La H.S.,Korea Polar Research Institute |
Kang M.,Gyeongsang National University |
Dahms H.-U.,Kaohsiung Medical University |
Dahms H.-U.,National Sun Yat - sen University |
And 6 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2015
This study investigated the variations in the sound-scattering layer (SSL) that were reflected from the mesozooplankton communities around the Northwind Ridge in the western Arctic Ocean. A multi-frequency acoustic survey was conducted to reveal the SSL distribution dominated by Arctic copepods in the early summer of 2010. The SSL distribution was well correlated with the salinity, nutrients and chlorophyll a (chl-a) associated with the features of the Pacific Summer Water (PSW). The SSL was observed primarily in the uppermost 100. m of the PSW, which provided a desirable habitat for Arctic copepods due to high nutrients and phytoplankton biomass. The highest density SSL was observed in the eddy-like structure of the PSW, which is most likely because of the high nutrients and chl-a. High regional densities in the SSL indicated that Arctic copepods provide a large portion of the biomass and contribution to the food webs in the PSW, in the western Arctic Ocean. © 2015 Elsevier Ltd.
Jang D.-J.,Chonnam National University |
Kim T.-H.,Chonnam National University |
Na S.-C.,Korea Marine Environment Management Corporation
Sea Technology | Year: 2012
Marine accidents such as ship collision and stranding or careless handling of oil can cause spills, leading to marine pollution. A large-scale spill involving a big ship such as the Hebel Spirit, which spilled approximately 10,000 tons of crude oil from a collision in South Korea's Taean Coast in December 2007, could widely contaminate nearby coasts in a short time. The oil recovery efficiency of the designed system is limited to the truck's tank capacity. The skimmer must have a high pure-oil recovery rate, with low water content. This system applies a disk- type oil skimmer, with multiple disks arranged vertically in a narrow space. The factors influencing the performance of disk-type skimmers are the kind of oil, viscosity, thickness, disk width, number of disk rotations and disk material. With the same oil characteristics and disk operation conditions, disk material may decide the recovery rate.
Sato-Okoshi W.,Tohoku University |
Okoshi K.,Toho University |
Koh B.-S.,Korea Marine Environment Management Corporation |
Kim Y.-H.,B and G Eco Technology Environmental Monitoring Research Institute |
Hong J.-S.,Inha University
Aquaculture | Year: 2012
Polydorid species (Polychaeta: Spionidae) are widely known for their boring activities in mollusk shells and they often become harmful invaders. A total of seven species of the genera . Polydora, Dipolydora, and . Boccardiella were collected and described from wild and cultured mollusk shells from the intertidal to subtidal for the first time in Korean waters. The most common species observed to bore shells were . Polydora haswelli and . Polydora aura. . Polydora haswelli is recorded for the first time in Asian waters. Wild and cultured abalone . Haliotis discus discus, wild . Atrina pectinata, and cultured oyster . Crassostrea gigas were heavily infested by . P. haswelli and . P. aura. . Polydora uncinata was very abundant only from the cultured oyster . C. gigas from southeastern Korea, indicating that this species may have been transported with a different oyster population introduced to the area. . Polydora limicola inhabited mud deposits in crevices of wild . Chlamys farreri shells and caused severe damage to them. Small sized . Dipolydora giardi and . Dipolydora alborectalis were extracted only from wild shells. . Boccardiella hamata was common associated with wild . C. gigas in mud flats. We discuss the polydorid species from the viewpoint of aquaculture and unintentional transportation of alien species which have been introduced with commercially important host shells. © 2012 Elsevier B.V.
Nam J.,Korea Maritime Institute |
Son K.-H.,Korea Marine Environment Management Corporation |
Khim J.S.,Seoul National University
Ocean and Polar Research | Year: 2015
Korean society has been recently promoting the restoration of coastal wetlands. These efforts might become the basis of a policy framework that compensates for the limitations of a regulation-oriented policy such as the designation of Marine Protected Areas (MPAs). The shift in government policy could contribute to strengthening the socioeconomic infrastructure of coastal development through the accumulation of ecological capital. Although our scientific efforts and social demands in regard to the ecological restoration of the coastal wetlands have increased during the past years, the bases for restoration in Korea requires that scientific, technological, financial, social and legal aspects be enhanced. The present study re-examined the concept and attitudes behind coastal wetland restoration in the light of changing circumstances in Korea. Herein, we first defined coastal wetland restoration as “An act of recovering the functions of the ecosystem of coastal wetlands to a state that resembles conditions prior to being damaged.” Next, this study discussed the limitations and future directions of such restoration efforts based on the descriptive analyses of recent restoration practices from social, economic, and technological aspects. Finally, we suggest future policy directions regarding coastal wetland restoration on the basis of a PFST (Policy, Financial, Social, and Technological) analysis; 1) re-arranging legal mechanisms, 2) setting multidimensional restoration goals, 3) establishing a multi-discipline-and convergence based R&D system, 4) linking spatial management and local development to the restoration, 5) building restoration governance at the local level, 6) implementing an ecosystem service payment system, and 7) applying test-bed projects in accordance with proper directions. © 2015 Korea Ocean Research and Development Institute. All rights reserved.
Lee H.-G.,National Oceanic and Atmospheric Administration |
Yoon K.-T.,National Oceanic and Atmospheric Administration |
Park H.-S.,Korea Marine Environment Management Corporation |
Hong J.-S.,Inha University |
Lee J.-H.,National Oceanic and Atmospheric Administration
Ocean and Polar Research | Year: 2016
This study examined the relationship between macrobenthic distribution patterns and environmental factors in salt marsh vegetation in Donggeomdo, Ganghwa on the west coast of Korea. Nine stations were fixed on a transect across the salt marsh vegetation, and field sampling was carried out monthly from July 1997 to June 1998. A total of 38 species of macrobenthos were recorded: each of faunal groups, 13 (34.2%) Arthropoda, 12 (31.6%) Polychaeta, 8 (21.1%) Mollusca, and 5 (13.2%) others. The mean density was 2,659 individuals/m2, with a mean biomass of 178.6 gWWt/m2. Mollusca dominated in terms of abundance and biomass, with a mean density of 2,172 individuals/m2 (81.7%) and a mean biomass of 131.9 gWWt/m2 (73.9%). The number of species decreased in winter (January-February), while mean density increased in the spring (May-June). The biomass was relatively in Summer and Fall (July-November), than any other season. The number of species was high in pure stands of Suaeda japonica in the lower salt marsh vegetation, and the mean density and biomass were high in mixed halophyte communities in the middle salt marsh vegetation. Two Mollusca, the bivalve Glauconome chinensis and gastropod Assiminea lutea, were dominant. The densities of these two species were high in mixed halophyte communities in the middle salt marsh vegetation. Non-metric multi-dimensional scaling (nMDS) showed that the study area could be divided into four groups corresponding to the vertical distribution of tidal levels and halophytes. Spearman’s rank correlation revealed that the distribution patterns and community structure of macrobenthos were related to environment variables such as salinity of the substrates, exposure time, and grain size compositions of the sediment in the salt marsh vegetation. Particularly, the distribution and density of some dominant species showed differences along the vertical distributions of halophytes. © 2016, Korea Ocean Research and Development Institute. All rights reserved.
Lee S.H.,Pusan National University |
Kim B.K.,Pusan National University |
Yun M.S.,Pusan National University |
Joo H.,Pusan National University |
And 4 more authors.
Polar Biology | Year: 2012
To date, no direct measurements of primary production were taken in the Amundsen Sea, which is one of the highest primary productivity regions in the Antarctic. Phytoplankton carbon and nitrogen uptake experiments were conducted at 16 selected stations using a 13C- 15N dual isotope tracer technique. We found no statistically significant depletions of major inorganic nutrients (nitrate + nitrite, ammonium, and silicate) although the concentrations of these nutrients were markedly reduced in the surface layer of the polynya stations where large celled phytoplankton (>20 μm) predominated (ca. 64 %). The average chl-a concentration was significantly higher at polynya stations than at non-polynya stations (p < 0.01). Average daily carbon and nitrogen uptake rates by phytoplankton at polynya stations were 2.2 g C m -2 day -1 (SD = ±1.4 g C m -2 day -1) and 0.9 g N m -2 day -1 (SD = ±0.2 g N m -2 day -1), respectively, about 5-10 times higher than those at non-polynya stations. These ranges are as high as those in the Ross Sea, which has the highest productivity among polynyas in the Antarctic Ocean. The unique productivity patterns in the Amundsen Sea are likely due to differences in iron limitation, phytoplankton productivity, the timing of phytoplankton growing season, or a combination of these factors. © 2012 Springer-Verlag.
Hwang D.-W.,National Institute of Fisheries Science |
Kim S.-G.,Korea Marine Environment Management Corporation |
Choi M.,National Institute of Fisheries Science |
Lee I.-S.,National Institute of Fisheries Science |
And 2 more authors.
Marine Pollution Bulletin | Year: 2016
Spatial distributions and temporal variations of trace metals in Korean coastal sediments were investigated by determining seven metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) in sediment collected from 71 stations between 2004 and 2010 (n = 491). High metal concentrations were found in the southeastern coast, where there are many cities and industrial complexes, indicating that metal concentrations in Korean coastal sediment are significantly influenced by human activities associated with urbanization and industrialization. However, metal concentrations in sediment did not markedly vary temporally, which was because the coast is managed sustainably and because of the characteristics of the sediment environments. Based on the sediment quality guidelines and geoaccumulation index, Korean coastal sediments are practically unpolluted with Cd, Cr, Cu, Hg, Pb and Zn but moderately polluted with As. More intensive monitoring is required to determine the potential As sources and to understand the As geochemical cycles in Korean coastal sediments. © 2015 Elsevier Ltd.
Kim M.-S.,Inha University |
Kim M.-S.,Korea Marine Environment Management Corporation |
Jung J.-H.,Inha University |
Min G.-S.,Inha University
Journal of Crustacean Biology | Year: 2013
To date, the genus Platorchestia Bousfield, 1982 (Crustacea, Amphipoda) includes 17 species, all of which are adapted to terrestrial and supra-littoral habitats. According to a recent study, some species exist as cryptic species complexes. Here, we describe a new beachhopper, Platorchestia parapacifica, collected from beaches in South Korea. This new species can be easily distinguished from other congeners by the morphology of its antennae 1 and 2, gnathopods, coxal plate 6, pereiopod 7, and telson. We detail the morphological characteristics of P. parapacifica, and compare it with related species. In addition, we demonstrate the phylogenetic relationships of the genus Platorchestia based on the mitochondrial cytochrome c oxidase subunit 1. The results of our molecular analyses indicate that the P. platensis-complex is monophyletic and deeply divergent from the P. japonica-complex. Estimation of the genus divergence times using molecular clock analysis suggests that these species shared a most recent common ancestor during the Miocene period (7.9-10.5 million years ago). Notably, common ancestry of the P. japonica complex diverged into two species during the Zanclean and Messinian periods (3.7-6.6 million years ago), while the ancestral talitrid of the P. platensis complex diverged into three species during the Messinian and Tortonian period (6-8 million years ago). Our results reconfirm the usefulness of molecular techniques for biodiversity studies of talitrids, including phylogenetic relationships, species boundaries, and divergence times. © The Crustacean Society, 2013.
Jiang Y.,Ocean University of China |
Jiang Y.,Korea Polar Research Institute |
Yang E.J.,Korea Polar Research Institute |
Kim S.Y.,Marine Biodiversity Institute of Korea |
And 2 more authors.
Progress in Oceanography | Year: 2014
To investigate the impacts of climate change on environmental conditions and pelagic biodiversity, spatial patterns in pelagic ciliate communities were studied at 18 stations from five habitats in the Amundsen Sea (western Antarctic) during austral summer from December 2010 to January 2011. Clear spatial patterns were observed in community structure, and significant differences were found among the various habitats. The species number, abundance, biomass and biodiversity indices (Shannon diversity H', Pielou's evenness J', and Margalef richness D) also showed clear spatial trends. Pelagic ciliate community structure accurately reflected environmental variability. Alone or in combination, several primary environmental variables were found to affect community spatial patterns in specific habitats. Shannon H' and Margalef D showed strong relationships with spatial changes in chlorophyll a and might be better predictors in future Antarctic studies. This study presents the first detailed description of spatial patterns in pelagic ciliate communities and their correlations with environmental variability in habitats in the Amundsen Sea during early austral summer. Our findings provide detailed and basic data on the composition, distribution, and variation of ciliate communities in the Amundsen Sea, and will help answer important questions about polar ecosystems. © 2014 Elsevier Ltd.
PubMed | Korea Marine Environment Management Corporation and National Institute of Fisheries Science
Type: Journal Article | Journal: Marine pollution bulletin | Year: 2016
Spatial distributions and temporal variations of trace metals in Korean coastal sediments were investigated by determining seven metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) in sediment collected from 71 stations between 2004 and 2010 (n=491). High metal concentrations were found in the southeastern coast, where there are many cities and industrial complexes, indicating that metal concentrations in Korean coastal sediment are significantly influenced by human activities associated with urbanization and industrialization. However, metal concentrations in sediment did not markedly vary temporally, which was because the coast is managed sustainably and because of the characteristics of the sediment environments. Based on the sediment quality guidelines and geoaccumulation index, Korean coastal sediments are practically unpolluted with Cd, Cr, Cu, Hg, Pb and Zn but moderately polluted with As. More intensive monitoring is required to determine the potential As sources and to understand the As geochemical cycles in Korean coastal sediments.