• 수산해양기술연구
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• 제19권1호
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• pp.1-11
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• 1983

한국 토로올어선들이 아프리카 사하라 연안어장에 출어하여, 1975년 5월부터 1976년 4월까지, 이 해역의 중심어장으로 알려진 22$^{\circ}$00'~25$^{\circ}$30'N의 연안에서, 연 16,725척이 252,609회 예망하여, 살오징어 3,754,786kg, 대형갑오징어(체중 300g 이상) 7,540,532kg 소형갑오징어(체중 300g 미만) 9,539,570kg, 문어 11,130,462kg, 서대 2,010,540kg, 돔류 2,360,970kg, 기타 어종 15,951,250kg을 어획하였다. 이들이 어획된 해역을 경위도 30분간의 소해구로 분할하고, 이 소해구별 월평균 예망당 어획량을 구하고 그로부터 어종별 어획량 분포를 고찰한 결과를 요약하면 다음과 같다. 1) 어종별 예망당 어획량을 비교하면, 살오징어 14.9kg,, 소형갑오징어 대형갑오징어 37.8kg, 문어 44.1kg, 서대 8kg, 돔류 9.3kg 기타어종 63.1kg의 비율로 혼획한 결과를 요약하면 다음과 같다. 2) 살오징어는 23$^{\circ}$00'N 이남과 24$^{\circ}$30'N 이북의 해역에서 많이 어획되었고, 주어기는 8~11월이었다. 3) 갑오징어는 대형은 23$^{\circ}$00'~25$^{\circ}$00'N의 해역에서 많이 어획되었고, 주어기는 12~5월이었으며, 소형은 23$^{\circ}$30'~25$^{\circ}$00'N의 해역에서 많이 어획되었고, 주어기는 4~6월과 11~1월이었다. 4) 문어는 23$^{\circ}$00~25$^{\circ}$00'N의 해역에서 많이 어획되었고, 주어기는 3~4월과 9~1월이었다. 5) 서대는 23$^{\circ}$00'N 이남과 25$^{\circ}$00'N 이북의 해역에서 많이 어획되었고, 주어기는 6~11월이었다. 6) 돔류는 23$^{\circ}$30'N 이남과 25$^{\circ}$00'N 이북의 해역에서 많이 어획되었고, 주어기는 5~11월이었다. 7) 기타어종은 23$^{\circ}$30'N 이남과 25$^{\circ}$00'N 이북의 해역에서 많이 어획되었고, 주어기는 5~10월이었다

• Journal of Nutrition and Health
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• 제22권3호
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• pp.149-158
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• 1989

To investigate the nutritional quality of packaged meals produced by packaged meal manufactures, a nutritional evaluation was conduced. Samples examined in this study were 95 Products which composed of 86 Doraks, 7 Kimplabs and 2 Yubuchopabs Produced in packaged meal manufactures in Seoul City and Kungki-do province The distribution of food groups showed that amounts of animal foods were abound, but amounts of green vegetables, limited in Dosirak comparing to one meal RDA levels. Amounts of meats, fishes and shells are increased more than amounts of egged and legumina with increase of price of Dosirak. The total kinds of food and the amounts of certain food in Kimpab and Yubuchopab were lower than Dosirak. The energy and protein contents of Dosirak were found to be higher than one meal RDA levels, with exception of protein content in Dosirak of the price 1000 won. The contents of energy and protein in Kimpab and Yubuchopab are less than one meal RDA levels. Calcium and iron contents in Dosirak, and calcium content in Yubuchopab were present in excess compared to the one meal RDA. However, In Kimpab, calcium and iron contents were lower than the one meal RDA. On the whole, vitamin contents of Dosirak were sufficient whereas vitamin contents of Kimpab and Yubuchopab were lower than the one meal RDA. Number of side dishes used in Dosirak were 6-23 items depending on prices. Guidelines were suggested for effective nutritional quality control of packaged meals.

• 한국지구과학회지
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• 제39권1호
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• pp.67-88
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• 2018

The important PH (paleontological heritages) with scientific, educational and esthetic values designated as natural monuments and protected by legislations of South and North Koreas are herein compared for the first time. On the basis of data (Jan. 2017) provided by the Cultural Heritage Administration of (South) Korea, a total of 457 natural monuments was designated. Of these, geological heritages are 80 in number, which includes 24 (30%) PH. Data (Dec. 2005) of North Korea show that a total of 474 natural monuments was designated. Among these, geological and geographical ones are 154 in number, which includes 22 (14%) PH. Differences between PH of South and North Koreas are regarded to be directly related with geological difference in distribution of the fossil-bearing strata between South and North Koreas. PH of Silurian corals, Devonian plants, Jurassic fishes, Cretaceous dinosaur tracks, birds (so called Korean Archaeopteryx) and pterosaurs, and Pleistocene paleoanthropological fossils appear to be scientifically significant. Together with these North Korean PH, scientific, esthetic, conservational, educational, and economical values of important PH including KCDC (Korean Cretaceous Dinosaur Coast), Jigunsan Shale, and Geumgwangdong Shale of South Korea should be evaluated as potential future candidates for international heritages.

• Fisheries and Aquatic Sciences
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• 제26권4호
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• pp.256-267
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• 2023

The suitability of any fish species for successful aquaculture requires basic information on its reproduction and growth. This study investigated some facets of the reproductive biology of Synodontis shall (Mochokidae) from River Siluko in Nigeria. Fish samples were collected forth-nightly for a duration of fourteen (14) months-March 2015 to April, 2016 with the assistance of artisanal fishermen. Fishes were identified using taxonomic guides and standard techniques were used for determination of sex ratio, gonad maturation and fecundity. Linear regression method was used to define the correlation between fecundity and fish length, body weight and ovary weight. Results showed that sex ratio did not indicate a significant divergence (p > 0.05) from the 1 male to 1 female distribution ratio (1:1.41). Gonad morphology revealed paired gonads. Testes and ovaries were classified into four maturity stages: immature, resting, ripening and ripe. Gonadosomatic index ranged from 0.04 to 5.68 (males) and 0.03 to 20.19 (females). Absolute fecundity ranged from 1,014 to 4,520 eggs (mean = 2,592 eggs) and did not correlate significantly (p > 0.05) to ovary weight. This study has contributed to existing data on the biology of freshwater fish species in Nigeria and provided valuable information for fishery management tools in the conservation and utilization of this valuable freshwater fish species.

• 한국수산과학회지
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• 제28권6호
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• pp.699-707
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• 1995

Eurasian yellow perch (Perca fluviatilis) and American yellow perch (Perca flavescens) are known to be endemic species in Eurasia and North America, respectively. The presence of endemic species on each continent suggests their independent evolutionary history. However, because of the morphological similarity, distribution pattern, and only recent fossil record, their divergence time and speciation of the two Perca species has long been controversial. Here, from the comparison of the entire nucleotide sequences of cytochrome b gene, large genetic divergence between the two Perca species is observed although they are morphologically similar each other. Among 1,140 base pairs, interspecific nucleotide differences are found at 130 sites $(11.4\%)$. The differences varies with codon position, showing 22 sites in the first, 5 sites in the second, and 103 sites in the third codon position. Considering the types of nucleotide changes, transitional differences are much more than transversional differences and its ratio turned out to be 5.19. The estimated divergence time of the two Perca species indicates that they were separated each other approximately in the late Miocene period, which implies the long history of speciation. With comparison of the inferred amino acid sequences, strong structural and functional constraints which seem to be maintained by the highly conservative amino acid residues or protein regions, as found in other taxonomic groups of organisms, are also recognized in the cytochrome b of the fishes examined.

• 한국환경보건학회지
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• 제44권6호
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• pp.581-590
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• 2018

Objectives: We aimed to investigate the species composition of fish and benthic macroinvertebrates in the Namgang Dam reservoir and assess the reservoir's ecological quality. Methods: Fish and benthic macroinvertebrates were seasonally sampled around the Namgang Dam reservoir from October 2013 to September 2014. Results: A total of 970 fish specimens were collected for this survey, including 4 orders, 14 families, and 25 species. Fourteen endemic species were observed, including Coreoleuciscus splendidus. The most observed among the endemic species caught was Zacco koreanus (14.4%). A total of 9,093 benthic macroinvertebrates, including 51 families and 92 species, were also found. The predominant species in the study area was Chironomidae sp. 1. Diplonychus esakii, whose habitat is distribution-specific as designated by the Korean National Institute of Environmental Research (NIER), were also observed. A total of 386 specimens were collected of the invasive alien species Lepomis macrochirus, and the percentage of Lepomis macrochirus and Micropterus salmoides made up 42.0% of all specimens collected in the area. Conclusion: The mean ecological score of the benthic macroinvertebrate community (ESB) ranged between 24 and 40, which indicates that the environmental condition of the target sites is somewhat poor. Based on the results of this research, building habitats for benthic macroinvertebrates should be considered, and extermination plans for invasive alien fish species should be prepared.

• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.33-41
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• 2021

This study was carried out to observe the development of the autonomous skeletal development of the Favonigobius gymnauchen. Total length (TL) of larvae 3 days after hatching (DAH) were mean TL of 3.34 mm, with a line-shaped parasphenoid ossification in the cranium and basioccipital ossification in the back. The 10 DAH larvae had a mean TL of 5.20 mm, with the number of caudal vertebrae increasing to 15. The urostyle and two hypural bones in the lower part also began to ossify. The 23 DAH juveniles had a mean TL of 8.47 mm. The pectoral girdle's skeleton was completed as the scapula and coracoid were ossified. The pelvic girdle also fully supported the ventral fin as its ossification was completed. Favonigobius gymnauchen and Tridentiger obscurus showed similar characteristics in terms of the anus location of hatched larvae, number of myotomes, and melanophore distribution during the morphological development of the larvae and juveniles. However, this study confirmed differences in the development of the vertebrae and urostyle bone.

• 수산해양기술연구
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• 제47권2호
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• pp.146-152
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• 2011

Underwater CCTV camera systems are increasingly replaced the traditional net approach of assessing the species, numbers and aggregation patterns of marine animals distributing around the artificial reefs installed in the inshore fishing grounds, in particular, in relation to the biological investigation of behavior and distribution patterns of target fishes. In relation to these needs, we developed a multi-directional underwater CCTV camera system to use in detecting and tracking marine animals in the artificial reef ground. The marine targets to be investigated were independently tracked by using a camera module toward the bottom and four camera modules installed in the interval of $90^{\circ}$ in horizontal plane and inclination of $45^{\circ}$ in vertical plane of the CCTV system without the overlap of video frames by each camera module. From the results of several field tests at sea, we believe that the developed multi-directional underwater CCTV camera system will contribute to a better understanding in evaluating the effect of artificial reefs installed in the inshore fishing grounds.

• 수산해양기술연구
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• 제35권4호
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• pp.404-409
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• 1999

The in situ target strengths of, maurolicus muelleri were measured by the split beam echo sounder system at the frequency of 38kHz.Target strengths were measured during the night time in order to obtain the pure separated echoes from the scattered individual. And also it was to establish reasonable threshold due to taking the signals like as the planktons and etc.Since Maurolicus muelleri is a typical micronektonic fish, they mainly consisted of deep scattering layers(DSLs), and had a vertical migration perrodically during daytime and at night.We found that the Maurolicus muelleri occupied about 99% of total catch. Total length ranged from 4.5 to 5.7cm with a mean of 5.2cm and a standard deviation of 0.22cm.The target strengths of Maurolicus muelleir ranged from -60.4 to - 52.7dB and -59.2 to - 52.5 dB in the water layer of 10~30m and 30~50m depth, perspectively. Mean target strength was -57.1dB/fish and -28.5dB/kg. The target strength had the relation with the total length of the fish as, TS=20logL-71.4.

• 수산해양기술연구
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• 제55권1호
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• pp.39-49
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• 2019

Acoustics are increasingly regarded as a remote-sensing tool that provides the basis for classifying and mapping ocean resources including seabed classification. It has long been understood that details about the character of the seabed (roughness, sediment type, grain-size distribution, porosity, and material density) are embedded in the acoustical echoes from the seabed. This study developed a sophisticated yet easy-to-use technique to discriminate seabed characteristics using a split beam echosounder. Acoustic survey was conducted in Tongyeong waters, South Korea in June 2018, and the verification of acoustic seabed classification was made by the Van Veen grab sampler. The acoustic scattering signals extracted the seabed hardness and roughness components as well as various seabed features. The seabed features were selected using the principal component analysis, and the seabed classification was performed by the K-means clustering. As a result, three seabed types such as sand, mud, and shell were discriminated. This preliminary study presented feasible application of a sounder to classify the seabed substrates. It can be further developed for characterizing marine habitats on a variety of spatial scales and studying the ecological characteristic of fishes near the habitats.