshell from 1982 to 1986 were 3,368, 3,649, 3,308, 3,136, and 1,400 M/T, respectively. These results show that topshell had been over-fished during 1982 to 1985. Because of the over-fishing, production sharply decreased down to 1,400 M/T in 1986. Total annual production of topshell in Tonggui-ri is a little less than one Percent of that of Cheju-do. To achieve this production, over the half of resistered diving women in this village have been worked. To estimate catch per unit effort of topshell in Cheju-do, it seems better to use the data which is the number of diving women who have been worked for certain period of time than the number of working days in the same period of time.