• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.387-395
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• 2015

Starfish, a species of Echinoderm, is widely known as a predator on benthic invertebrate. A series of fishing experiments was carried out in the western coastal waters of Korea from September, 2011 to November, 2012, using the drum-shaped pots of different mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm) to describe the composition of the catch species and the mesh selectivity of the pot for starfish. Some species including fish, crab, and starfish were caught in the experimental pots. The SELECT (Share Each Length's Catch Total) method was applied to describe the selectivity of the pot for starfish Asterina pectinifera. The master selection curve was estimated to be s(R) = exp(10.358R-4.086) / [1+exp(10.358R-4.086)], where R is the ratio of arm length to mesh size. The relative arm length of 50% retention was 0.395, and the selection range was 0.212. The results should be helpful to understand the relationship between the catch size of starfish and the mesh size of pot.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.227-237
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• 2013

In Jeju Island, red sea bream is mainly caught by long line with a live squid as bait. The movements of artificial jigs in the fishery are supposed to be an important factor for catching the target organism as well as bait. To develop new fishing method for long line fishery, movements of the bait which was squid were tried to be characterized. In a water tank experiment, a live squid was hooked by a fish hook attached to a model long line. And then movements of squids in the water tank were recorded for 20 minutes by a video camera. Recorded movement of the squid was just periodically up-and-down moving, with a dominant frequency of 0.125Hz, and amplitude of 10.8cm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.292-298
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• 2020

The effects on the size selectivity for Muraenesox cinereus caught by coastal longline fishery were investigated in the southern coast of Korea from June 2 to 17, 2019. Four sizes of hooks (sizes 15, 17, 18 and 19) and two sizes of bait (sizes 9.9 g and 18.3 g) were tested in seven and three fishing trials, respectively. Such results revealed that smaller hook and bait size improved capture efficiency. And our results demonstrate that there was no significant size selectivity effect for hook size (ANOVA, p>0.05), but small bait improved on catching smaller fish (ANOVA, p<0.05).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.2
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• pp.88-98
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• 2011

Experimental fishing was carried out to compare the catches of main species and bycatch according to the codend mesh size (raschel, 15mm, 25mm, 35mm, 45mm) of stow net on anchor in the coastal waters of Seocheon after manufacturing five kinds of fishing gears and commercial fishing boat (7.93 tons) was used for it. Anchovy (Engraulis japonicus), southern rough shrimp (Trachysalambria curvirostris), beka squid (Loligo beka), cuttle fish (Sepia esculenta), swimming crab (Portunus trituberculatus) were dominant on the five kinds of experimental fishing gears. Southern rough shrimp was caught from all kinds of fishing gears and catches of anchovy was highest in the raschel codend, southern rough shrimp for 15mm, 25mm, 35mm codend and beka squid for 45mm codend. Bycatch proportion against total catches was 623,376g (28.7%) for 2,171,844g in raschel, 11,932g (1.7%) for 704,451g in 15mm, 3,616g (1.6%) for 221,432g in 25mm, 9,276g (4.9%) for 191,052g in 35mm and 2,724g (5.3%) for 51,431g in 45mm.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.3
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• pp.373-389
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• 2009

The aims of this study are to examine urgent problems for reorganization into future-proof large purse seine fisheries in order to positively cope with rapidly changing domestic and foreign fisheries circumstances. First, this paper provides current situations of the large purse seine fisheries. The current situations of it are composed of fisheries influence such as vessel number, vessel power, and fisher number, use of resource and fishing places, and changes in products and sales of species caught by the large purse seine. Secondly, this paper reviews current problems of the large purse seine fisheries including cost reduction and increase of value added. Thirdly, this paper suggests basic development direction and countermeasures for strengthening competitiveness of the large purse seine fisheries. In conclusion, urgent problems of the larger purse seine fisheries can be summarized as inefficiency of distribution structures and retarded landing system and facilities as well as the worse of profitability according to shrink of fishing places, reduction of products, lack of workers, and increase in oil price. To solve the urgent problems, the large purse seine fisheries should be changed into an industry with low cost and high efficiency, and also need to introduce of new production system, strengthen autonomous management of natural resource, and increase in value added to products.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.3
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• pp.407-415
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• 2014

Fish was caught by a set net in Gwideok, Jeju island that was studied to determine monthly variation of species composition and catch from May 2005 to October 2006. Total catch was 54 species, 44,118 individuals, and 2,152,423.7 g during survey period. Dominant species were Trachurus japonicus and Siganus fuscescens that held 91.3% of total individuals and 71.3% of total abundance. The highest individuals and abundance of catch were in July 2005, and the lowest individuals and abundance of catch were in October 2006 and in October 2005, respectively. As the result, temporal change in abundance have corresponded with changing water temperature.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.301-307
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• 2018

This paper deals with the development of the high frequency thawing machine. The fishery products caught over the world are kept frozen to maintain freshness. These fishery products require thawing before they are sold to customers as food. However, the thawing process can cause freshness reduction, drip coming out, quality deterioration, discharging polluted water, as well as a lot of space and time. The high frequency thawing machine developed to solve this problem has a narrow space, a short thawing time and a small drip. The developed high frequency thawing machine can be used in many fields such as fish processing plant, livestock processing plant. This paper describes the design of the high frequency thawing machine by developing the high frequency generator, development of the controller, and the design of mechanism, and shows the superiority of the high frequency thawing machine by the performance evaluation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.279-289
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• 2023

The United States enforces the seafood import regulations so-called the Marine Mammal Protection Act (MMPA), and by 2023, all exports of aquatic products and processed fish products by fisheries which have not obtained an "Comparability Finding" from the National Oceanic and Atmospheric Administration will be completely banned. Therefore, to respond to the US MMPA, it is critical to identify technologies and methods used in worldwide for reducing bycatch of marine mammals. In particular, marine mammals are frequently caught in five fisheries (trawl, gill net, trap, stow net and set net) in Korea, which is facing a great challenge. This study presented bycatch reduction methods by five fisheries, classified the methods by country, and suggested appropriate reduction methods which can be applied in Korea.

• Journal of Aquaculture
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• v.7 no.4
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• pp.189-205
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• 1994

Formerly, adult-tiger puffer, Takifugu rubripes with ova caught in the sea, were used for seedling production. But it was difficult to secure naturally-ripened adults. For the purpose of adult tiger puffer in captivity, this study was carried out. To determine the growth 220 tiger puffers hatched in 1990 (3-year-old) and 1991 (2-year-old) were used. For spawning and egg incubation leading to fry development, eggs were stripped from tiger puffers hatched in 1988 (5-year-old) and 1990 (3-year-old) through human chorionic gonadotropin (BCG) treatments. In May, 1993, mean body length and mean body weight of 2-year-old tiger puffer were $30.72\pm1.35cm\;and\;1,048\pm228 g,$ and that of 3-year-old tiger puffers were $36.02\pm1.17cm$ and $1,402\pm66g$ respectively. The relationship between body length (L) and body weight (W) of 2-year-old the tiger puffers during the experiment period was represented as $W\;=\;1.7892L^{31524}\times10^5$ (r= 0.9436) and that of 3-year-old, $W=\;3.2840L^{36099}\times10^6$ (r= 0.9070) respectively. The GSI in female 2-year-old-fish changed from $0.23\times0.l2\;to\;0.74\pm0.08$, during the experiment period, and in male it didn't change remarkably until November, but thereafter it increased and showed a peak of $8.69\pm5.09$. The GSI of 3-year-old-fish showed a peak of $8.05\pm5.58$ in April in female and $12.65\pm4.60$ in May in male. The change of HSI in 3-year-old-fish was correlative to the change of GSI, but in 2-year-old-fish it was little correlative. In female gonad of 2-year-old tiger puffer, the mature oocytes reached $350{\mu}m$ in April, but thereafter they didn't spawn and became atrophied. But in male gonad, a great number of spermatozoa were crowded in the testicular lobuli in April. Female gonad of 3-year-old tiger puffer had the mature oocytes of 650 pm in March and the ripe oocytes, $900{\mu}m$ in April. Male testis development was similar to that of 2-year-old-fish. Egg-stripping after hormone treatments was possible past 139 hours and 142 hours from each of two 5-year-old-fish (500IU/kg, BW), and after 114 hour from a 3-year-old-fish (1,000 IU/kg, BW) under water temperature $16.3\~17.8^{\circ}C$. Eggs stripped amounted was 650 g and 400 g from two 5-year-old-fish and 610 g from the 3-year-old-fish, and fertilization rates were $98.0\%,\;97.4\%\;and\;96.5\%$ respectively. All the hatched larvae devloped into normal fry.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.196-206
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• 2005

The fish community in the mid-upper region of Gam Stream was examined seasonally from 2001 to 2003 in order to perform an environmental impact assessment prior to a construction of Gamcheon Multipurpose Dam. Additional investigation was conducted in August 2004 to confirm the fish fauna reported and to examine the ecological characteristics of Zacco temminckii population. The total number of fish caught from the study sites was 1,081 fish representing 5 families 14 species. There were 6 Korean endemic species including Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala, but no endangered or vulnerable species were found. Length-weight relation, condition factor (K) and relative condition factor (Kn) of Zacco temminckii were compared by the study sites and stream. The equations based on length-weight relation in Buhang and Gam Streams were TW\;=\;0.000004TL^{3.2357}$ and TW\;=\;0.000002TL^{3.3566}$, respectively indicating the fish in Gam Stream became more rotund as length increases. The condition factor (K) and relative condition factor (Kn) against total length of Zacco temminckii at two streams indicated that the fish (>70 mm) in Cam Stream (mean K and Kn= 1.116, 1.21 respectively) had better nutritional condition than those in Buhang Stream (mean K and Ln = 1.046, 1.14 respectively). The results were corresponded with natural disturbances such as drought and intensive rainfall from 2001 to 2003 followed by human activities such as stream repair works. Therefore, it is considered to perform environmental impact assessment with not only confirmation of fish composition but also examination of ecological characteristics in population- level.