• Journal of Marine Life Science
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• v.4 no.2
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• pp.70-80
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• 2019

Ichthyofauna and community structure of fish were studied for two fisheries resource reserves, Chuncheon reservoir and Andong reservoir from 2017 to 2018. Fish were sampled 8 times at each reservoir. In Chuncheon reservoir, total number of fish sampled was 1,197 representing 34 species and 13 families. Dominant species and sub-dominant species were Lepomis macrochirus (23.2%) and Zacco platypus (17.4%), respectively. In Andong reservoir, total number of fish sampled was 1,393 representing 24 species and 9 families. Dominant species and sub-dominant species were L. macrochirus (15.7%) and Carassius carassius (15.2%), respectively. The diversity index of two sampling site increased compared to previous investigation. The evenness index was not changed much in Andong reservoir but increased in Chuncheon reservoir. Ichthyofauna and community structure of fish at sampling sites in both reservoirs maintained stable except high proportion of exotics species with needed to be reduced by consistent effort. For better fish population in these communities, however, various efforts such as seed stocking and installment of artificial spawning ground should be provided to these reservoirs.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.1
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• pp.7-19
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• 2019

This study was conducted in order to improve opening efficiency of the miniaturized small-scale net for anchovy boat seine gear to reduce the fleet size. Field experiment was performed to observe geometry of nets by catcher boats. When the distance between the two ships was 150, 300 and 450 m and the speed of towing nets was 0.6, 0.9, and 1.2 kt, the vertical opening and actual opening of each part of the miniaturized small-scale net was as follows: the front part of the wing net, 6.8-9.5 m, 45-63%; the middle part of the wing net, 16.1-30.7 m, 34-65%; the entrance of the inside wing net, 21.6-41.2 m, 44-84%; the square and bosom, 17.4-34.0 m, 38-75%; the entrance of the body net, 16.5-29.4 m, 36-64%; the entrance of the bag net, 14.5-21.9 m, 70-106%; the flapper, 6.7-7.7 m, 81-83%, and the end of the bag net, 8.6-10.9 m, 64-81%. The tension of towing nets was measured to be 2,734-6,812 kg approximately, which indicates that the fleet can tow nets with 350 hp, the standard engine horse power. The fishing operation time was shortened comparing to existent net with the large-scale buoy attachment operation. It was also possible to operate the ship without fish detecting boat.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.500-513
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• 2023

The effects of prolonged photoperiod (additional night lighting) were investigated on the production of Ocimum basilicum (lemon basil) and fish/crayfish raised in a nutrient film technique aquaponic system. Hybrid lemon fin barb and red claw crayfish juveniles were co-cultured with O. basilicum and subjected to 12 h of ambient natural daylight and additional 0, 4, 8, and 12 h of night lighting for 14 weeks (two batches of 7 weeks each). The water quality parameters and the performance characteristics of the fish/crayfish/plant were evaluated, and the nutri- ent uptake (nitrogen, phosphorus, and potassium) in the system by the three organisms was also measured. The fish growth performance showed no significant differences (p > 0.05) in all the growth parameters measured across the treatments. The body proximate and nitrogen, phosphate, and potassium (NPK) composition of the fish and crayfish were not significantly (p > 0.05) different across the treatments. Similarly, there was no significant difference (p > 0.05) in the NPK uptake by the fish and crayfish across the treatments. The plant growth performance showed that there were no significant (p > 0.05) differences in the plant growth parameters measured, except for % plant height gained in the 12 h-light treatment (403.2 ± 26.0%) which was significantly (p < 0.05) higher than other treatments and cycles. Hence, this study demonstrat- ed that varying supplementary night lighting has no significant effect on the growth performance of O. basilicum, hybrid lemon fin barb, and red claw crayfish. This study, therefore, suggests that supplementary night lighting should not be considered for O. basilicum production as it does not significantly improve the performance characteristics of the plant nor the fish co-cultured with it in a polyculture aquaponic system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.38-42
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• 2000

Thig study was conducted to get a knowledge on chemical components of the cooked tuna bones (skipjack tuna bone and yellowfin tuna bone) as a food resource. The crude protein of tuna bone was around $29{\%}$ on the dry basis. The imino acid content (193 imino acid residues /1,000 amino acid residues) of collagen extracted from yellowfin tuna bone was higher than that (173 imino acid residues /1,000 amino acid residues) of collagen extracted from skipjack tuna bone, however, it was lower than that of collagen extracted from animal bone. The content and the ratio of unsatuated fatty acids in lipid extracted from yellowfin tuna bone were higher than those of lipid extracted from skipjack tuna bone, but they were lower than those of squid viscera oil. The contents of calcium and phosphorus as the major components of the tuna tone were 36.5 g and 17.2 g in 100 g ash in the skipjack, respectively, and 38.0 g and 18.7 g in 100 g ash in the yellowfin, respectively. It was concluded from these results that tuna bones could be effectively utilized as a mineral source.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.478-482
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• 2001

This study was conducted to get a knowledge on food components of cuttle bone (CB) as a food resource. The yields and ash contents of CB were about $7.5\%$ on whole cuttle fish and about $90\%$ on dry basis, respectively, The contents of heavy metal might not invoke health risk in using food resource, The major mineral of CB was calcium as about $22\%$ in content. The yields, proximate compositions, heavy metal and mineral contents were not significantly different between domestic and imported CB. Judging from X-ray diffraction pattern, most of calcium in CB was present as a form of calcium carbonate (CC), and scanning electron micrograph showed irregular form. Buffering capacity of CB showed strongly at pH 7, and its pattern was the same as shown in that of CC, And CB solution showed a very high degree in turbidity comparing to that of CC solution. The solubility of CB was superior to that of CC, but inferior to those of calcium powders on the market, It was concluded from above results that CB could be effectively utilized as a calcium source.

• Environmental and Resource Economics Review
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• v.15 no.1
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• pp.71-94
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• 2006

Reducing fishing capacity is one of hot issues in the world fisheries. Increased fishing capacity causes not only fish stocks to be depleted, but also additional fishing costs to be incurred, resulting in reductions of fishing profits. In order to achieve a sustainable and profitable development of fisheries, it is inevitable to reduce fishing capacity. For this reason, FAO adopted 'the International Plan of Action for the Management of Fishing Capacity' and recommended member countries to estimate fishing capacity and to implement the policy to reduce fishing capacity. This study is aimed at measuring fishing capacity of Large Purse Seines Fishery using a Data Envelopment Analysis (DEA). The DEA result showed that the practical catch of large purse seine fishery in 2003 was 158,662 tons, but the capacity output for current input was 318,397 tons. The capacity utilization is about 50%, it is obvious the capacity did not utilize enough. The sensitivity analysis on DEA results indicated that the number of ships (including tonnage and horse power) should be scrapped by 50% or days fished should be reduced by 63% if the present catch remained. In addition, if the catch remains at the MSY base level of large purse seines, the analysis suggested that the number of ships (including tonnage and horse power) should be reduced by 30%, otherwise days fished should be reduced by 60%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.1-8
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• 2006

For the effective utilization of tuna processing byproducts such as roes of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacores) as a food resource, the roes of skipjack and yellowfin tuna were examined on food component characteristics and also compared to those of Alaska pollack (Theragra chalcogramma). The concentrations of heavy metal in both roe of the skipjack and yellowfin tuna were below the reported safety limits, therefore, these roes appeared to be safe as a raw material for food resource. The contents of crude protein were 21.4% in the skipjack tuna roe and 21.5% in the yellow fin tuna roe, which showed to be the major component in tuna roes. The prominent amino acids of total amino acids were aspartic acid, glutamic acid, leucine and lysine, and these amino acids were comprise to be 38.4-41.2% of total amino acid in both tuna roes. The total lipid content were 2.1 % in the skipjack tuna roe and 2.0% in the yellofin tuna roe. The major component of total lipid was found to be triglyceride in both tuna roes (skipjack tuna roe, 93.3%; yellow fin tuna roe, 92.0%), which was high in the compositions of 16:0, l8:1n-9, and 22:6n-3. The content of DHA in total lipid of the tuna roes (skipjack tuna roe, 29.9%; yellowfin tuna roe, 36.3%) were higher than that of Alaska pollack roe (18.1%). Based on the results of the proximate composition, mineral, amino acid and lipid characteristic, roes of skipjack tuna and yellowfin tuna showed potential as a raw material for food.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.897-914
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• 2010

The translog cost function of Korean Walleye pollock fishery is used to examine the impact of surface water temperature change led by global climate change. Catched of walleye pollock are very sensitive to water temperature and material cost. Elasticities of production to water temperature are -9%, significantly lower than we expected. There may be alternative explanations for the productivity decrease, including the possibility of overfishing and water pollution. However, the impact of climate change is obvious and inevitable. Therefore the government may encourage local fishermen to change from current cold water to warm water fisheries. Moreover continuos monitoring for the possibility of illegal activities at the East Sea. Finally, collaborated political efforts may be needed among the nations in the East Sea to conserve a Walleye Pollock fishery.

• Ocean and Polar Research
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• v.45 no.3
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• pp.173-183
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• 2023

The barren ground phenomenon in Korea began to occur and spread in the southern coast region and in Jeju Island in the 1980s, and since the 1990s, the damage has become serious in the east coast region as well. Korea has enacted the fisheries resource management act to manage such barren ground through the installation of sea forests among projects for the creation of fishery resources. Until now, projects related to the identification of the cause of barren ground have focused on the density of crustose coralline algae, sea urchins and seaweed, so the original cause of barren ground has not yet been identified. In order to manage barren ground, it is necessary to identify the cause of barren ground. To identify these causes, it is necessary to comprehensively consider i) studies on spatial characteristics such as rock mass distribution, slope and water depth, ii) studies on ecological and oceanographic characteristics such as water temperature, salinity, El Niño, and typhoons etc, iii) studies on organisms such as crustose coralline algae, macroalgae, and sea urchins, and iv) studies on coastal use such as living and industrial sewage inflow. Next, as with regard to legislative policy proposals , it is necessary to prepare self-management measures by the government, local governments, and fishermen as well as address management problems related to the use of sea forests by fishermen after their creation . In addition, when creating a sea forest, a management model for each resource management plan is required, and evaluation indicators and indexes that can diagnose the cause of barren ground and guidelines for barren ground measures should be developed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.628-638
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• 2023

Maritime Autonomous Surface ships(MASS) are gradually gaining importance. Until fully autonomous ships are developed, they will likely be controlled by remote operators who are based in a Remote Operations Center. However, there is currently no internationally or domestically established licensing for them. This issue can potentially pose a risk to navigation safety due to operations being handled by unqualified remote operators. We conducted a literature review and proposed criteria for the adoption of a licensing system for remote operators. We have futher offered alternatives to integrate this license into the existing officer licensing system, and analyzed them using Analytic Hierarchy Process(AHP). Subsequently,, theprimary need to enact legislation for remote operators is observed. The most preferred approach is to include the occupation of a remote operator in the Ship Officer Act, Article 4: Occupational Categories and Class of Licenses. Therefore, it would be logical for the organizational structure of the Remote Operation Center to mirror the traditional Bridge Resource Management. This study will contribute to the efficient training of remote operators and the safe navigation of autonomous ships with a focus on human resource management.