• Journal of Environmental Science International
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• v.23 no.3
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• pp.483-492
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• 2014

DNA damage such as genotoxicity was identified with comet assay, which blood cell of a marine parrot fish (Oplegnathus fasciatus) was exposed to an acidified seawater, lowered pH gradient making of $CO_2$ gas. The gradient of pH were 8.22, 8.03, 7.81, 7.55 with control as HBSS solution with pH 7.4. DNA tail moment of fish blood cell was $0.548{\pm}0.071$ exposed seawater of pH 8.22 condition, on the other hand, DNA tail moment $1.601{\pm}0.197$ exposed acidified seawater of pH 7.55 lowest condition. The approximate difference with level of DNA damage was 2.9 times between highest and lowest of pH. DNA damage with decreasing pH was significantly increased with DNA tail moment on blood cell of marine fish (ANOVA, p < 0.001). Ocean acidification, especially inducing the leakage of sequestered $CO_2$ in geological structure is a consequence from the burning of fossil fuels, and long term effects on marine habitats and organisms are not fully investigated. The physiological effects on adult fish species are even less known. This result shown that the potential of dissolved $CO_2$ in seawater was revealed to induce the toxic effect on genotoxicity such as DNA breakage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.906-912
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• 2014

The study of fish robot is a main subject that are related with the propulsive force comparison using a varying amplitude and frequency for body and tail motion trajectory, and the quick turn using a proper trajectory function. In this study, when a fish robot thrusts forward, feedback control is difficult to apply for a fish robot, because body and tail joints as a sine wave are rolled. Therefore, we detect the virtual position based on the path of the fish robot, define the angle errors using the detected position and the look-ahead point on the given path, and design a controller to track given path. We have found that the proposed method is useful through the computer simulations.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.75-90
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• 2003

When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.62-67
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• 2006

The maintenance of continuity on food processing has created a need for the rapid reinstatement of many types of frozen fish to an ambient temperature and good condition. A number of thawing methods are in current use have also several disadvantages in thawing time. discoloration mass loss caused by drying, capital and running cost. These damages are, it is claimed, either eliminated or improves by the vacuum system. An experimental study on the thawing for hair tail and Yellow croaker by the vacuum system were carried out. The Yellow croaker thawing time with this vacuum system took out 170 minutes to reach from $-10.3^{\circ}C\;to\;-0.8^{\circ}C$ at 20mmHg abs. and hair tail thawing time 220 minutes to reach from $-12.2^{\circ}C\;to\;0^{\circ}C$ at 20mmHg abs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.33-40
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• 1987

This paper aims to study the browning reactions of lipid originated carbonyl compounds with nitrogenous compounds in dried fishes, flounder, mackerel, shrimp, hair tail fish, and whale. The major fatty acids in the flounder, the mackerel, the shrimp, and the hair tail fish were $C_{16:0},\;C_{18:1},\;C_{22:5},\;C_{22:6}$, and those in the whale meat were $C_{16:0},\;C_{18:1},\;C_{20:4}$. The nonpolar lipid contained higher percent of $C_{18:1}$ while the polar lipid contained higher percent of $C_{22:6}$. When those fishes were dried and stored, the PoV and CoV were high in the mackerel and the hair tail fish, whereas low in the flounder, the shrimp, and, the whale. The browning was developed more rapidly in the lipid soluble fraction than in the water soluble fraction of each sample, and the loss of available lysine and polyenoic acids were accompanied. The polyunsaturated fatty acids markedly decreased, particularly, in phospholipid than in neutral lipid, and $C_{20:5},\;C_{22:5},\;C_{22:6}$ were rapidly decreased during the storage.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.232-239
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• 2001

For the purpose of providing the basic data on the improved fishing gear and the man power saving, which contribute to enhance fishing efficiency of set net in the coast of Jeju Island, this study analyzed the catch of two fishing place for the past 3 years in order to compare the fishing efficiency between rectngular set net and pound net, which have been used for fishing with being attached to the set net fishing place in coast of Jeiu Island, Thereby the result is as follows ; 1. When using pound net, the total amount of catch during 1997 to 1999 was 2 times more than that of when using rectangular set net. 2. When using Pound net, the catch of squid, mackerel, rabbit fish and Yellow tail during 1997 to 1999 was 1.8 times more than that of when using rectangular set net.. 3. In case of rectangular set net, CPUE marked 10.1㎏ with horse amckerel, 20.5㎏ with squid, 18.0㎏ with rabbit fish and 2.2㎏ with Yellow tail, and in case of pound net, CPUE marked 57.5 ㎏ with horse mackerel, 30.0㎏ with squid, 25.0 with rabbit fish and 4.7㎏ with yellow tail, and on the whole CPUE of poind net marked higher. 4. In case of rectangular set net, the catch ratio for fishing operation marked 64% with horse mackerel, 79% with squid, 39% with rabbit fish and 14% with yellow tail, and in case of pound net, the catch ratio fishing operation marked 18% with horse mackerel, 85% with souid 40% with rabbit fish and 14% with yellow tail, and accordingly it showed the result that the catch ratio for fishing operation was higher with the case of rectangular set net, but higher with the case of pound net.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.45-55
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• 1986

This paper aims to study the reactions of lipid or oxidized lipid with protein during drying and storing hair tail fish(Trichurus lepturus) and flounder(Kanakius kitaharai) being generally consumed as dried seafood products in Korea and their influence on the drop of in vitro protein digestibility of these fish meat. The results of the study are as follows: The digestibility of the raw materials of flounder and hair tail fish was 87.63% and 86.08% respectively, and that of sundried and hot air dried materials went down $1{\sim}2$ percent with drying process. But in case of defatted and sundried materials, the rate increased 85.15% and 87.15% respectivley. After 30 days of storage, the digestibility decreased in all materials, and hot air dried meat showed a significant decrease. Trypsin indigestible substrate (TIS) contents of flounder and hair tail fish, in case of raw materials were 0.88 and 0.96mg/g. solid repectiveiy and in case of defatted and sundried materials, TIS contents showed a low increase and digestibility showed a high increase. Brown pigment formation had a wide range of increase in case of the sundried and hot air dried materials and it was increased with duration of storage and temperature. The major fatty acids in the fats of hair tail fish and flounder were $C_{18:1},\;C_{16:0},\;C_{22:6}\;and\;C_{16:1}$ and rate of unsaturated to saturated fatty acids was 79.2:20.8 for flounder, 67.8:32.2 for hair tail fish. After 30 days of storage at room temperature. saturated fatty acids increased compared with the raw materials while unsaturated fatty acids showed a tendency to decrease. Avaialble lysine of hair tail fish was higher than that of flounder and both of them lost about 8.23% of that in raw materials after 30 days of storage.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.924-929
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• 2015

In this paper, we suggest a phase difference algorithm inspired by weakly electric fish. Weakly electric fish is a fish which generates electric field though its electric organ in the tail. The weakly electric fish search for prey and detect an object by using electrolocation. The weakly electric fish have Jamming Avoidance Response (JAR) to avoid jamming signal. One of pulse-type weakly electric fish Gymnotus carapo also have JAR to reduce the probability of coincidence of pulses. We analyze this response signal and design the phase difference algorithm. We expect that simple algorithm inspired by weakly electric fish can be used in many engineering fields.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.254-267
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• 1993

Fatty acid contents of 59 food items which are major fat sources in Korean diet were analyzed. The contents of EPA and DHA in fish were 0.02-2.66g and 0.02-3.01g per 100g edible portion, respectively. Items with high amount of EPA and DHA were canned Sardine, Mackerel, Mackrel pike, Atka-fish, Hair tail, Conger eel and Herring. But white fish such as Croaker, Gindaro, Flounder and frozen Alaskan pollack contained less than 0.1g of EPA and DHA per 100g edible portion. Other sources of n-3 fatty acid were perilla oil, rapeseed oil, soybean oil and walnuts all of which contained relatively high amounts of linolenic acid.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.74-77
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• 1995

Seahorse fish, Hippocampus trimaculatus Leach, collected in the Chriu Island and Dolsan Island, Korea is recorded for the lent time from Korea. Hippocampus trimacufctus is easily distinguishable from the other species of this genus, in having 20 dorsal fin raws, 17 anal fin rays, 11 trunk rings and 41 tail rings. H. tukokurae reported from Japan is a junior svnonsnn of H. trimacufatus.