• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.512-519
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• 1999

Seasonal variation in species composition and abundance of demersal fish in Yongil Bay were determined by analyzing samples collected using an otter trawl from January to October 1991. Of 59 species identified, Repomucenus lunatus, Tridentiger trigonocephalus, Repomucenus heguenini, Ammodytes personatus and Sillago japonica were dominated in abundance. Number of spiecies and biomass were low in winter and high in spring and summer. Species composition did not show spatial variation but showed seasonal variation. Number of spicies, abundance in number of individuals ($630 inds./10^3\;m^2$) and in biomass ($13,131g/10^3\;m^2$), and species diversity (2.00-2.54) of fish in Yongil Bay were higher than those of the coastal waters in the Yellow Sea or in the South Sea of Korea.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.591-596
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• 2012

Stream of Hongchon in Gangwon province was well known site for river otter(Lutra lutra) habitat. Because of habitat importance in this region a food analysis was conducted using 478 spraints of the species. A total food was domintnant by fish species occupying 80.5% and the dominant species was Zacco temminckii because of population abundance. Other food items were Amphibians and birds. Summer food was the highest due to its diversity. Gunup and Naechon streams were not different among diversity. Currently the highway construction was underway and we need more information regarding habitat requirement, and management implication for the species in this region.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.80-90
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• 2020

In order to understand the stress responses, we measured the concentration of stress hormones by using the fresh feces of wild otters in the Gwangju stream and Seomjin river during summer and winter in 2018. We compared seasonal and regional number of spraints (=otters' feces), temperature, altitude, water width, land cover, and water quality with stress hormones. The stress hormone levels were higher in summer than in winter, and significantly different to season and region. In addition, the number of feces were different according to the season and region, and showed a negative correlation with stress hormone. This study suggested assessing stress hormones as another promising method for the analysis of status of wild otters and it will contribute to establish the management and conservation policy, especially in urban area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.2
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• pp.71-77
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• 1994

A serious of study is carried out to practical use of the three-slot cambered otter board improved by the authors. As the first step, we designed main plates, slots and accessories, such as holding plate, fan-shaped towing plate, normans, center ring, etc. Standing on this design, we made the simple cambered and three-slot cambered model otter board with accessories in a linear scale 6:1. and carried out model test to examine the efficiency of these boards. The obtained results can be summarized as follows: 1. On the simple cambered board with accessories, the values of the maximum shear coefficient($C _{LX}$ ). drag coefficient(($C _{D}$) and hydrodynamic efficiency($C _{L}$/$C _{D}$ ) are 1.39, 0.56, 2.48 at $22^{\circ}$ of the angle of stall respectively. 2. On the three-slot cambered board with accessories, $C _{LX}$/$C _{D}$ and $C _{I}$/$C _{D}$ are 1.67, 0.92, 1.82 at $32^{\circ}$ of the angle of stall respectively. 3.$C _{LX}$ of board with accessories is smaller 10~12% than that of only the main plate, and the angle of stall is almost same. 4. $C _{LX}$ and the angle of stall of the three-slot cambered board with accessories are greater 20% and $10^{\circ}$ than that of the simple cambered board respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.43-57
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• 2002

This paper introduces an analysis method to predicting the flow characteristic of flow field around otter board In order to develope a high performance model. In this experiment, it is used a numerical analysis of flow field through CFD(Computational Fluid Dynamic), PIV method in which quantitative, qualitative evaluation is possible. In this experiment, it is used PIV method with flow filed image around otter board in order to analysis of flow characteristic. The result compared flow pattern with analysis result through CFD and also measurement result of lift and drag force coefficient carried out in CWC(Circulating Water Channel). The numerical analysis result is matched well with experiment result of PIV in the research and it is able to verify In the physical aspect. The result is as follows ; (1) It was carried out visibility experiment using laser light sheet, and picture analysis through PIV method in order to analysis fluid field of otter-board. As a result, the tendency of qualitative fluid movement only through the fluid particle's flow could be known. (2) Since PIV analysis result is quantitative, this can be seen in velocity vector distributions, instantaneous streamline contour, and average vorticity distributions through various post processing method. As a result, the change of flow field could be confirmed. (3) At angle of attack 24$^{\circ}$ where It Is shown maximum spreading force coefficient, the analysis result of CFD and PIV had very similar flow pattern. In both case, at the otter-board post edge a little boundary layer separation was seen, but, generally they had a good flow (4) As the result of post processing with velocity vector distributions, instantaneous streamline contour and average vorticity distributions by PIV, boundary layer separation phenomenon started to happen from angle of attack 24$^{\circ}$, and from over angle of attack 28$^{\circ}$, it happen at leading edge side with the width enlarged.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05a
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• pp.99-102
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• 2002

• Proceedings of the Zoological Society Korea Conference
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• 1999.04a
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• pp.49.2-49
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• 1999

No Abstract, See Full Text

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.160-165
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• 2006

The purpose of this study was to ascertain the prey composition and utilization of the Eurasian otter, Lutra lutra, in the ecosystem conservation region of the Seomjin River. The study was conducted for a 12-month period from March 2003 to February 2004 by spraints analysis and an investigation using artificial holts. We found seasonal variation in the number of spraints and composition of prey items. Fish were the main prey items throughout the period (82%), and other prey items included birds (14%), amphibians (2%) and arthropods (1%). In addition to prey identification, we investigated habitat utilization by otters through spraints distribution. The traces of otters were discovered in five of the six total artificial holts. However, the utilization of the artificial holts in the study area seemed to be limited as evidenced by the low frequency of traces in the holts.

• Journal of the Korean Society of Costume
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• v.22
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• pp.193-204
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• 1994

In this study the characteristics of Korean furs and peltry were discussed in the terms of usage and kinds from the literature survey of the relevant references, The following con-clusions were deduced. From Ancient to Koryo a kind of acient of Korea a lot of furs and peltry were produced and dressed. The leopad of Gochosun Korea was worthy of gold as an expensive goods to China. red dyed pelt of Silla Korea was traded with China and that pelt dyeing tech-nology of that pelt developed. The marten of Koryo was trade to Arabia and an otter skin to Kum Dynasty as loved goods. Korean furs and peltry made a reputation and were used for trading goods with China Japan and Arabia. Tratment technology in Korea became known to foreign country. There is another record that sheep and camels were offered to Koryo by around countries, And that Koryo employed men of Kum Dynasty as a shepherd. From ancient to Koryo Korea had had many kinds of furs of peltry as using goods such as leopard mart otter skin panther bear, manchurian wapili, fox, porpoise rat, mankey, horse, pig, wild bear, goat, cow, cat, dog, tiger, deer, raccoon dog and so on.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2006.11a
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• pp.89-89
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• 2006