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To examine genetic divergences of two endemic Sorex caecutiens subspecies from Korea (S. c. hallamontanus in Korean Jeju Island and S. c. annexus in the mainland Korean Peninsula), we obtained partial cytochrome oxidase I (COI) sequences (429 bp) and complete cytochrome b sequences (1,140 bp) from the two Korean subspecies, and we compared these sequences to the corresponding sequences of S. caecutiens, obtained from GenBank. We found that Jeju S. c. hallamontanus is one of three clades within S. caecutiens, with an average Jukes-Cantor distance of 1.57% in the COI sequences and the distance of 2.07% and 11 fixed site differences in the cytochrome b sequences, indicating that Jeju S. c. hallamontanus is one endemic subspecies with concordant genetic distinctness, although further analyses with nuclear DNA sequences are necessary to confirm these findings. However, S. c. annexus from the mainland Korean Peninsula was not divergent from S. c. macropygmaeus from northeastern China and adjacent Russia, indicating that S. c. annexus from the mainland Korean Peninsula is another endemic subspecies with only morphological differences, although it is necessary to reexamine the subspecies status of S. c. annexus.

Two stichotrichid ciliates, collected from marine waters in Jeju Island, were identified as Afroamphisiella multinucleata Foissner et al., 2002 and Pseudokahliella marina (Foissner et al., 1982) Berger et al., 1985. They are recorded for the first time in Korea. The descriptions are based on examinations of living as well as protargol- impregnated specimens. These species are characterized as follows. Afroamphisiella multinucleata has a body size in vivo of 70-95×20-35 μm; elongate rectangular in shape; contractile vacuole located slightly above mid-body. The adoral zone is bipartited into 3 distal and 13-17 proximal membranelles and occupies 28-35% of the body length. The frontal row comprises 1-4 cirri and one buccal cirrus. The amphisiellid median cirral row is composed of 14-21 cirri, 10-19 left marginal cirri, and 21-30 right marginal cirri. Cortical granules are yellowish. 11-20 globular/ellipsoidal macronuclear nodules arrange proximally along the cell margins. Pseudokahliella marina has a body size in vivo of 110-195×40-110 μm and broadly elliptical in shape. The adoral zone of the membranelles occupies 50-60% of the body length, and is composed of 41-70 membranelles. A prominent frontal scutum is present. The contractile vacuole is located below the mid-body. There are 11- 13 frontoventral rows, including marginal rows. Caudal cirri and transverse cirri are absent. Three invariable non-fragmented bipolar dorsal kineties are present. The left and right marginal rows are composed of 22-35 and 28-40 cirri, respectively. Colourless cortical granules are present. 8-11 spherical/ellipsoidal macronuclear nodules are connected with each other by thread-like tructures, forming an inverted C-shape.

The objective of this study was to determine the degree of mitochondrial DNA (mtDNA) divergence between two subspecies of Mustela sibirica from Korea (M. s. coreanus on the Korean Peninsula and M. s. quelpartis on Jeju Island) and to examine the taxonomic status of M. s. quelpartis. Thus, we obtained complete sequences of mtDNA cytochrome b gene (1,140 bp) from the two subspecies, and these sequences were compared to a corresponding haplotype of M. s. coreanus, downloaded from GenBank. From this analysis, it was observed that the sequences from monogenic M. s. quelpartis on Jeju Island were identical to the sequences of four M. s. coreanus from four locations across the Korean Peninsula, and that the two subspecies formed a single clade; the average nucleotide distance between the two subspecies was 0.26% (range, 0.00 to 0.53%). We found that the subspecies quelpartis is not genetically distinct from the subspecies coreanus, and that this cytochrome b sequencing result does not support the current classification, distinguishing these two subspecies by pelage color. Further systematic analyses using morphometric characters and other DNA markers are necessary to confirm the taxonomic status of M. s. quelpartis.

Impacts of land use changes and groundwater management actions on groundwater quality were evaluated at the island scale with spatiotemporal trends of NO-N and Cl concentrations in groundwater of Jeju Island, Korea. The temporal trends from 1993 to 2012 in the concentrations of NO-N and Cl from more than 3900 wells were estimated using the Mann-Kendall trend test and Sen's slope analysis and compared with the land use change trend for the period 1995-2009. The results indicate that the upward trends in NO-N were associated with the expansion of agricultural lands, whereas Cl trends were considered to be affected by other factors in addition to the land use changes. In the mid-mountainous region, the deterioration in the groundwater quality by the both NO-N and Cl was expected due to the continuous expansion of agricultural lands. In the lowland area, the NO-N and Cl components showed different trends depending on the regions. In the eastern area, increasing trends in NO-N were observed due to the development of new agricultural areas, while the Cl concentration was observed to decrease as a result of the regulation on groundwater extraction to reduce seawater intrusion. Our study highlights that a comprehensive interpretation of trends in NO-N and Cl and land use changes for long-term periods can provide useful insights to prepare for suitable groundwater management plans in the whole island perspective. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the use of Bacillus amyloliquefaciens as a probiotic source in the diet of rock bream, Oplegnathus fasciatus. A total of 210 fingerlings (25.4 ± 0.13 g) were divided into two groups, three replicates each; control (C) and probiotic (P) group (35×3=105 fish per group). C group was fed a basal diet without probiotic while P group was fed with B. amyloliquefaciens spores at a concentration of 1.4 × 106 colony-forming units per gram (CFU/g) of feed. After 90 days, P group fish showed significant improvements in body weight (BW), weight gain (WG), specific growth rate (SGR) and food conversion ratio (FCR) when compared with C group fish. Also, in bi-weekly assessments, serum protein and glucose level showed a significant increase (p<0.05) in probiotic fed fish compared with the control group. Similar increase in serum antioxidant and lysozyme activity was found in the probiotic fed fish group. However, there was a significant decrease in triglyceride and total cholesterol along with increased alanine aminotransferase (ALT) and aspartate amonotransferase (AST) levels in probiotic diet fed fish compared to the control. After seventy days the fish were challenged with Streptococcus iniae and mortality of the probiotic fed fish was significantly lower (p<0.05) when compared with the control. These results demonstrate the benefit of incorporation of B. amyloliquefaciens as a feed supplement to improve the health status of Oplegnathus fasciatus challenged with Streptococcus iniae. [ABSTRACT FROM AUTHOR]

Recently a significant population migration to rural areas has been occurring in relation to both rural and urban areas in Korea. This urban-rural migration is characterized by region. On Jeju Island the number of Return Non-Farm Households provides the overwhelming majority, unlike other regions. This has partially been the result of the geographical location and tourism industry of Jeju Island. This migration tendency is causing a transformation in the rural space. Thus this paper aims to describe and determine how an increase in urban-rural migrants causes commodification of a rural-coastal village, both in terms of the reasons and the processes in order to understand rural spatial transformation by in-migrants. As a result, service activities by in-migrants in Woljeong village are associated with commodification of the village in terms of consumption of the village landscapes. This includes the ocean view and sales of farm lands and houses. Commodification of the village has overheated commercialization of the village space and competition in the same field of business. Finally, a spatial division between the existing 'spatial practices' of the village natives and the commercialized place of new stakeholders has occurred. This means that the rural space and identity have transformed in Woljeong-Ri. [ABSTRACT FROM AUTHOR]

While environmental and energy concerns have become global issues, the government of South Korea has made notable efforts and formulated plans for the diffusion of renewable energy generation facilities for the nation's public and governmental institutions. Accordingly, Jeju Island has become one of the most promising locations for utilizing renewable energy resources. This study aims to propose potential configurations for renewable energy generation facilities (mainly solar and wind energy facilities) in response to the electricity demand of the main local governmental offices of Jeju Special Self-Governing Province. The study utilizes the hybrid optimization of multiple energy resources software to simulate two optimized configurations for generation at a cost of energy of $0.306 per kWh (independent) and $0.204 per kWh (grid-connected) with 100% renewable fraction for the island. The implications of the simulation results and limitations of the study are discussed. [ABSTRACT FROM AUTHOR]

Several recent studies suggest the hypothesis that the El Niño-Southern Oscillation (ENSO) is an important factor controlling the Holocene East Asian Monsoon (EAM). However, the mechanism underlying this influence remains unclear due to the lack of high-resolution paleoclimate records from the coast of East Asia. Here, we provide a new record of late Holocene climate change in coastal East Asia based on multi-proxy evidence (pollen, organic content, magnetic susceptibility, grain size) obtained from a sediment core from Jeju Island, South Korea. As Jeju Island is strongly influenced by the Kuroshio flow, our sediment proxy records contain ENSO signals from the tropical Pacific. The study area was affected by dry/cool conditions in the western tropical Pacific (WTP) between 4350 and 1920 cal yr BP when El Niños were frequent, and by rapid warming/wetting and forestation since 1920 cal yr BP when La Niñas were more common. Jeju Island was relatively dry/cool between 2100 and 1600, 1300–1200, 1100–1000, 800–650, and 300–50 cal yr BP, as opposed to the Galápagos Islands, which were relatively wet/warm, reflecting the ENSO-related negative correlation between eastern and western margins of Pacific. Wet conditions may have prevailed during the early Little Ice Age (LIA) (620–280 cal yr BP) despite consistent cooling. This period of high precipitation may have been associated with the increased landfall of typhoons and with warmer Kuroshio currents under La Niña-like conditions. According to our results, EAM on the East Asian coastal margin was predominantly driven by ENSO activity, rather than by the precession effect. Paleoclimatic data from Jeju Island, with its insular position and closeness to warm Kuroshio currents, provide clear evidence of these ENSO influences. [ABSTRACT FROM AUTHOR]

Poorly constructed wells can cause deterioration of groundwater quality by carrying surface contaminants into a deep subsurface aquifer system. In this study, the impact of leaky wells on groundwater contamination was quantitatively evaluated in a layered aquifer system of the Gosan agricultural fields, Jeju Island, Korea, where degradation in groundwater quality by nitrate has been reported. We introduce a leaky-well module and a double-domain integration method to compute nitrate cross-contamination through a layered aquifer system. The simulation results clearly revealed that the leaky wells rapidly degraded the water quality of the underlying aquifer by acting as a direct pathway for nitrate-rich shallow groundwater. The model results predicted that in order to decrease the NO 3 -N concentration at the regional groundwater wells below the maximum contamination level (MCL), the maximum allowable fertilizer amount of Gosan would be 45–65% of the currently applied fertilizer level, whereas sealing of the regional groundwater wells would rapidly decrease the NO 3 -N concentration below the MCL without reducing fertilizer usage. Our study demonstrated that the well conditions and hydrogeological system play major roles in the occurrence of nitrate in the underlying aquifer in Gosan; therefore, a proper groundwater management plan against nitrate contamination should be established on the basis of a comprehensive understanding of the hydrogeologic system of the area. [ABSTRACT FROM AUTHOR]

Submarine groundwater discharge (SGD) is a global phenomenon that carries large volumes of groundwater and dissolved chemical species such as nutrient, metals, and organic compounds to coastal zones. We report the influence of SGD on the coastal waters of Jeju Island, Korea, using high-resolution aerial thermal infrared (TIR) mapping techniques and field investigations. An aircraft-based system was implemented using a cost-effective TIR camera for aerial TIR mapping. Ground-based calibrations and system integration with GPS/IMU (global positioning system/inertial measurement unit) were performed for the aerial systems. The aerial surveys showed distinct low-temperature signatures of SGD along the coasts of Jeju Island, revealing large groundwater inputs from the coastal aquifers to the ocean. Multiple aerial surveys over a range of seasons and tidal stages revealed that SGD rates dynamically affect the sea surface temperature (SST) of the coastal zone. The in-situ measurements supported that SGD has a substantial influence on the coastal water chemistry as well as SST. Our observations highlight the extent to which aerial-based TIR mapping can serve as a powerful tool for studying SGD and other coastal processes. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Limited knowledge is available on the regeneration of Korean fir ( Abies koreana Wilson), an endemic plant species, growing on the upper part of Mt. Hallasan, a volcanic mountain, located in the central part of Jeju Island, Korea. A forest stand with the size of 1 ha dominated by Korean fir trees was established and all the trees with DBH 2 cm or larger were mapped and surveyed. Initial analysis indicated that the numbers of saplings with their DBHs between 2 cm and 10 cm were very small and that there was a big gap in the frequency of the number of saplings regenerated from the forest stand. It seems clear that the regeneration of the Korean fir trees was disturbed for longer than the last two decades, potentially by the browsing of the seedlings by ungulate including Siberian roe deer and by the physical hindrance of the dwarf bamboo to the development of the saplings of the Korean fir. Urgent measures and extensive studies are needed to promote the natural regeneration of the tree species on the dynamics of the forest regeneration and the mechanism of forest development of the forests on the Mt. Hallasan, Jeju Island, Korea. [ABSTRACT FROM AUTHOR]

The diversity of benthic foraminiferal species was investigated around and along a transect of Jeju Island (South Korea). A total of 20 sediment samples were collected from water depths of 44 to 109 m in November 2011. Due to its substrate heterogeneity, position in between temperate and subtropical zones, and the different water masses influencing the location, Jeju Island has been suggested as an area that is able to support high meiobenthos biodiversity. We taxonomically identified a total of 304 benthic foraminiferal species belonging to 142 genera. Among them, 180 species are newly recorded for the Korean coastal water. On the basis of our findings, and taking into account previous publications, it was possible to infer the total benthic foraminiferal diversity of the Korean Peninsula. Accordingly, this new literature survey documents the presence of 818 species belonging to 239 genera, 89 families, and 40 superfamilies. These values are remarkably high and can be readily compared to those reported in area basins and seas like the Gulf of Mexico, the northeastern Atlantic Ocean, New Caledonia and the Aegean Sea. It must, however, be stressed that these figures might be an underestimation of total diversity, which is certain to increase if deep-sea sediments and monothalamids are also taken into account. [ABSTRACT FROM AUTHOR]

The activity concentrations of 210Po and 210Pb within phytoplankton-zooplankton-anchovymackerel in the coastal water of the Jeju Island were determined to understand their distribution and bioaccumulation along the trophic level. In the surface water, the total activity concentrations of 210Po and 210Pb were 0.83 ± 0.004 mBq kg-1 and 1.27 ± 0.03 mBq kg-1. And the dissolved activity concentration of 210Po and 210Pb were 0.75 ± 0.06 mBq kg-1 and 1.22 ± 0.09 mBq kg-1 respectively. In the phytoplankton, the concentration factor (CF) of 210Po and 210Pb were 1.5 × 105 and 2.6 × 104 shows 210Po is 5 times higher compared to 210Pb. The similar CF factor in the zooplankton of 210Po was derived as 1.4 × 105. The CF of 210Po in anchovy was increased twice compared to that in plankton. This is the evidence that there is 210Po bio-magnification in the trophic level of plankton-anchovy. However the 210Po activity concentration in the muscle tissue of mackerel was one-hundred times lower than that in anchovy. This reflects that in the trophic level of anchovy-mackerel, the bio-accumulation of 210Po is decreased. The activity concentrations of 210Po in the internal organs of anchovy and mackerel were 8 to 38 times higher than those in muscle tissues. In phytoplankton-zooplankton-anchovy, the CF of 210Pb was decreased five times along the trophic level in order. In anchovy-mackerel it was decreased by 30−70%. [ABSTRACT FROM AUTHOR]

The monitoring and prediction of temporal change in the location of the freshwater--saltwater interface including the groundwater level (GWL) is the essential information for effective management of coastal aquifer, especially for managing the saltwater intrusion. A simple and novel method for monitoring temporal change in the location of the freshwater--saltwater interface was developed and evaluated by applying to a coastal aquifer in Jeju Island, resulted in obtaining time series data of the freshwater--saltwater interface level (FSL) successfully. And applicability of artificial neural network-based time series models to prediction of the GWL and the FSL is evaluated using the observed data from the site. The prediction result shows that the input configuration including autoregressive components enhances the model performance and the recursive prediction models can be useful for the long-term prediction of the GWL and the FSL in this case study. [ABSTRACT FROM AUTHOR]

The Oriental fire-bellied toad ( Bombina orientalis ) is a commonly used study organism, but knowledge of its evolutionary history is incomplete. We analyze sequence data from four genetic markers (mtDNA genes encoding cytochrome c oxidase subunit I, cytochrome b, and 12S–16S rRNA; nuDNA gene encoding recombination activating gene 2) from 188 individuals across its range in Northeast Asia to elucidate phylogeographic patterns and to identify the historic events that shaped its evolutionary history. Although morphologically similar across its range, B. orientalis exhibits phylogeographic structure, which we infer was shaped by geologic, climatic, and anthropogenic events. Phylogenetic and divergence-dating analyses recover four genetically distinct groups of B. orientalis : Lineage 1—Shandong Province and Beijing (China); Lineage 2—Bukhan Mountain (Korea); Lineage 3—Russia, Northeast China, and northern South Korea; and Lineage 4—South Korea. Lineage 2 was previously unknown. Additionally, we discover an area of secondary contact on the Korean Peninsula, and infer a single dispersal event as the origin of the insular Jeju population. Skyline plots estimate different population histories for the four lineages: Lineages 1 and 2 experienced population decreases, Lineage 3 remained stable, while Lineage 4 experienced a sharp increase during the Holocene. The timing of the population expansion of Lineage 4 coincides with the advent of rice cultivation, which may have facilitated the increase in population size by providing additional breeding habitat. [ABSTRACT FROM AUTHOR]

Corals reefs and communities support a wide range of flora and fauna. The complete richness and abundance of faunal communities in either coral reefs or communities is not fully understood. This is especially true for high-latitude coral communities. In this work, we carried out an analysis of an Alveopora japonica associated mollusk assemblage, in Jeju Island, Korea. A. japonica is one of the major coral species present in high abundance (88-155 colonies m), with a high recruitment rate (7.8 juvenile corals m yr) in Jeju Island, and may serve as a habitat for other benthic organisms. In 2012, a total number of 579 A. japonica colonies with sizes ranging between 15.1-346.7 cm in the surface area were collected from a 1m× 10m quadrat installed at a depth of 10 m at Keumneung, on the northwest coast of Jeju Island. Numerous benthic invertebrates were found to be associated with A. japonica colonies. Twenty-seven bivalves and gastropods were identified, including a boring mytilid, Lithophaga curta, and an arcid, Barbatia stearnsi. A zonalgeographical examination of the distribution ranges of these mollusks revealed a majority of warmer water species. Our observations also showed that A. japonica may be providing a habitat to grazing gastropod, Turbo cornutus, and encrusting Spondylidae and Chamidae bivalves. A. japonica forms a coral carpet with a distinct assemblage of bivalves. It is thought that the presence of these mollusks species in the coral indicates its use as a nursery for juvenile species, a ready food supply of organic detritus, and a refuge from predators. [ABSTRACT FROM AUTHOR]

The Conus Linnaeus, 1758 is a large genus of marine gastropod mollusks belonging to the family Conidae. The Conus species are mostly distributed in the tropical waters of the world, and they are especially abundant in the Indo-West Pacific region. To date, more than 600 species, most of which are predatory species, have been named worldwide in this genus and only six species have been recorded in the Korean waters. Conus sponsalis Hwass in Bruguiere, 1792 was collected from Jeju Island and identified as a new Korean record. In this study, we report a description of the shell morphology of the species.

We report classical swine fever outbreaks occurring in naive pig herds on Jeju Island, South Korea, after the introduction of the LOM vaccine strain. Two isolates from sick pigs had >99% identity with the vaccine stain. LOM strain does not appear safe; its use in the vaccine should be reconsidered. [ABSTRACT FROM AUTHOR]

We determined the complete chloroplast genome sequence of the peatmoss Sphagnum subsecundum Nees from Mt. Halla in Korea. The total size of the chloroplast genome was 140,136 bp, and it consisted of a large single-copy region (LSC) of 98,064 bp, a small single-copy region (SSC) of 21,388 bp, and two copies of inverted repeat (IRa and IRb) regions of 10,342 bp each. The genome encoded a set of 130 genes, comprising 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. This species formed a monophyletic clade with S. orientale and S. lenese as the result of ML phylogenetic analysis based on whole gemone sequence of 15 species including one outgroup species. [ABSTRACT FROM AUTHOR]

The biodiversity of benthic invertebrates in the intertidal and subtidal regions of Gapado, Beomseom, and Munseom islets was surveyed twice in May and September 2013 to study the state of biodiversity in Seogwipo, Jeju Island. As a result, a total of 77 species, 46 families, 25 orders, 14 classes, and nine phyla of benthic invertebrates were found. The species which were found, by taxon, consisted of the following: 26 species of Cnidaria (34%), 24 species of Mollusca (31%), seven species of Chordata (9%), six species of Arthropoda (8%), six species of Porifera (8%), five species of Echinodermata (7%), one species of Bryozoa (1%), one species of Annelida (1%), and one species of Ctenophora (1%).

With integration of a battery energy storage system (BESS) into the wind power system, the wind power variation can be mitigated to dispatch a constant power to the grid. To effectively supply the constant power dispatch to the grid with a limited BESS, the power dispatch capability should be defined primarily at beginning of each dispatching interval to cooperate with the transmission system operator. This study introduces a method to determine the power dispatch capability of a wind‐battery hybrid power system with the minimal battery capacity. The power dispatch capability is decided under the condition that the battery power is maintained below its rating and that the state of charge of the battery is guaranteed within a safe range. For economic BESS operation, the battery capacity, including the power and energy ratings, is also determined cost‐effectively to obtain the constant power dispatch. Based on the long‐term wind power profile, the authors develop the determination process to minimise the battery capacity which ensures that the BESS sufficiently mitigates wind power variation to dispatch the constant power into grid under all wind conditions. To evaluate the proposed determination method, a case study is carried out with a 3‐MW wind turbine generator and real wind speed data measured on Jeju Island in Korea. [ABSTRACT FROM AUTHOR]

Recent and shell mound bivalves ( Glycymeris sp.) were collected from two sites (Sangmori and Udo, Jeju Island) to investigate paleoceanographic conditions using high resolution stable isotope and trace element data. The radiocarbon ages are about 3210 ± 50 and 4210 ± 60 BP for the Sangmori and Udo shell mounds, respectively. Both oxygen and carbon isotopic compositions of the shell mound bivalve shells show clear seasonal cycles with depleted values during summer and the coeval trend, which indicates that they were controlled by freshwater input. Similar ranges of both isotopes indicate that shallow seawater conditions near the Sangmori and Udo shell mounds are more or less similar. However, more negative oxygen and carbon isotope values of the shell mound bivalves than the recent counterpart suggest that surface seawater salinity near Jeju Island was lower due to the increase in Changjiang River Discharge. Mg contents of the recent bivalve reflect surface seawater temperature changes whereas Sr and Ba contents were controlled by nutrient concentrations directly influenced by Changjiang River Discharge. Geochemical data of the recent and shell mound bivalves may imply higher precipitation (more intense East Asian Summer Monsoon activity) at ∼3.2 and 4.2 ka under the influence of the terminal stage of Holocene climatic optimum in south China or may reflect smaller fluctuating peaks during its decline. [ABSTRACT FROM AUTHOR]

Granite-derived soils are widespread in the farmland of Korea in general. In contrast, Jeju Island has mainly volcanic ash soils. Soils and weather condition in Jeju Island created a unique agricultural system. We identified the features of ground-dwelling insects in farmlands of Jeju Island. This study was conducted in four areas ( Samdal-ri and Susan-ri in Seogwipo city, and Dongmyeong-ri and Suwon-ri in Jeju city) in Jeju Island, Korea. Field surveys were carried out twice in summer ( June) and autumn ( September) in 2013. Ground-dwelling insects were sampled quantitatively by using pitfall traps. As a result, in total 3322 individuals, 137 species, 48 families and 8 orders were investigated in farmlands of Jeju Island. Especially, members of Coleoptera and Hymenoptera accounted for a large proportion of ground-dwelling insect communities. The numbers of species and individuals for major taxonomic groups showed significant regional and seasonal differences. This study implied that the seasonal and regional differences of ground-dwelling insect communities were affected by surrounding land use patterns, life history patterns of each taxonomic group and farmland management. [ABSTRACT FROM AUTHOR]

We review geophysical and geochemical properties in the vicinity of the stagnant Pacific slab beneath northeast China, Korea and Japan to understand the origin and current state of intraplate volcanism in East Asia. East Asia has been susceptible to intensive volcanism since the Cretaceous. In particular, during the Cenozoic, Jeju Island, Korea is the most significant volcanic construct in East Asia. The generation of adakites and A-type granitoids littered throughout East Asia during the Cretaceous has been previously explained by the subduction of the Izanagi–Pacific ridge system. However, a recently revised plate reconstruction model does not comprise such a tectonic episode and consequently fails to explain adakites in arc magmatism during the Cretaceous. Thus, we propose an alternative hypothesis: temporal plume–slab interaction on the source of East Asian magmatism in order to trigger the adakites in arc magmatism without ridge subduction. In addition, we provide an overview on the tectonics and volcanism of Jeju Island during the Cenozoic in the context of the lithospheric structure from seismological constraints and recent geochemical results. The main scientific aims are to understand the consequences of mantle mixing in response to long-term subduction and subsequent changes on the stress state to determine the distribution of chemical heterogeneities, and thus define the origin and development of intraplate volcanism in East Asia. Although geophysical and geochemical data for Jeju Island are not sufficient at present, we strongly state that Jeju Island and the surrounding regions hold a key to unraveling the source of intraplate magmatism since the Cretaceous. [ABSTRACT FROM AUTHOR]

A total of 19 species of three genera Dinophysis, Histioneis, and Parahistioneis of the family Dinophysaceae are reported here from samples obtained using a 20-µm mesh net from June 2006 to December 2014 around Jeju Island including the East China Sea, and 16 of these species are new to Korean waters. A checklist of the three genera of dinoflagellates reported from coastal and oceanic Korean waters is presented. Short descriptions and synonyms are given for each species. The dinoflagellates of the family Dinophysaceae belong to mostly marine species, and include many tropical and/ or subtropical species. Recently, the composition of dinoflagellate species has changed around Jeju Island as well as in Korean waters due to global warming and climate change. Tropical and subtropical dinoflagellates occur frequently in the coastal waters of Jeju Island, which reflects the ecosystem shift around the sea adjacent to Jeju Island from a temperate to a subtropical / tropical region. [ABSTRACT FROM AUTHOR]

The concentrations of nutrients and dissolved organic matter (DOM) in the coastal waters off Jeju Island, Korea, are known to be influenced mainly by submarine groundwater discharge (SGD) and fish-farm effluents, in addition to the background open-ocean seawater from the Tsushima Current. However, the differentiation of the effect of fish-farm effluents from SGD is very challenging since most of the farms in this island utilize groundwater as a rearing water. Thus, in this study, we measured the concentrations of nutrients and fluorescent DOM (FDOM) in seawater, fresh groundwater (FGW), and farm water in two coastal areas off Jeju Island, in May and August 2021, in order to determine the effect of SGD versus fish-farm effluents. The results showed that humic-like FDOM (FDOM H) and NH 4 + concentrations were greatly enriched owing to organic matter decomposition in the farm waters. We used FDOM H , as a tracer for the farm effluent. The end-member mixing model for FDOM H and salinity showed that FGW contributed about 73% of NO 3 − (avg. 17 ± 20 μM), whereas the farm effluent contributed about 95% of NH 4 + (avg. 5.6 ± 4.1 μM) and 71% of FDOM H (avg. 0.86 ± 0.49 R.U.) in the coastal waters. Thus, our result shows that fish-farm effluents can be an important source of anthropogenic DOM and nutrients in coastal waters, where farms are being operated intensively. • Fresh groundwater is a dominant source of NO 3 − in coastal waters off Jeju • Humic-like FDOM and NH 4 + concentrations were greatly enhanced in fish-farm waters • Humic-like FDOM can trace fish-farm effluent sources in the coastal waters [ABSTRACT FROM AUTHOR]

Understanding the natural variability of the East Asian monsoon (EAM) system, mainly consisting of summer and winter monsoons, is essential to predict future climate changes that will influence agricultural and industrial activities in the highly populated region. To date, the variability of the East Asian winter monsoon (EAWM) and its controlling factors is still unclear in downwind areas that experience the Siberian High, mostly due to the lack of a high-resolution winter monsoon index. Based on the correlation between diatom variations in a volcanic cone of Jeju Island, South Korea, with past regional climate changes (e.g., temperature, dust, and sea ice) and solar activity, in this study, we evaluated the changes in the climate from the sum of acidophilous species (SAS), known to be mainly controlled by the pH of the prevalent water pool, and inferred that the SAS increased during the cold and dry periods (e.g., Little Ice Age and Dark Age Cold Period). Furthermore, millennial-timescale fluctuation in the detrended SAS during the past 8000 years, with peaks at ~500, 1500, 3000, 5600, 6600, and 7600 cal yr B·P., corresponded to the ice-rafted events reported from studies conducted on subpolar ocean sediments and solar activity. In this study, we suggest that, historically, high-latitude climate change driven by solar activity has controlled the EAWM; additionally, we support the application of the SAS in Jeju Island as a high-resolution EAWM index. • The diatom variation is correlated to climate change during the Holocene • The present pH changes depend on the season and indicate the EAWM variability • Acidophilous species correlate with the Little Ice Age and Dark Ages Cold Period • During Holocene, the relative abundance of acidophilous species is related to Bond events. • The EAWM was mainly controlled by the solar irradiance during the Holocene [ABSTRACT FROM AUTHOR]

In order to elucidate the genetic diversity and taxonomic status of Siberian roe deer ( Capreolus pygargus) from the Korean peninsula, partial sequences of the mitochondrial cytochrome b gene were analyzed. We collected 57 roe deer samples from Mainland and Jeju Island between July 2004 and June 2009. A total of 50 sequences (1,070 bp) were obtained, and seven haplotypes were defined. Five haplotypes were found from Mainland, and two were discovered from Jeju Island. The genetic diversity was lower in the Jeju Island population than in the Mainland population. In addition, both the consensus neighbor-joining tree and maximum parsimony tree showed an identical topology between the Mainland and Jeju Island clades. Based on the results, two subspecies of the Korean roe deer were confirmed. Siberian roe deer in Jeju Island showed a distinct difference in the cytochrome b gene compared with other Siberian roe deer, being a unique native species inhabiting only Jeju Island in Korea. Because Siberian roe deer in Jeju Island can be classified at subspecies level, the new subspecies in Jeju was named Capreolus pygargus jejuensis in this study. For this new subspecies, reasonable conservation and management effort is needed in the future. [ABSTRACT FROM AUTHOR]

* Premise of the study: The subgenus Cernsus of the genus Prunus includes several popular ornamental flowering cherries. Of the hundreds of cultivars, P. xyedoensis ('Somei-yoshino') is the most popular and familiar cultivar in Korea and Japan and is considered to be of hybrid origin. However, the hybrid origin of P. xyedoensis and its relationship to wild P. yedoensis, naturally occurring on Jeju Island, Korea, are highly controversial. * Methods: We extensively sampled wild P. yedoensis, cultivated P. xyedoensis, and numerous individuals from other species belonging to subgenus Cerasus on Jeju Island. Samples from 71 accessions, representing 13 species and one cultivar (P. xyedoensis), were sequenced for nrDNA ITS/ETS (952 characters) and seven noncoding cpDNA regions (5421 characters) and subjected to maximum parsimony and maximum likelihood analysis. Additive polymorphisms in the ITS/ETS regions were confirmed by cloning amplicons from representative species. * Key results: The nuclear (ITS/ETS and G3pdh) and cpDNA data, along with several morphological characteristics, provide the first convincing evidence for the hybrid origin of wild P. yedoensis. The maternal parent was determined to be P. spachiana f. ascendens, while the paternal parent was unresolved from the taxonomically complex P. serrulata/P. sargentii clade. The presence of two kinds of ribotypes was confirmed by cloning, and the possible origin of cultivated P. xyedoensis from wild populations on Jeju Island was also suggested. * Conclusions: Bidirectional and multiple hybridization events were responsible for the origin of wild P. yedoensis. Extensive gene flow was documented in this study, suggesting an important role of reticulate evolution in subgenus Cerasus. [ABSTRACT FROM AUTHOR]

Spinel harzburgite to lherzolite xenoliths are entrapped in Quaternary intraplate alkali basalts on Jeju Island, South Korea. These xenoliths are unusual in containing late-stage secondary orthopyroxene, free of deformation and exsolution that is replacing olivine as the main pervasive metasomatic mineral. These xenoliths are characterized by high Mg# in olivine, orthopyroxene, and clinopyroxene (89–93) and variable Cr# of spinel (9–53), representing residues left after variable degrees of melt extraction (~ 25%). In contrast to their depleted major-element compositions, clinopyroxenes in the xenoliths are enriched in most incompatible trace elements. Clinopyroxenes display enrichment in light rare earth elements (LREE) or spoon-shaped REE with a general enrichment in La over Ce, and depletion in high field strength elements (HFSE; e.g., Nb-Ta, Zr-Hf, Ti). Orthopyroxenes (either primary or secondary) are characterized by low TiO 2 , high Al 2 O 3 , and moderate CaO contents, and resemble those of sub-continental arc peridotites from the eastern Pacific. The geochemical evidence, in addition to the formation of secondary orthopyroxene, indicates that Jeju peridotite xenoliths have been subjected to different degrees of metasomatism by subduction-related silica- and LREE-enriched fluids (or melts). However, chemical equilibrium is evident between the primary and secondary orthopyroxene, implying that the duration of post-metasomatic high temperatures enabled complete resetting/reequilibration of the mineral compositions. The metasomatic enrichment pre-dates the host Jeju Quaternary magmatism, and a genetic relationship with the host magmas is considered unlikely. We therefore propose that the Jeju peridotite xenoliths went through a two-stage evolution, with their composition primarily controlled by early fractional melt extraction, which was subsequently modified by residual slab-derived fluids (or melts). Following enrichment in the peridotite protolith in the mantle wedge, the upper mantle beneath proto-Jeju Island was transformed from a subarc environment to an intraplate environment. The Jeju peridotites, representing old subarc fragments, were subsequently transported to the surface, incorporated into ascending Quaternary intraplate alkali basalt. The result of this study implies that long term material transfer in the transformation of geotectonic setting from a subarc to intraplate may have played a significant role in the evolution of the subcontinental lithospheric mantle, resulting in the enriched mantle domains, such as EMI or EMII. [ABSTRACT FROM AUTHOR]

A Gram-stain negative, non-flagellated, non-gliding and rod-shaped bacterium, strain JHH-2, was isolated from seawater collected in Jeju Island, Korea. The novel isolate was found to grow at 25-30 °C, at pH 6.5-7.0 and in the presence of 1-2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain JHH-2 is closely related to Siansivirga zeaxanthinifaciens JCM 17682, with 16S rRNA gene sequence similarity of 96.6 %. The predominant respiratory quinone was identified as menaquinone-6 and the major cellular fatty acids were detected as iso-C, C and iso-C 3-OH. Polar lipid profiling revealed the presence of phosphatidylethanolamine, an unidentified glycolipid, four unidentified aminolipids and two unidentified lipids. The DNA G+C content of the chromosomal DNA of the type strain is 35.6 mol%. On the basis of several distinct phenotypic characteristics and phylogenetic analysis, a new species of the genus Siansivirga, Siansivirga jejunensis JHH-2 sp. nov. is proposed. The type strain is JHH-2 (= KCCM 92030 = JCM 19228). [ABSTRACT FROM AUTHOR]

The rare earth element (REE) composition of a 4.96 m-long sediment core retrieved from the Hanon paleo-maar in Jeju Island, Korea was studied to investigate the East Asian monsoon variations during the latest Pleistocene to early Holocene (22,300–9000 cal BP). The studied paleo-maar core sediment has two restricted source materials with distinctively different geochemical signatures: Asian dust blown from central Asia (especially northern China and Mongolia) and basement rock composed of trachybasalt. The REE characteristics of sediments depend on the relative contribution of these two sources and thus can be used to delineate the monsoon climate in Jeju Island. The proportion of Asian dust generally decreased gradually from 67% at 22,300 cal BP, indicative of progressive weakening of the winter monsoon strength in central Asia. Integration of the REE data with TOC and MS records reveals that the summer monsoon strength in Jeju Island decreased from 22,300 cal BP until the last glacial maximum at 18,000 cal BP, and then increased to 14,000 cal BP. The abrupt intensification of the summer monsoon occurred from 14,000 to 13,300 cal BP, followed by the weakened summer monsoon from 13,300 to 11,000 cal BP, in anti-phase with the strengthened winter monsoon in central Asia. In the early Holocene, Jeju Island experienced further intensified summer monsoon strength. [ABSTRACT FROM AUTHOR]

A new genus and two new species of ostracods are described from the Plio-Pleistocene Seogwipo Formation of the Jeju Island, Korea. In this study, Tamnacythere is erected as a new genus, and Tamnacythere seogwipoensis and Kotoracythere paiki are erected as new species. These two new species are the extinct cryophilic ostracods occurring only from the late Pliocene and early Pleistocene strata which are distributed around the Seogwipo area of the Jeju Island, Korea as well as the coastal areas on the East Sea (Sea of Japan) side of central and northern Honshu and southern Hokkaido, Japan. [ABSTRACT FROM AUTHOR]

Human history on the Korean Peninsula has left natural resource managers with a number of serious challenges regarding the preservation of biodiversity and ecosystem functions. The Korean Peninsula covers 222,403 km² and contains a mountainous interior, many islands, and biodiversity-rich coastal and marine areas. Biodiversity on the peninsula is not well documented, especially in North Korea, but the peninsula is estimated to host at least 100,000 species, and perhaps manyfold more. Roughly 6% of species identified to date are endemic, and among vertebrate species in South Korea, 29% of mammals, 14% of birds, 23% of freshwater fishes, 48% of reptiles, and 60% of amphibians are estimated to be at risk of extinction or have been extirpated from the peninsula. The situation is likely worse in North Korea. Species still occurring on the Korean Peninsula have survived near total deforestation of the landscape, heavy fishing, pollution, and, in South Korea, a period of rapid urbanization since the end of the Korean War in 1953. Conservation challenges are particularly dire in North Korea, where environmental degradation has impaired the country's ability to sustain agriculture, clean air and water, and other fundamental ecosystem services. Conservation faces significant challenges in South Korea, too, given the country's goal to continue to develop one of the world's most advanced and urbanized economies. Natural resource managers in both North and South Korea are pursuing large-scale restoration of forests, wetlands, lakes and rivers, and coastlines as a primary conservation strategy. In addition, South Korea is aggressively developing a "green economy" and is hosting international environmental meetings, attempting to take a leadership role as a convener of innovative thinking in conservation. North and South Korea are also implementing more common land protection techniques, such as the creation of national parks and other protected areas. These protected areas include the exceptional case of the 100,000-ha (250 km × 4 km) Demilitarized Zone (DMZ) that forms the border between North and South Korea. The DMZ was not created for conservation reasons, but has provided an important refuge for many species. Other well-known protected areas include Jeju Island and Baekdu Daegan Mountain, both of which host many species important for conservation. Together, these conservation actions show promise and may allow the Korean Peninsula to preserve its biodiversity and regain some of its important ecosystem services. South Korea, in particular, provides an example for attempting to balance economic development and conservation in an area with a long history of human exploitation. North Korea is much farther behind in its conservation efforts, but is now beginning planning for large-scale restoration projects, which if implemented may help reverse its long trend of environmental degradation. [ABSTRACT FROM AUTHOR]

Perceptions toward tourism development have been explicitly and extensively investigated within the tourism literature. However, there is little study of perceptions toward non-tourism development (NTD) in tourist destinations. NTD in a tourist destination may be unavoidable, because as tourism grows, the destination may need more facilities and infrastructure to meet the needs of tourists and residents. Alternatively, the NTD may not enhance tourism at all, but rather compete for space and human, financial and political resources. The objective of this study is to reveal how residents of a small tourism-oriented island, JeJu Island in South Korea, would perceive NTD and examine ramifications of a naval base for tourism preferences. Residents were clustered into three groups based on their preferences for tourism activity, Tourism Supporters, Tourism Neutrals, and Tourism Opponents. Study results revealed that the three groups differed among socio-demographic variables as well as perceived cultural and local infrastructure impacts of NTD. [ABSTRACT FROM PUBLISHER]

Volcanic rocks on Jeju Island consist mainly of intraplate alkaline lavas with subordinate intercalated tholeiite basaltic rocks. The alkaline suite can be divided into high-Al alkali (HAA) and low-Al alkali (LAA) sub-suites. We determined the Sr/Sr ratios of anorthositic xenolith plagioclases and the Sr-Nd-Pb isotope compositions of the host tholeiite basalt (Taeheungri basalt). The anorthositic xenoliths are considered to represent buoyancy-induced floating cumulates from previous tholeiite magmatism on Jeju Island. The Sr/Sr ratios of the xenolith plagioclases are highly elevated compared with those of the Jeju tholeiite lavas, including the host basalt. The Sr/Sr ratios of the Jeju volcanic rocks increase from the LAA through the HAA to the tholeiite suite. The tholeiite suite generally exhibits less radiogenic Nd/Nd ratios than the alkaline suite. In Pb-Pb space, the tholeiite suite has, in general, elevated Pb/Pb ratios compared with those of the alkaline suite at a given Pb/Pb ratio. In contrast to the Sr/Sr ratios, the two alkaline sub-suites (HAA and LAA) display indistinguishable Nd and Pb isotope compositions. Notably, some of the tholeiite and HAA suites exhibit distinctive positive anomalies in Eu and Sr in the trace element distribution pattern and the Sr/Sr ratios increase as a function of the degree of Sr or Eu enrichment. These observations, along with the relatively fractionated nature of the tholeiite and especially the HAA suites, indicate that the suites might be products of assimilation of plagioclase-rich cumulates, possibly at lower crustal depth, during parent magma evolution. Jeju volcanic rocks exhibit a mixing line between Indian mid-ocean ridge basalt-like depleted mantle and enriched mantle type 2 (EM2) components in Sr-Nd and Pb-Pb isotope correlation diagrams. The enriched component, the source of which may have been the asthenosphere, is supposed to have been higher in the Jeju tholeiite magmatism than in the alkaline magmatism. [ABSTRACT FROM AUTHOR]

Groundwater is a major source of water use in Jeju volcanic island of Korea. Due to highly permeable surface conditions, the island does not have any perennial streams or rivers. Therefore, accurate estimation of groundwater recharge and understanding groundwater system are critical to make a reliable water budget in the island. A distributed quasi steady state water balance model, WetSpass (Water and Energy Transfer between Soil, Plants and Atmosphere under quasi Steady State) was adopted to estimate spatially-varying groundwater recharge considering soil type, land use, topography, and groundwater depth. The results from the study using weather data from October 2006 to September 2007 indicated that the eastern and northern parts of the island showed relatively higher rate of recharge as compared with the western region. A total of 69% of recharge occurred in the middle of the Island where topographic elevation is greater than 200 m from the mean sea level. The total amount of recharge was 1,935.6 million tons, 41.8% of the total precipitation. The higher rate of recharge was observed in the watersheds where forest and bare soil as land uses, and sandy loam and clay loam as soil types are dominant. The total runoff was 1,142.7 million tons (24.7%) and the total evapotranspiration was 1,555.7 million tons (33.5%). The zonal hydraulic conductivities estimated with groundwater flow modeling and parameter estimation process showed a wide range of values from 1.2 m/d to 5,380 m/d. The results of groundwater flow modeling indicated that the crest of groundwater table is off-centered from the peak of Mt. Halla toward south. [ABSTRACT FROM AUTHOR]