• Korean Journal of Environment and Ecology
• /
• v.25 no.2
• /
• pp.145-155
• /
• 2011

We surveyed diversity, distribution and diversity change of mammalian species in forests of the Nature Environment Research Park (Survey Area I; reservoir and surrounding forests, II; human habitat and surrounding forests and III; mountain forests) in Gangwon Province from 2004 to 2008. During our study, endangered species like Peromys volans, Lutra lutra and Prionailurus bengalensis were present in the surveyed areas. Diversity of mammalian species tends to be a little higher in the Survey Area I and III than the Survey Area II. Annual species diversity was a little higher in 2006, and then there was a little reduction from 2007. However, there was higher reduction in the number of individuals from 2007. Therefore, our results indicate that specific measures are needed for preservation of mammalian habitats to maintain the species diversity and the number of mammalian individuals.

• Journal of Wetlands Research
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2015

The bleaching phenomenon of otter spraints is indicates that the age of spraints (fresh or old spraints). As previous studies on the old otter faeces (spraint) have focused only on the external changes of spraints, it has been difficult to explain the difference of the decomposition rates among old spraints. We hypothesized that the micrometeorology difference caused by various characteristics of sprainting sites such as porosity and consistency of soil could affect the extent of the decomposition rate, the solar bleaching phenomenon of spraints used as a measure of the patterns of old spraints. Sprainting sites were classified into four types (Clay, Sand, Rock and Concrete spot) and each type was divided into two groups according to the sunlight condition (Sunny site and Shady site) to measure the effect of solar radiation. Micrometeorology of the sites were evaluated by measuring temperatures and humidities of the sites during the whole season. The variations in micrometeorology of the sunny sites according to the sprainting site types were examined with correlation analyses between the factors of micrometeorology. The analyses on the bleaching phenomenon of the spraints by micrometeorology showed that the highest rate of bleaching was found at the 'Rock spot' and 'Concrete spot' of the sunny site and especially in summer, the highest rate of bleaching ($63.4{\pm}7.6%$) was found at the 'Clay spot' of the sunny sites. The lowest rate of bleaching was found at the 'Sand spot' of the sunny sites. The above findings show that the difference in bleaching rates among sprainting sites was due to the seasonal or sunny condition. In addition, we found that the differences in thermal conductivity among sprainting site characteristics have resulted in different sprainting site temperature which have affected the rate of bleaching of spraints. In conclusion, this study suggests that studies of otters on their population size and home ranges using spraints as an indirect sign, should consider the effects of sprainting site characteristics and weather conditions.

• Journal of Environmental Impact Assessment
• /
• v.22 no.5
• /
• pp.525-528
• /
• 2013

River otter(Lutra lutra) are listed as endangered species and Natural monument in Korea, and this study examined the possibility of extinct of river otter in Hongchon river using with the application of Population Viability Analysis (PVA) technique. In Hongchon river areas population was estimated 9 individuals for the last 1999-2005 years and PVA analysis was done for the next 10 years using the average population of 9. Using the initial population the river otter was estimated 30% of extinct for the next 10 years. This estimation was quite low considering water pollution and construction of highways. Also PVA only used population size lacking in other life history information. Nonetheless river otter population can be in risk of extinction if the current construction of crossovers, cement bank are maintained. Long term information regarding life history needs essential.

• Journal of the korean veterinary medical association
• /
• v.46 no.3
• /
• pp.245-263
• /
• 2010

말 원충성척수뇌염(equine protozoal myeloencenphalitis; EPM)은 말에게 심각한 신경성 질병을 일으키는 원충성 질병으로서 Sarcocystis neurona가 원인체이다. 근육포자낭(sarcocyst)을 숨기고 있는 자연중간숙주를 포함한 S. nuerona의 완전한 생활사는 알려져 있지 않으나 주머니쥐의 일종인 opossum(Didelphis virginiana, Didelphis albiventris)이 최종 숙주이며, 말은 정상적 숙주로 알려져 있다. 왜냐하면 말에서는 분열체(schizonts)와 분열소체(merozoites)가 발견되기 때문이다. EPM 유사 질병들이 고양이, 밍크, 너구리, 스컹크, 태평양 점박이 바다표범, 포니, 바다수달 등을 포함한 다양한 포유류에서 발생한다. 고양이는 포자낭(sporocytes) 섭식 후 근육포자낭 단계를 숨기는 실험적인 중간숙주로서 역할을 할 수 있다. 최근 국내에서 신경증상을 나타내는 말에 대한 의심스러운 임상증상이 임상수의사들에 의해 관찰되어졌는, 정확한 진단을 하기위하여 S. nuerona에 의해 발생된 EPM의 역사, 구조, 생활사, 생물학, 병리론, 동물에서 질병 유도, 임상 증상, 진단, 병인론, 생태학, 치료 등에 대하여 알아보고자 한다.

• Journal of Environmental Impact Assessment
• /
• v.26 no.6
• /
• pp.508-523
• /
• 2017

This study monitored the changes before and after restoration of ecological stream focusing on the places which are applied Sustainable Structured wetland Biotop (SSB) system and ecological Fish-way for restoration of Maeno stream. A total of 11 species and 191 individuals of fishes were founded out which were not verified inhabitation before restoration at SSB wetlands. Especially, it was could identified that micro habitat and healthy Fish-way was created because the restored target species, Microphysogobio yaluensis and Iksookimia koreensis were identified that habitation was monitored in SSB wetland. Amphibian have been restored to a number of Rana nigromaculata found in and around wetlands at the time of the third survey, which is highly active after restoration. Specified endangered species class 1 and natural monuments designated by the Ministry of Environment, Lutra lutra lutra, as a Mammalian, uses the wetlands and ecological Fish-way as habitat areas, and the his habitat is restored. In the case of Flora, vascular plants emerging in the survey area were increased to 7 and 13 species before restoration and 15 and 19 species directly after restoration, and 22 species and 33 species after restoration. Vegetation after restoration was found to be a basic producer of various ecosystems and a plant community that contributes to the purification of water quality such as Phragmites japonica communities. As the result of water quality monitoring, the average of treatment efficiencies were BOD 64.3%, T-N 47.2%, T-P 80.7%. Successful treatment of the nonpoint pullution source, which is a limiting factor to disturb the ecosystem, creatively restored the target species in the water quality class I, II.

• Journal of Environmental Impact Assessment
• /
• v.14 no.6
• /
• pp.377-385
• /
• 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.

• Journal of Environmental Science International
• /
• v.26 no.4
• /
• pp.457-466
• /
• 2017

The extensive construction works of container terminals progressed since 2006 was converted to small scaled construction works or reclaiming works since 2012 in Busan New Port area. To investigate changes in activity of otters with the change of construction work scales, the linear densities of spraints at 15 localities of 5 areas (I-V) near the Busan New Port construction areas were surveyed during the period from 2012 to 2016. As the results, the average linear density of spraints has a tendency to increase since 2014. That is, the linear densities of spraints have increased at the area II and IV where the reclaiming works have been progressed, although have decreased or unchanged in the areas I, III and V where small scaled construction works have been progressed. Based on the fact that there were habitats at the Honamdo in the area II and the Yeondo in the area IV, otters seemed to restore their activities around the habitats as the center regardless of the reclaiming works.

• Korean Journal of Environmental Biology
• /
• v.23 no.3 s.59
• /
• pp.315-321
• /
• 2005

The population of river otter (Lutra lutra) has been declined most of the world due to hunting, habitat destruction and indirect or direct influences of eutrophication, acidification and toxic chemicals. This study is conducted to identify the population decline of river otter in Korea with relation to environmental pollution caused by accumulation of heavy and flared metals. The field survey was conducted during Jan~Dec, 2004 at a monthly basis by collecting spraints. A total of 228 spraints were collected and analysis was done by ICP-AES. The concentrations of fourteen metals (Cr, Zn, Cd, Pb, Ni, Fe, Co, Mn, Mg, Cu, Al, Ba Hg, As) have been determined. Annual concentrations of Cd $(1.38{\mu}g\;g^{-1}),\;Zn\;(599.06\;{\mu}g\;g^{-1}),\;Pb\;(5.54\;{\mu}g\;g^{-1})$ at Gucheon were higher than those of Yeonchocheon. Concentrations of $Cr\;(5.01{\mu}g\;g^{-1}),\;Ni\;(1.91{\mu}g\;g^{-1}),\;Co\;(0.25{\mu}g\;g^{-1})$ were higher at Yeonchocheon. Most metals in winter were significantly increased (P<0.05) as season progressed from spring to winter. $Pb\;(15.58{\mu}g\;g^{-1}),\;Cu\;(15.15{\mu}g\;g^{-1}),\;a;Guchoen\;and\;Cr\;(5.77{\mu}g\;g^{-1})$ at Yeonchocheon were high in the downstream of winter.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.10
• /
• pp.55-63
• /
• 2007

Multicast is an efficient transport mechanism for community communications and MANET is recently regarded as a promising solution for support ubiquitous computing as an underlying network technology. However, it is hard to deploy multicast mechanism into MANET owing to scarce resources in wireless networks and unpredictable changes in network topology. Several multicast mechanisms have been proposed in the literature to overcome the limitations. Especially, overlay multicasting schemes present several advantages over network based multicasting schemes. Yet, the overlay multicasting schemes still introduce redundant data transmissions that waste network bandwidth and battery of relay nodes. As a result the performance of the network is degraded. To reduce the redundancy, we propose an efficient way to construct an overlay structure as a multicast data delivery tree that utilizes a branch node which belongs to the tree. By using network simulation, we show that the proposed scheme presents higher packet delivery ratio and lower transmission cost than previously proposed schemes.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.18 no.2
• /
• pp.19-32
• /
• 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.