• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.75-84
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• 2022

Since South Korea did not adopt the recreation fishing using right (coupon) system, there were no recreation fishing statistics. This study selected 480 fishing vessels (10.4%) of a total of 4,611 fishing vessels (as of December 2019) as a survey sample using stratified sampling. Unlike other research institutes that conducted surveys related to the amount of tide on a one-time, this survey was conducted for five months (from May to October 2020, except the month of August). The captain investigated about types of fish, size, weight, etc. to anglers. A difference from previous studies was that about 7.0 million angler population (fishing more than three times a week) had 19.4 kg of catch per person for a year while other studies showed about 25.5-52.0 kg, respectively. The total fisheries resource catch amount was analyzed to be about 95,000 tons in this study and 116,000-166,000 tons in other studies. So there was a difference of about 1.2 to 1.8 times. This study aims to lay the foundation for the development of the fishing industry by preparing accurate statistical data and securing reliable basic statistics related to the fishing industry. Also, it could be usefully used as basic policy data such as introduction of a fishing using right (coupon) system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.946-953
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• 2022

Using the management strategy evaluation methods and data on the Korea chub mackerel Scomber japonicus where the state-space logistic production model is used as the operation and the estimation model respectivley, we examined the effects of both Dorn's rule, α and the buffer value for ABC (allowable biological catch), which are used by the Korea fishery managers for decision rules. We set scenarios that have different pairs of buffer and α values, which include those currently used in the management in Korea. Under each sceanario, we projected the fish population biomass until year 2050, during which ABC is determined in each year with the decision rule. We used three kinds of performance measures: (i) whether the biomass in 2050 is overfished; (ii) the average of annual yields over the simulation period; and (iii) the variability of annual yields over the period. We found that the current practice (buffer=0.9, and α = 0.05) resulted in the best performance in terms of avoiding the "overfished" status. However, the current practice failed to reach the maximum average of the annual yields and led to larger uncertainty in the annual yields.

• Fisheries and Aquatic Sciences
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• v.26 no.10
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• pp.617-627
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• 2023

Harvest control rules have been recently developed for some fisheries in Indonesia, including grouper fisheries, and are expected to reverse the trend of declining stocks. One of the proposed options of the harvest control rules is to implement the catch size limit. The catch size limit approach, however, is challenging, unless it is supported also with strong fisheries surveillance, law enforcement, and innovation. The catch size limit approach can be done by implementing changes in fishing methods and gear, including the application of different hook sizes in the hook and line fishing gear. This study examines the impact of different hook sizes on the length at first capture (Lc) and on the bell-shaped maximum selectivity using various selectivity models of the two targeted grouper species (Plectropomus leopardus and Plectropomus maculatus) in the Saleh bay, West Nusa Tenggara, Indonesia. We found that increasing hook size influences the grouper's catch size, increasing the Lc and the bell-shaped maximum selectivity of both species. Based on our findings, hook size can be used as one of the practical tools for grouper management measures, as part of harvest control rules to improve grouper stock in Indonesia.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.72-81
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• 2012

Using artificial neural network (ANN) technique, auction prices for common mackerel were forecasted with the daily total sale and auction price data at the Busan Cooperative Fish Market before introducing Total Allowable Catch (TAC) system, when catch data had no limit in Korea. Virtual input data produced from actual data were used to improve the accuracy of prediction and the suitable neural network was induced for the prediction. We tested 35 networks to be retained 10, and found good performance network with regression ratio of 0.904 and determination coefficient of 0.695. There were significant variations between training and verification errors in this network. Ideally, it should require more training cases to avoid over-learning, which leads to improve performance and makes the results more reliable. And the precision of prediction was improved when environmental factors including physical and biological variables were added. This network for prediction of price and catch was considered to be applicable for other fishes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.419-423
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• 2014

We consider changes in the fishing ground of the small yellow croaker Larimichthys polyactis and discuss their utility in predicting fishing conditions for this species. The fishing ground, which having been formed around Jeju Island since the 1970s, is dominated by the Yellow Sea Bottom Cold Water (YSBCW), and variation in its southward expansion from the Yellow Sea is the single most key environmental factor affecting the L. polyactis catch. When the YSBCW showed strong expansion and the fishing ground shifted to the west and southwest of Jeju Island, as occurred in the late 1980s, late 1990s, and early 2000s, the L. polyactis catch was low; conversely, when expansion was weak, as in the early 1990s and late 2000s, the L. polyactis catch was high. This relationship was statistically significant and should be useful in predicting fishing conditions for L. polyactis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.149-153
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• 1970

The present study deals with dynamical relationships between variations of common mackerel and horse mackerel catches in the waters adjacent to Korea for the years 1926 to 1969. The materials used here were obtained from Fishery Statistics published by the Bureau of Fisheries and the Fisheries Research and Development Agency of Korea, Secular variations of common mackerel and horse mackerel catches were classified intc five stages from A to E as shown in Fig. 2. As to variations of catch, the two species have alternating cycle trends occurring every ten years. With regard to the long period trend of catch, there is no correlation between annual variations of the species caught. Dynamical relationships between the two species showed a somewhat different pattern of catch as they transferred from one stage to another of the secular variations.

• Clinical and Experimental Pediatrics
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• v.57 no.9
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• pp.379-383
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• 2014

Recombinant growth hormone (GH) is an effective treatment for short children who are born small for gestational age (SGA). Short children born SGA who fail to demonstrate catch-up growth by 2-4 years of age are candidates for GH treatment initiated to achieve catch-up growth to a normal height in early childhood, maintain a normal height gain throughout childhood, and achieve an adult height within the normal target range. GH treatment at a dose of $35-70{\mu}g/kg/day$ should be considered for those with very marked growth retardation, as these patients require rapid catch-up growth. Factors associated with response to GH treatment during the initial 2-3 years of therapy include age and height standard deviation scores at the start of therapy, midparental height, and GH dose. Adverse events due to GH treatment are no more common in the SGA population than in other conditions treated with GH. Early surveillance in growth clinics is strongly recommended for children born SGA who have not caught up. Although high dose of up to 0.067 mg/kg/day are relatively safe for short children with growth failure, clinicians need to remain aware of long-term mortality and morbidity after GH treatment.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.223-233
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• 2006

The annual and spatial changes in the species composition of catch off Yeosu were analyzed using the daily sales slip catch data by a set net in the inshore waters off Dolsan Islands in Yeosu from April to October 2001, off Yeon Islands of Yeosu from April to October 2002 and in the offshore waters off Dolsan Islands of Yeosu from April to December 2003, respectively. Scomberomorus niphonius, Seriola spp., Trichiurus lepturus, Engraulis japonicus, Sarda orientalis, Todarodes pacificus, Pampus echinogaster, Sardinella zunasi, Scomber japonicus, Lophius litulon and Loligo beka were dominant species in abundance, indicating that pelagic fish were mainly caught by a set net off Yeosu. S. zunasi, P. echinogaster, Platycephalus indicus and L. beka inhabited mainly in the inshore waters, and S. niphonius, Seriola spp., T. lepturus, P. echinogaster, T. pacificus, Takifugu porphyreus and Pagrus major resided mainly in the offshore waters as the pelagic resident species. E. japonicus was a representative dominant species moving between the inshore and the offshore waters seasonally. S. zunasi and E. japonicus occurred in the inshore waters, and E. japonicus, L. litulon and Seriola spp. begain to be caught in the deep offshore waters in spring. Total catch was high during the summer season by migration of the open sea species such as T. lepturus, S. niphonius, S. japonicus, Seriola spp., S. orientalis, P. echinogaster and T. pacificus. In fall, S. niphonius, E. japonicus, Sphyraena pinguis, Siganus fuscescens and Leiognathus nuchalis were dominant in the inshore waters, and S. niphonius, P. echinogaster, Hyporhamphus sajori, S. japonicus and T. lepturus continued to occur from summer in the offshore waters but total catch decreased, indicating the typical seasonal variation pattern of the temperate region. Most of catchable fishes by a set net were the pelagic species showing a significant temporal variation. Collection and analysis of daily catch data by large set nets can be used to determine seasonal variation in species composition of pelagic fish in a study area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.44-53
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• 1989

In order to grasp the characteristics of a fishing ground at yeosu bay, the fluctuation in condition of the coast and that in catch by pound nets in the coast were investigated respectively. The results obtained are summarized as follows: 1. The water temperature in spring and summer was higher at the coast side than off shore, but in autumn and winter took the reverse. 2. The salinity was higher in spring and winter than in summer and autumn. A lower salinity zone was found at the Dolsan Do coast and higher ones were made off shore. 3. A eddy current was found at the Dolsan Do coast and a thermocline were made at the depth of 30 to 40 m in summer. But in autumn and winter the water became homogeneous. 4. The annual catch by the pound net was highest in 1984 and then decreased gradually. The monthly catch was highest in June and then decreased gradually. 5. The catches seemed to increase with the sea water temperature and salinity, and great catch was shown in 21$^{\circ}C$ to 27$^{\circ}C$ and 33.80% to 34.00%. 6. The component rate of fishes was 28.4% in spanish mackerel, 17.9% in anchovy, 19.5% in horse mackerel, 21.0% in sardine, 7.2% in hairtail, and 1% in common mackerel. 7. The fishes appeared continuously on way of fishing operation were spanish mackerel, hairtail, Yellow talil, crab, etc. An anchovy and sardine were caught mainly from March to July or August, horese mackerel and common mackerel from May to November. but puffer, swell fish, saury and filefish were caught mainly from April to October. 8. The sum of catch was largest in June, at which the wind direction was NE to SSW, the speed below 3.2m/sec, the atmospheric pressure below 1008mb, and precipitation beyond 154mm.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.330-340
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• 2010

This study was investigated the species composition of demersal fishes by a bottom trawler GAYA, in order to be used basic data for resources management of fishery in the jointly controlled waters of the East China sea. We caught 52 species, 1,167 individuals and 186.171kg in biomass in summer, and 1,924 individuals and 200.871kg in biomass in winter The first dominant species in individuals in summer was Glossanodon semifasciatus, and in biomass was Dentex tumifrons. But that in winter was Ovalipes punctatus in both individuals and biomass. It was a special phenomenon that crustacea was to be the first dominant species compared with general offshore fishery in Korea. Catch per unit effort (kg/hr) of bottom trawl in winter was higher than that in summer. There was also big difference by station in the diversity index, the evenness index and the dominant index.