• Title/Summary/Keyword: Otter

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A study on the bottom trawl gear by the trial of a stern trawler-I -On the Resistance of bottom trawl gear- (실선 시험에 의한 저층 트롤 어구에 관한 연구-I -어구의 저항에 관하여-)

  • 조봉곤;조성옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.4
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    • pp.274-280
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    • 2000
  • To analyze the resistance of the bottom trawl which is composed with 6 seams net, the field experiment was carried out on the sea near Kokunsan Is., western sea of Korea. The resistance was respectively measured in the otter board and the net according to the change of warp length and towing speed. The results obtained are summarized as follows : 1. Total resistance of the test trawl gear are slightly increased according to the length of warp. 2. The resistance of net is increasing a little according to the length of warp, but it is expressed. $$ R_n/=10 \frac{d}{\ell}$representatively. 3. The resistance of otter board can be expressed $Rb=1810_{\upsilon}^0.8.$ 4. Comparing with the value of measuring resistance and Koyama formula resistance by the length of warp respectively, the resistance of test trawl gear is high in the slow towing speed, and the resistance of Koyama formula is high in the fast towing speed, and that the cross-point of the both line between the resistance of the test net and Koyama formula is moved to high according to the increment of warp length.

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Seasonal Variation in Species Composition of Fish in Suyoung Bay, Korea (수영만에 분포하는 어류의 종조성과 계절변동)

  • KIM Yeong Hye;JEON Bok Soon;KANG Yong Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.4
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    • pp.320-324
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    • 2000
  • Fish were collected by an otter trawl from December 1995 to July 1997 in Suyoung Bay, Korea. The temperature ranged from $12.0 to 27.7^{\circ}C$ and salinity ranged from $31.2 to 34.45{\%}_{\circ}$, The number of species, number of individuals and biomass of fish collected were 52 species, 2,006 individuals and 63,580 grams, respectively. The demersal fish predominated in the number of individuals ($90.4{\%}$) and biomass ($81.4{\%}$). The diversity index (H') was $1.5{\~}2.6$, The dominant species were Platycephalus indicus, Limanda yokohamae, Siliago sihama and Hexagrammos otakii.

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Species Composition and Seasonal Variation of Fish Assemblage in the Coastal Water off Gadeok-do, Korea -1. fishes Collected by a Small Otter Trawl- (가덕도 주변 해역 어류의 종조성과 계절 변동 -1. 소형 기선저인망에 의해 채집된 어류-)

  • HUH Sung-Hoi;AN Yong-Rock
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.4
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    • pp.288-301
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    • 2000
  • The species composition and seasonal variation of fish assemblage in the coastal water off Gadeok-do, Korea were studied using the monthly trawled samlpes through a year of 1998. During the study period, 110 species of fishes from 57 families were collected. Repomucenus valenciennei, Thryssa kammalensis, Leiognathus nuchalis and Zoarces gilli dominated the fish assemblage throughout the year, and were responsible for $ 57.6{\%}$ and $37.2{\%}$ in the number of individuals and biomass, respectively. Fish species of secondary importance in abundance were Sillago japonica, Apogon lineatus, Pholis fangi, Engraulis japonicus, Thryssa adelae, Pho;is nebulosa, Conger myriaster, Liparis tanakai, Acentrogobius pflaumii, Limanda yokohamae, Chaeturichthys hexanema, Erisphex pottii and Cunoglossus abbreviatus. Higher numbers of species were collected in spring and autumn than in summer and winter. Abundance was high in spring and autumn, and low in summer and winter, Species diversity indices showed that the fish assemblage was more diverse in autumn than any other seasons.

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A Phylogenetic Analysis of Otters (Lutra lutra) Inhabiting in the Gyeongnam Area Using D-Loop Sequence of mtDNA and Microsatellite Markers (경남지역 수달(Lutra lutra)의 mitochondrial DNA D-loop지역과 microsatellite marker를 이용한 계통유전학적 유연관계 분석)

  • Park, Moon-Sung;Lim, Hyun-Tae;Oh, Ki-Cheol;Moon, Young-Rok;Kim, Jong-Gap;Jeon, Jin-Tae
    • Journal of Life Science
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    • v.21 no.3
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    • pp.385-392
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    • 2011
  • The otter (Lutra lutra) in Korea is classified as a first grade endangered species and is managed under state control. We performed a phylogenetic analysis of the otter that inhabits the Changnyeong, Jinju, and Geoje areas in Gyeongsangnamdo, Korea using mtDNA and microsatellite (MS) markers. As a result of the analysis using the 676-bp D-loop sequence of mtDNA, six haplotypes were estimated from five single nucleotide polymorphisms. The genetic distance between the Jinju and Geoje areas was greater than distances within the areas, and the distance between Jinju and Geoje was especially clear. From the phylogenetic tree estimated using the Bayesian Markov chain Monte Carlo analysis by the MrBays program, two subgroups, one containing samples from Jinju and the other containing samples from the Changnyeong and Geoje areas were clearly identified. The result of a parsimonious median-joining network analysis also showed two clear subgroups, supporting the result of the phylogenetic analysis. On the other hand, in the consensus tree estimated using the genetic distances estimated from the genotypes of 13 MS markers, there were clear two subgroups, one containing samples from the Jinju, Geoje and Changnyeong areas and the other containing samples from only the Jinju area. The samples were not identically classified into each subgroup defined by mtDNA and MS markers. It could be inferred that the differential classification of samples by the two different marker systems was because of the different characteristics of the marker systems used, that is, the mtDNA was for detecting maternal lineage and the MS markers were for estimating autosomal genetic distances. Nonetheless, the results from the two marker systems showed that there has been a progressive genetic fixation according to the habitats of the otters. Further analyses using not only newly developed MS markers that will possess more analytical power but also the whole mtDNA are needed. Expansion of the phylogenetic analysis using otter samples collected from the major habitats in Korea should be helpful in scientifically and efficiently maintaining and preserving them.

Analysis about Habitat of Eurasian Otter Lutra lutra L. by Using GIS in the River Ungok of North-Kyongsang Province (GIS를 이용한 경북 봉화군 운곡천 수달의 서식지 분석)

  • Jeong, Jong-Chul;Jo, Yeong-Seok
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.05a
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    • pp.175-179
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    • 2005
  • 본 연구는 2002년 10월부터 2003년 9월까지 경상북도 봉화군 운곡천을 대상으로 수달의 배설물 및 배설지 등의 흔적조사를 통해 얻은 GPS좌표를 중심으로 하여 수치지도 및 현장조사에서 얻은 정보를 Arc/view를 이용해 수달의 최적 서식지분석에 이용하였다. 분석결과 수달의 서식지 이용에는 먹이자원인 어류의 종다양도와 풍부도가 깊은 연관을 맺고 있으며 식생 등의 서식환경이 밀접한 연관을 맺고 있음을 확인하였다 또한, 밀집된 주거지 등 인간의 간섭은 수달의 서식지 이용에 교란요인으로 작용한다는 것을 알 수 있었다. 본 연구는 수달의 보전 및 관리를 위한 적합 서식지를 선정하기 위해 GIS기법의 활용에 대한 적용 가능성을 평가하였다.

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On the Deck Wetness Through Slipway of a Stern Trawler in Wind and Waves (풍.파랑중에서 투망중인 트롤어선의 슬립웨이를 통한 갑판침수에 관한 연구)

  • 손경호
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.6 no.1
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    • pp.35-45
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    • 2000
  • The slipway, which is one of stern construction, is necessary for stern trawler to let fishing implements, such as fishing net, otter board and warp, go out effectively. It may be doubtable whether there is any possibility for deckwetness to occur because the slipway is obliquely in contact with sea surface. The author discusses any possibility for deckwetness through slipway of stern trawler in wind and waves. A 350 G/T class, ocean-going stern trawler is adopted for the present study. The stem trawler is particularly assumed to drift with fishing implements hung down the slipway due to internal or external accident during fishing operation in real sea. The author considers two factors as possibility for deckwetness to occur through slipway. One is mooring effect of fishing implements hung down the slipway under wind pressure, and the other is relative ship motion in vertical direction in waves. Through the numerical calculation, the author clarifies that there is thin possibility for deckwetness to occur from above two points of view.

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Fauna of Fish Collected by Otter Trawl at Coast off the Southeast Area of Geoje Island (저인망에 채집된 거제도 남동지역 해약의 어류상)

  • 윤창호;심재환
    • Korean Journal of Environment and Ecology
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    • v.14 no.3
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    • pp.167-174
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    • 2000
  • 거제도 남동 해안지역의 한려해상국립공원 보호구역에서 해상자원의 보존을 위한 기초자료를 확보하고자 거제도 일운면 예구리, 남부면 다대리 및 남부면 저구리 해얀지역에서 1999년 6월부터 2000년 3월까지 어류상 조사를 실시하였다. 조사를 통하여 확인된 어류는 총 16목 47목 69속 85 종 2, 789개체가 채집되었으며, 45종이 출현한 농어목(Perciformes), 10종씩 출현한 가자미목 (Pleuronectiformes) 및 횟대목(Scorpaseniformes)의대부분 저서생활을 하는 어류가 주로 채집되었다. 전체 조사기간 동안 가장 만하은 개체가수가 채집된 어류를 줄비늘치(Coelorhyncus multispinulosus) 458개체(16.4%)로 확인되었고 칠서대(Cynoglossus interruptus) 384개채(13.8%), 노랑촉수(Upeneus bensasi) 285개체(10.2%) 등의 순 이었다. 조사시간 6월에 가장 다양하고 풍부한 어류가 채집되었다.

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A new record of the Axiid shrimp Balssaxius habereri (Balss, 1913) (Crustacea: Decapoda: Axiidea) in Korean waters

  • Kim, Jung Nyun;Choi, Jung Hwa;Im, Yang Jae;Jo, Hyun-su
    • Fisheries and Aquatic Sciences
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    • v.19 no.9
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    • pp.36.1-36.3
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    • 2016
  • Balssaxius habereri (Balss, 1903) has been newly reported in Korean waters. This species was previously known from the Pacific coast of northern Japan, Korea Strait, Yellow Sea, and Japanese coast of the East Sea. Specimens were collected from western Jeju Island using otter trawls at depths of 65-85 m. Regarding Korean axiid shrimps, a single species, Boasaxius princeps (Boas, 1880), previously known as Axiopsis princeps in Korea, has been recorded. B. habereri is easily distinguished from B. princeps as it does not have tufts of setae on its body and males do not have the first pleopod. Morphological descriptions and color photos of the specimens are provided.

Ultrastructural Study of Tentacular Pigment Cells in the Chinese Mystery Snail, Cipangopazudina chinensis mazleata Reeve (논우렁이(Cipangopaludina chinensis malleuta Reeve) 촉수 색소세후의 징세횡조에 관한 연구)

  • 송용직;문영진김우갑김창환
    • The Korean Journal of Zoology
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    • v.30 no.3
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    • pp.292-300
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    • 1987
  • The ultrastructure of the tentacular pigment cells and the origin of the pigment granules in the Chinese mystery snail, Cipangopaludina chinensis malleata Reeve, are studied with electron microscope. Tentacular pigment cells of the Enail are the melanophores which contain electron dense melanosomes(melanin pigment granules) . Melanophores are distributed among the connective tissues but otter kind of dermal chromatephores are not observed. The epidermal melanin units are observed in the epithelial tissues of the tentacles. Among the several kinds of epithelial cells, only the epithelial supporting cells contain these pigment granules. Synthesis of the pigment materials is from the rough ER and pigment granules are finally being packaged and released by the Golgi complexes but limiting membrane of these granules are presumed to be originated from the smooth ER.

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A Study on Emperor s Costumes during the Reign of Chien-lung in Ching Dynasty (淸代 乾隆朝 『穿戴 案』 服飾硏究)

  • 최경순
    • The Research Journal of the Costume Culture
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    • v.4 no.2
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    • pp.207-217
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    • 1996
  • The founding of ching costume system starts from the rule issued in second year of Te-chong reign that the clothing of Manchu people is prohibited to be chinesized. It has undergone many revisions and is officially established in the 37th year of Chien-lung reign. This study is Emperor's costumes during the year in Chien-lung reign. The results are as follows: Emperor's costumes go to the travel are Chi-fu hat and Hsing-fu. Sea-dragon hat changes on otter skin or beaver hat and Ching-rong and ching-ni hat changes velvet hat. Light green informal wear is to be worn once a year. Name of sacrificial robes does not exist in Ching-hui-dien-tu but it take the place of Chao-fu I and Chao-dai II in Chuan-dai-dang-an. Sacrificial robes wear with indigo boots and the other cases wear blue boots and shoes and socks. The shape on ornaments in belt of sacrificial robes is tetragon style.

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