• Title/Summary/Keyword: Islands

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Relationships between Fish Communities and Environmental Variables in Islands, South Korea

  • Kwon, Yong-Su;Shin, Man-Seok;Yoon, Hee-Nam
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.2
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    • pp.84-96
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    • 2022
  • Most of the islands of Korea are distributed in the South and West Sea, and it consists of independent small stream. As a result, the fish community that inhabits the island's stream is isolated from the mainland and other island. This study utilized a Self-Organizing Map (SOM) and a random forest model to analyze the relationship between environmental variables and fish communities inhabiting islands in South Korea. Through the SOM analysis, the fish communities were divided into three clusters, and there were differences in biotic and abiotic factors between these groups. Cluster I consisted of sites with relatively larger island areas and a higher number of species and population. It was found that 15 out of 16 indicator species were included. Meanwhile, the remaining clusters had fewer species and populations. Cluster II, especially, showed the lowest impact from physical variables such as water width and depth. As a result of predicting the species richness using the random forest model, physical variables in habitats, such as stream width and water depth, had a relatively higher importance on species richness. On the other hand, forest area was the most important variables for predicting Shannon diversity, followed by maximum water depth, and gravel. The results suggest that this study can be used as basic data for establishing a stream ecosystem management strategy in terms of conservation and protection of biological resources in streams of islands.

Status analysis of patients on islands and seas of Jeollanam-do (전라남도 섬과 해상에서 발생한 환자의 현황분석)

  • Choi, Young-Ju;Yun, Jong-Geun
    • The Korean Journal of Emergency Medical Services
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    • v.26 no.2
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    • pp.87-96
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    • 2022
  • Purpose: By analyzing the health status of emergency patients on islands in the Jeollanam-do province, this study aims to provide basic data for proposed future medical emergency services on the islands. This information includes monthly and hourly statistics on patients' characteristics, patient frequency, an analysis of first aid procedures, response times, and time spent at hospitals. Methods: The study analyzed the monthly and hourly frequency of emergency patients, first aid status and procedures, general patient characteristics, accident types, patient cognitive status and agility, marine police response times, and frequency and percentile of hospital dispatch times. Results: 1Q and #q show the highest patient turnover rate in one year. 50.5% of daily patients are admitted between 4 PM and 12 PM. The hospital dispatch time is within a one- to two-hour window for 54.0% of all patients. Conclusion: The emergency medical service system for the Jeollanam-do province islands and seas is available to all Korean residents, citizens, and visitors. It is necessary to implement an emergency medical system for the relevant organizations.

Maritime Delimitation and Joint Resource Development in the East China Sea (동중국해 해양경계획정과 자원공동개발)

  • LEE, Seok-woo;PARK, Young-kil
    • Strategy21
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    • s.30
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    • pp.177-199
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    • 2012
  • As is generally known, the sovereignty dispute over the Senkaku Islands between China/Taiwan and Japan was triggered by a report commissioned by the UN in 1968, which reported the possibility of a substantial amount of petroleum and natural gas buried in the South China Sea. When the administrative authority over the Ryukyu Islands was transferred from the US to Japan in 1972, jurisdiction over the Senkaku Islands was also transferred. A dispute ensued between China (Taiwan) and Japan over the Senkaku Islands except during the period in which formal relations were established between the two states. This paper will take a look particularly at the events that occurred in the 2000's and discuss their recent trends and aspects of the dispute. Though China and Japan agreed to joint resource development in 2008, the agreed zone was a very small area adjacent to the Korea-Japan Joint Continental Shelf Development Zone, and the points of agreement have not been implemented. China has been developing four oil fields including Chunxiao in its waters adjacent to the median line asserted by Japan. However, China also has been excluding the participation of Japan, while Japan has been strongly objecting to the unilateral development of oil fields by China. If indeed the oil fields on China's side are connected past the median line asserted by Japan, then China's unilateral development will infringe upon the potential sovereign rights of Japan, thereby violating international law.

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A report on 10 unrecorded bacterial species isolated from the Korean islands in 2022

  • Seung Yeol Shin;Myung Kyum Kim;Yochan Joung;Yi Hyun Jeon;Ji Hye Jeong;Hyun-Ju Noh;Jaeho Song;Heeyoung Kang
    • Journal of Species Research
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    • v.12 no.spc2
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    • pp.54-59
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    • 2023
  • To obtain unrecorded bacterial species from Korean islands, various samples were collected from the islands in 2022. After plating the samples on marine agar or Reasoner's 2A, and incubating aerobically, approximately 1,200 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 10 strains showed ≥98.7% 16S rRNA gene sequence similarity with the bacterial species that were validly published but not reported in Korea. The unrecorded bacterial strains belong to three phyla, five classes, 10 orders, 10 families, and 10 genera, which are assigned to Sphingomonas, Falsirhodobacter and Asticcacaulis of the class Alphaproteobacteria; Colwellia and Halomonas of the class Gammaproteobacteria; Chitinophaga of the class Chitinophagia; Chryseobacterium of the class Flavobacteriia; Microlunatus, Zhihengliuella, and Streptomyces of the class Actinomycetia. The details of the unreported species including Gram reaction, colony and cell morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.

Flow characteristics of Geumo Islands Sea area by numerical model experiments (수치실험을 통한 금오열도 해역의 해수유동 특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.2
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    • pp.159-174
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    • 2022
  • Flow prediction was carried out through observational survey and three dimensional multi-layered numerical diagnostic model experiment to clarify the time and spatial structure of tidal current and residual flow dominant in the sea exchange and material circulation of the waters around Geumo Islands in the southern waters of Korea. The horizontal variation of tidal current is so large that it causes asymmetric tidal mixing due to horizontal eddies and the topographical effect creating convergence and dispersion of flow direction and velocity. Due to strong tidal currents flowing northwest-southeast, counterclockwise and clockwise eddies are formed on the left and right sides of the south of Sori Island. These topographical eddies are created by horizontal turbulence and bottom friction causing nonlinear effects. Baroclinic density flows are less than 5 cm/s at coastal area in summer and the entire sea area in winter. The wind driven currents assuming summer and winter seasonal winds are also less than 5 cm/s and the current flow rate is high in winter. Density current in summer and wind driven current in winter have a relatively greater effect on the net residual flows (tidal residual current + density current + density driven current) around Geumo Islands Sea area.

Secondary human impacts on the forest understory of Ulleung Island, South Korea, a temperate island

  • Andersen, Desiree
    • Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.202-211
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    • 2019
  • Oceanic islands are biologically important for their unique assemblages of species and high levels of endemism and are sensitive to environmental change because of their isolation and small species source pools. Habitat destruction caused by human landscape development is generally accepted as the main cause of extinction on islands, with exotic species invasion a secondary cause of extinction, especially on tropical islands. However, secondary impacts of human development (e.g., general degradation through resource use and exotic species introduction) are understudied on temperate islands. To determine secondary impacts of human development on the understory vegetation community, 90 field sites on Ulleung Island, South Korea, were sampled during the summer of 2016. Understory vegetation was chosen as it is a proxy for ecosystem health. Diversity and percent cover of introduced, native, and endemic species were tested against proximity to developed areas and trail usage using a model selection approach. Diversity was also tested against percent cover of three naturalized species commonly found in survey plots. The main finding was that distance to development, distance to town, and trail usage have limited negative impacts on the understory vegetation community within best-supported models predicting native and introduced cover and diversity. However, endemic species cover was significantly lower on high usage trails. While there are no apparent locally invasive plant species on the island at the time of this study, percent cover of Robinia pseudoacacia, a naturalized tree species, negatively correlated with plot diversity. These findings indicate that forests on Ulleung Island are not experiencing a noticeable invasion of understory vegetation, and conservation efforts can be best spent preventing future invasions.

Exploring on the Defense Strategies against Hervivory of Several Broad-leaved Tree Species in Solomon Islands (솔로몬제도에 생육중인 몇 활엽수종의 초식에 대한 방어전략 탐색)

  • Kim, Gab-Tae
    • Korean Journal of Environment and Ecology
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    • v.24 no.5
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    • pp.611-616
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    • 2010
  • To explore on the defense strategies against hervivory of broadleaved tree species growing in tropical rain forest, Solomon Islands, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves of 26 tree species, collected from the trees growing in Guadalcanal, New Georgia, and Tetepare islands, were investigated from Feb. 25 to March 5, 2010. The results are summarized as follows. Six tree species including Terminalia catappa(23.08%) among total 26 species have domatia structure. Especially, domatia of T. catappa reveals two types; pouch type and pit+tuft type. Predatory mites are observed on the leaves of only three species including T. catappa. Predatory mites' number per leaf or leaflet proved a few, 0.33~0.40. Insect pests destroying the leaf of tree species are such as aphids, Diaspididae sp., larva of Lepidoptera, and Eriosoma sp.(Pemphlogidae). Ants are co-works with aphids and Diaspididae sp., and supports herbivores. These results indicate that protective mutualisms between tree and predatory mites may be less frequent in woody species of tropical rain forest in Solomon Islands.

Recruitment characteristics of jack mackerel, Trachurus japonicus, in the waters around the Geumo Islands by using both sides fyke nets (각망을 이용한 금오열도 주변해역 전갱이의 연안가입특성 연구)

  • Kim, Hee-Yong;Choi, Mun-Seong;Seo, Young-Il;Lee, Sun-Kil;Cha, Hyung-Kee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.356-368
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    • 2011
  • Species composition of fishes and the recruitment properties of jack mackerel, Trachurus japonicus, in the waters around the Geumo Islands in the mid-South Sea were investigated by using both sides fyke nets every month from February to December 2010. During study period, a total of 30,503 fishes (1,380.4 kg) were collected and classified into 2 classes, 16 orders, 61 families and 121 species. The dominant species was jack mackerel occupying 80.5% of total individuals and 44.4% of total biomass. The fork length range of jack mackerel was 5.5-26.8 cm and individuals about 6 cm was appeared only in the middle and southern area of the Geumo Islands in May. The new recruitment of jack mackerel appeared from May in the waters around the Geumo Islands is probably caused by the warm water intrusion associated with the development of stratification due to the extinction of seasonal coastal cold waters by the increase of solar radiation heat. Furthermore, the jack mackerels less than 6 cm recruiting in the mid-South Sea in spring were considered as mixed ones by individuals spawned in the East China Sea and in the waters around the Jeju Island considering the collected time, migration period and spawning time of them.

The Characteristics of Environmental Friendly Tourism in the South Pacific Islands: A Case Study of Ecotourism in Fiji Islands (남태평양제도의 환경친화적 관광특성 -피지(Fiji)의 생태관광을 사례로-)

  • Choe, Jae-Woo
    • Journal of the Korean association of regional geographers
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    • v.12 no.1
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    • pp.124-141
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    • 2006
  • Fiji is referred to as the hub of the South Pacific as it lies on the major sea and air transport routes in the region. Tourism, the fastest growing industry within the global economy, is already well established within the country. This paper aims to explore the characteristics of ecotourism in Fiji Islands as a foreign area study. To achieve the objectives, this research carried out a literature review before taking several field surveys in Fiji Islands. Research areas are Raintree Lodge in Suva, Kula Ecopark near Sigatoka, Sigatoka Sand Dunes National Park, Nalesutale Fijian indigenous village near Nadi. Most of all facilities and ecotour programs are developed for environmental, economical and educational effects. The case studies of Fiji present a good model of how to succeed in ecotourism and conservation management to Korea. In addition, this research will provide effective regional policies for the environmental friendly tourism in Korea.

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Community Structure of Arbuscular Mycorrhizal Fungi in the Islands of Chungnam, Korea (충남 섬 지역 근권 토양의 수지상균근균 군집 구조)

  • Lee, Jeong-Youn;Lee, Eun-Hwa;Ka, Kang-Hyeon;Eom, Ahn-Heum
    • The Korean Journal of Mycology
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    • v.44 no.1
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    • pp.16-22
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    • 2016
  • Five islands (Sinjindo, Mado, Daenanjido, Wonsando, and Sapsido) and the coastal area (Muchangpo) in Chungnam, Korea, were selected to determine the diversity of arbuscular mycorrhizal (AM) fungi. Soil-inhabiting AM fungi were isolated and identified on the basis of morphological characteristics and sequence analyses of 18s rDNA. The differences in the fungal community structures were compared among sites. As a result, 24 species of AM fungi were identified, of which two species of AM fungi, Acaulospora brasiliensis and Redeckera fulvum, were isolated for the first time in Korea. This study revealed that AM fungal spore abundance was low and the genus Acaulospora was dominant in most of the islands. AM fungal community structures in five Islands were highly similar. However, the coastal area, Muchangpo, had different AM fungal community structure from the islands.