• 한국수산과학회지
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• 제50권5호
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• pp.541-546
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• 2017

Feeding habits of dolphinfish Coryphaena hippurus, were analyzed. Fish samples were collected by using a purse seine, fishing and set net in the southern sea of Korea from January to December 2015. The size of C. hippurus ranged from 23.8 to 127.4 cm in fork length. The species with the highest percent index of relative importance (%IRI; the most important prey taxa) in the diets of C. hippurus were teleosts and cephalopod, including Engraulis japonicus, Thamnaconus modestus and Trachurus japonicus, Loligo edulis was the most frequently consumed cephalopods. Coryphaena hippurus also ate small amounts of amphipods and carid shrimp. The dietary compositions of C. hippurus was not significantly different among size classes or seasons (ANOSIM, P>0.05). As body size of C. hippurus increased the mean number of prey per stomach (mN/ST) tended to decrease, but the opposite trend was evident for mean weight of prey per stomach (mW/ST). The mN/ST and mW/ST also significantly varied with season (one-way ANOVA, P<0.05).

• Fisheries and Aquatic Sciences
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• 제22권12호
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• pp.29.1-29.7
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• 2019

Veterinary drugs are widely used to protect production-related diseases and promote the growth of farmed fish. The use of large amounts of veterinary drugs may have potential risk and cause adverse effects on both humans and the environment. In this study, we developed risk-based ranking based on a scoring system to be applied in the national residue program. In this approach, the following three factors of veterinary drugs that may occur as residues in fishery products were considered: potency (acceptable daily intake), usage (number of dose and withdrawal period), and residue occurrence. The overall ranking score was calculated using the following equation: potency × usage (sum of the number of sales and withdrawal period) × residue occurrence. The veterinary drugs that were assigned high score by applying this approach were enrofloxacin, amoxicillin, oxolinic acid, erythromycin, and trimethoprim. The risk-based approach for monitoring veterinary drugs can provide a reliable inspection priority in fishery products. The developed ranking system can be applied in web-based systems and residuemonitoring programs and to ensure safe management of fishery products in Korea.

• 한국수산과학회지
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• 제4권1호
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• pp.1-6
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• 1971

In order to study the catching efficiency of shrimp trawl equipped with electrodes around the net mouth and stimulant devices attached to the ground rope, an experimental operation was carried out at Oma-Island Shrimp Farm from October 3rd to November 5th, 1970. Many studies have been made on the shrimp trawl with electric stimulant devices, but few can be found for detailed scientific catching methods. Electric power consumption was so excessive that electric stimulant devices could not be developed for commercial purposes. As a first step toward the successive operations of the electric stimulant devices in the field, it is necessary to study fundamental principles, such as electric current, voltage, electric potential, potential difference, electric field and suitable pulse. The behaviour response of the common shrimp, Penaeus japonicus BATE to moving nets and electric stimulant devices were reported in the preceding papers based on the water tank experiments (Ko and Kim, 1970). Through comparative fishing tests the rate of catching efficiency during daylight time was confirmed to be from 89 to 96 per cent of the night catch efficiency, and with 30 V. 1.5 A. electric power was sufficent for practical sea operation.

• Fisheries and Aquatic Sciences
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• 제15권4호
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• pp.345-352
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• 2012

To predict catches of Pacific anchovy Engraulis japonicus larvae, anchovy eggs were collected in the coastal waters off Gunsan, Korea, in the Yellow Sea during the main spawning season (June to July) from 2003 to 2009. A ring net was repeatedly towed vertically at 10 stations during the daytime to sample eggs. Catch data estimated by auction sales were obtained from the Fisheries Cooperatives Union of Gunsan City and daily water temperature data in the outer harbor of Gunsan City during the survey periods were obtained from the National Oceanographic Research Institute. A significant relationship was found between anchovy egg density from June to July and larval catch from July to October in the same year. Catch of anchovy larvae in Gunsan were also high when optimal growth temperatures were recorded in the coastal waters off Gunsan in July. Although the recruitment success or failure of anchovy larvae can be predicted from variability in egg density, we suggest that mean daily water temperature is a more efficient indicator for predicting variability in catches of larval anchovy in the Yellow Sea.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.130-137
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• 2011

Visual stimuli of nets, which affect fishing selectivity, vary by twine diameter, color, and material under different light conditions and visual geometries. In this study, two cylindrical model codends of two mesh sizes, 28 and 43 mm, were made of high-contrast, dark brown polyethylene (PE) netting twine and low contrast, light-blue polyamid (PA) monofilament twine. Each model codend was filled with juvenile seabream and set in the water channel of a light-blue circular tank under a flow speed 0.8 m/s for 30 min. Light conditions were set to relatively bright, dim, and dark. The resulting retention rates of juvenile seabream were 15-35% lower for the low-contrast codend with PA monofilament than for the high contrast PE twine netting under bright and dim light conditions, while no difference was observed under dark conditions. The effects of mesh size and netting contrast on the retention rate were dependent on the light level, while the retention rate due to netting contrast was independent of mesh size. Therefore, low-contrast nets in the codend could help to reduce juvenile bycatch by disturbing the orderly optomotor response.

• 한국수산과학회지
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• 제46권6호
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• pp.801-806
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• 2013

Spiny lebbeid shrimp Lebbeus groenlandicus larvae were reared in the laboratory to estimate the energy budget from the zoeal to the post-larval stage. Energy expended by larvae on growth and respiration was determined from values for feeding, growth, molting, and metabolism. We calculated that 16.22 J were used for growth throughout all larval stages. Energy loss during molting was estimated as 1.03 J, and energy used for respiration was estimated as 1.31 J. Energy taken in by feeding was estimated as 77.16 J, while the sum of energies expended in excretion and egestion was 58.61 J. Larvae were estimated to assimilate 24.6% of ingested food as energy and to use ~85% of the assimilated energy for somatic growth. Gross growth efficiency ($K_1$) and net growth efficiency ($K_2$) were shown to be ~22% and 93%, respectively. Maintenance costs of respiration were estimated as ~9.7% of assimilated energy.

• 한국수산과학회지
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• 제46권6호
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• pp.807-812
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• 2013

The energy budget of the larvae of pandalid shrimp, Pandalopsis japonica, reared in the laboratory from zoea to post-larva was investigated. Energy used during the growth of the shrimp larvae was calculated daily for feeding, growth, molting, and metabolism. The total energy used was 16.2 J for the entire larval stage. Molting energy loss was estimated at a total 1.03 J. Energy used for respiration was estimated at a total of 1.85 J. The intake energy by feeding reached a total of 77.69 J. The total sum of energies used by excretion and egestion was 58.61 J. Larvae assimilated 24.57% of ingested food and used 84.91% for somatic growth. The gross growth efficiency ($K_1$) was 22.19% for the entire larval stage, and the net growth efficiency ($K_2$) was 90.31%. Maintenance costs were estimated at 9.69% of assimilated energy for the entire larval stage.

• 한국수산과학회지
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• 제20권5호
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• pp.381-390
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• 1987

본 연구는 1985년 5월부터 1986년 5월까지 삼천포 화력발전소를 대상으로 발전소 냉각계통의 가동이 식물플랑크톤의 기초생산력에 미치는 영향을 구명하기 위하여 실시되었다. 발전소 냉각계통이 총기초생산력에 미치는 영향은 평균 $7.5\~58.9\%(4.6\~12.1mgC/m^3/h)$이었으며, 순기초생산력의 경우는 이보다 높은 수준이 $58.7\~83.5\%(8.4\~11.9mgC/m^3/h)$. 영향요인 중 가장 큰 요소는 냉각계통 통과시 입는 기계적인 영향으로 그 범위가 $21.1\~110.7\%$에 달하였다. 삼천포 화력발전소 냉각계통에 이한 식물성탄소에 해당하는 량으로 추계되었다.

• 한국수산과학회지
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• 제10권1호
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• pp.49-52
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• 1977

1. 자리돔 들망에서 18과, 28속, 35종이 채집되었다. 낚이는 것과 저자망에 걸리는 것을 합하면 40종이상은 된다. 2. 어종으로서는 놀래기과 Labridae가 6종으로 가장 많았다. 3. 어획량으로서는 자리돔 Chromis natatus이 $90\%$이상이지만 줄도화돔 Apogon semilineatus과 놀래기류도 비교적 많이 어획되고 있다. 4. 자리돔 Chromis notatus은 수심 $15\~25m$ 수역에서 어획되고 있다. 5. 비식용의 관상용어종, 희귀종, 아열대성어류가 서기포연안일대에서 채집된다. 6. 다음 3종은 한국미기록종이다. Chromis analis, Franzia cheirospilos, Fugu exascurus.

• 한국수산과학회지
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• 제46권5호
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• pp.649-652
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• 2013

Distribution and migration of larval and juvenile sandfish Arctoscopus japonicus in the coastal waters off Gangwondo were determined monthly from samples collected by a rectangular bottom net in the coastal waters off Gangwondo from March to July, 2011. Fish were collected in abundance from the northern waters from March to June. The average total length (${\pm}SD$) was $11.5{\pm}1.6$ mm in March increased up to $53.5{\pm}3.3$ mm in June. The size distribution of sandfish by depth suggested that the fish grew waters less than 50 m deep until June, before moving deeper waters of around 100 m.