• Title, Summary, Keyword: Eurasian otter

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Eurasian Otter (Lutra lutra) Habitat Suitability Modeling Using GIS; A case study on Soraksan National Park

  • Park, Chong-Hwa;Joo, Wooyeong;Seo, Chang-Wan
    • Spatial Information Research
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    • v.10 no.4
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    • pp.501-513
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    • 2002
  • Eurasian otter (Lutra lutra) is one of endangered wildlife species whose population size is declining in Korea. To manage and conserve habitat for Eurasian otter, it is crucial to understand which habitat components affect otter habitat qualities. The objectives of this study were to develop a habitat suitability model of Eurasian otter in Soraksan National Park, to validate the model in Odaesan National Park. The research methods of this study were as follows. First, trace data and characters of Eurasian otter habitat were collected with Geographic Information System (GIS) data and Global Positioning System (GPS) receivers between 2000 and 2002. Second, the habitat use factors were identified as habitat characteristics of Eurasian otter and classified with habitat use and availability analyses. Third, significant factors of habitat model were extracted by Chi-square test. The last, Eurasian Otter Habitat Suitability Model (EOHSM) was employed by logistic regression method. Otter habitat use was positively associated with the reeds and shrubs areas adjacent to streams, the size of boulders, and low human disturbance in Soraksan National Park by EOHSM. This model had a classification accuracy of 74.4% at cutoff value of 0.5. Model validation showed a classification accuracy of 86.6 % at cut off value of 0.5 for otter habitat in Odaesan National Park.

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Impacts of Aquatic and Riparian Environmental Factors on Eurasian Otter (Lutra lutra) Presence Characteristics in the Nakdong River Basin (낙동강 권역의 하천 수면공간 및 수변환경이 수달의 출현에 미치는 영향분석)

  • Shin, Geehoon;Rho, Paikho
    • Journal of Environmental Science International
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    • v.26 no.12
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    • pp.1341-1353
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    • 2017
  • This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

Testing microsatellite loci and preliminary genetic study for Eurasian otter in South Korea

  • Jo, Yeong-Seok;Won, Chang-Man;Jung, Jongwoo
    • Journal of Species Research
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    • v.1 no.2
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    • pp.240-248
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    • 2012
  • We used a non-invasive technique with microsatellite primers to investigate genetic variation among Eurasian otters Lutra lutra in eastern South Korea. We collected twenty two otter spraints in January and six in August 2008. We used spraints from five dead otters from five different river systems for the present genetic analysis. We extracted DNA from 20 spraints from the January sample. Ten microsatellite primers (Lut435, Lut453, Lut457, Lut604, Lut615, Lut701, Lut715, Lut717, Lut733, and Lut832) for Eurasian otters were tested, and four loci were successfully amplified for further analyses. The results of genotyping the otter population with microsatellite loci lead to the identification of 9 individuals from the Ungokcheon Stream. The Ungokcheon population also showed a genetic structure represented by the Hardy-Weinberg equilibrium.

Selecting Core Areas for Conserving Riparian Habitat Using Habitat Suitability Assessment for Eurasian Otter (서식지 적합성 평가를 이용한 수변지역 핵심 보전지역 선정 - 수달을 대상으로 -)

  • Jeong, Seunggyu;Park, Chong Hwa;Woo, Donggul;Lee, Dong Kun;Seo, Changwan;Kim, Ho Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.2
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    • pp.19-32
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    • 2015
  • In Korea, significant riparian areas have been developed due to river maintenance projects. Introduction of new riparian facilities can negatively affect wildlife in the riparian areas. This study focuses on selecting core conservation areas for Eurasian Otter(Lutra lutra) to support decision making process for development of riparian areas. For the study, first of all, field data of study site were collected by field surveys. Secondly, stream naturalness was assessed to understand physical environments of the study sites. Thirdly, habitat suitability was assessed using occurrence data of Eurasian Otter and environmental data. Lastly, core areas for conservation was selected by comparing and synthesizing stream naturalness map and habitat suitability map. The selected core areas showed several characteristics. The number of artificial facilities is low in the core areas. Rocks which are preferred by Eurasian Otter to eat and excrete are plentiful in the core areas. Also, the ratio of adjacent farmland is high. Based on the analyses, it is expected that this study can contribute to decision making process for environmental spatial plans to better conserve habitats of Eurasian Otter.

Ectopic migration of Dirofilaria immitis in a Eurasian otter (Lutra lutra) in Korea

  • Jung, Ji-Youl;Lee, Kyunghyun;Seo, Hyun-Ji;Cho, Yun Sang;Kim, Young-Dae;Kim, Ji-Hyeon;So, ByungJae;Choi, Eun-Jin
    • Korean Journal of Veterinary Research
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    • v.58 no.2
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    • pp.107-109
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    • 2018
  • An 8-year-old female Eurasian otter (Lutra lutra) reared in a wetland center, died 2 h after sudden onset of astasia and dyspnea despite medical treatment. Gross examination of internal organs revealed 10 adult filarioid nematodes in the right ventricle of the heart and three between the left and right cerebral hemispheres. All nematodes were identified as Dirofilaria immitis by direct microscopy and polymerase chain reaction assay. Histopathological observation revealed multifocal hemorrhage in the cerebral subarachnoid space and focal necrosis with hemorrhage in the cerebellar parenchyma. Although rare, veterinarians should consider cerebral dirofilariasis as a differential diagnosis in unexplained neurological cases.

A study of Habitat Use Pattern of River Otters (Lutra lutra) with Land-cover Map (토지피복도를 활용한 수달의 서식지 이용에 관한 연구)

  • Lee, Sang-Don;Cho, Heesun
    • Journal of Environmental Impact Assessment
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    • v.14 no.6
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    • pp.377-385
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    • 2005
  • The Eurasian otter(Lutra lutra) is listed as No. 330 in natural monument. To manage and conserve habitat for otters, it is critical to understand which habitat components are important for otters. The objectives of this study were to analyze otter habitat characteristics in accordance with land-cover map. We investigated otter spraints and sprainting site in Geoje Island from January to December, 2004. with GPS coordinates. The analysis of otter habitat use pattern was used by Arcview ver. 3.2 with 1: 25,000 Topology Map and field data. Otter habitat use was strongly related to sites in riparian vegetation riparian(dam or river) structures. In this study, Gucheon was a site with high coverage of riparian vegetation and unconfined channels, thus recording higher number of spraint densities than those of Yeonchocheon. Yeonchocheon was under construction at lower stream areas so that otter habitat use was limited. This study suggests that securing suitable forests and riparian vegetation zone is essential for conservation of otters.

Distribution of Eurasian Otter Lutra lutra in Korea (한국 수달(Lutra lutra)의 분포 현황)

  • Jo Yeong-Seok;Won Chang-Man;Kim Joo-Pill
    • Korean Journal of Environmental Biology
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    • v.24 no.1
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    • pp.89-94
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    • 2006
  • This study was conducted to infer habitat distribution of Eurasian otter Lutra lutra in Korea. We recognized trace or presence of otter spraints from 254 of 750 pixels (pixel size: 13.75X11 km) used in this survey, amounting to 34%. The highest frequency of localities, with the spraints present, occurred in Gyeongsangbuk-do (49.62%) and the lowest one was observed in Gyeonggi-do (7.36%). The other regions were as follows: Gangwong-do (49.56%), Chungcheong buk-do (41.67%), Gyeongsangnam-do (38.00%), Jeolabuk-do (37.93%), Jeolanam-do (24.24%), Chungchengnam-do (20.29%). The counted number of the spraints was very low level in most of the localities where they were found (1.7spraints per sprainting site). It may indicate that small size of local populations would be expected in most of the localities. The habitat distribution of Korean otter, inferred from the distribution pattern of the spraints, will provide valuable basic information required for conserving and managing Korean otter.

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 수달(Lutra lutra Linnaeus, 1758)의 서식지 분석)

  • 정종철;조영석
    • Spatial Information Research
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    • v.12 no.1
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    • pp.29-42
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    • 2004
  • This Study was Analysis about Habitat of Eurasian otter Lutra lutra L. In October 2002 during September 2003, Otter Spraints and Sprainting site were searched in river Unkog of North-Kyongsang Province for taking the GPS coordinates. For Analysis of habitat, This data were used by Arcview ver. 3.2 with 1/25000 Topology Map and Other Field data. The result of Habitat Analysis meant that Habitat use was strongly related to Fish diversity and richness also vegetation and cover were connected with otter habitat. In other hand, The Human interferences including dense structures like House acted as factor of disturbance. This study suggest that The preceding about Suitable habitat having free of Human disturbance, abundant fish and good vegetation is essential In Trial for Conservation or Recovery of Otter like Trans-location.

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Surgical Implantation of Intra-abdominal Radiotransmitter and Observation of Postoperative Behaviour in the River Otter (Lutra lutra) of Korea (수달의 복강 내 무선추적 전파발신기의 이식과 수술 후 행동 관찰)

  • Kim, Young-Ki;Min, Hee-Kyu;Jin, Yeung-Bae;Lee, Sung-Kyu;Oh, Ki-Cheol;Kim, Jong-Kab;Lee, Scott-S.;Lee, Hee-Chun;Chang, Hong-Hee;Lee, Hyo-Jong;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
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    • v.26 no.4
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    • pp.395-399
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    • 2009
  • Radiotelemetry device was surgically implanted in the abdomen of a Eurasian river otter (Lutra lutra). Behaviors of the otter, hospitalized after surgical implantation were also observed. The surgical techniques involved an incision in the paralumbar fossa to introduce a radiotelemetry device into the abdominal cavity. Thirteen behaviors of the otter during hospitalization following abdominal surgery were observed and the time budget of each behavior and the times at which each behavior seems to appear most frequently were measured. This report could provide surgical techniques involving intra-abdominal implantation in otter and basic information associated with otter's behaviors during hospitalization.

Ecology of Otters and Utilization of Artificial Holts in the Ecosystem Conservation Region of the Seomjin River

  • Jo, Yeong-Seok;Choi, Byung-Jin;Won, Chang-Man;Kim, Joo-Pill
    • Korean Journal of Environmental Biology
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    • v.24 no.2
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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.