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Koo B.J.,Marine Ecosystem Research Division | Koh C.-H.,Seoul National University
Ocean Science Journal | Year: 2013

Macrofaunal burrows increase the surface area of the sediment-water interface, which has a great impact on the metabolism of aerobic microbes and the oscillation of reduced metabolites within the sediment. Given the importance of macrofauna in surficial sediments, the aim of this study is to examine the effects of burrow architectures on dissolved oxygen diffusion rates in comparison with unburrowed sediment, and thereby to evaluate the theoretical assumption used for modeling solute distribution in the burrow system using field samples. Employing microsensors, horizontal oxygen profiles were measured on a micrometer scale around burrows of seven invertebrates in tidal flats of the west coast of Korea. Oxygen diffusion distance through the burrow walls of seven invertebrates showed spatio-temporal variation with a range of 0.6 to 2.9 mm. Two groups of burrows were identified based on their oxygen diffusive properties relative to unburrowed sediments: 1) oxygen penetration similar to that of ambient sediments and 2) clearly enhanced oxygen penetration. Differences in the diffusive properties of the burrow wall were related to the burrow depth and diameter, existence of mucus lining on the wall, sediment grain size, and tidal phases. Also inhabitant activity was an important factor affecting oxygen penetration, which is discussed in the paper. These results further demonstrate that simplified assumptions (i.e. burrow structures are viewed as direct biogeochemical extensions of the sediment-water interface) may not be exact representation of the nature. © 2013 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht. Source


Zubrzycki I.Z.,Hanyang University | Lee S.,Hanyang University | Lee K.,Hanyang University | Lee K.,Marine Ecosystem Research Division | And 2 more authors.
Ocean Science Journal | Year: 2012

The objective of the study was to analyze constantlyhighly expressed proteins as a function of elevated midultraviolet (UVB, 280-315 nm) radiation in Tigriopus japonicus sensu lato (T. japonicus s. l). We also analyzed associations between kinetics of radiation avoidance, measured as a covered distance per time unit, and highly expressed proteins. The obtained results indicate an increase in T. japonicus s. l. mobility between the control (no radiation) and mild UV radiation levels (15 kJ·m -2). Two-dimensional gel electrophoresis combined with MALDI-MS-MS resulted in 2D protein map comprising of 686 protein spots, of which 19 were identified as highly expressed proteins across all experimental conditions. Obtained results indicate that calpain, vitellogenin, and collagenase are housekeeping protein that are expressed at a constant level independently of environmental changes and that adoption of a locomotive system for the avoidance of a UV source may be, at least partially, supported by hepatopancreas-driven metabolism. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Netherlands. Source


Kim Y.-O.,South Sea Research Institute | Shin K.,South Sea Research Institute | Jang P.-G.,South Sea Research Institute | Choi H.-W.,Oceanogaphic Data and Information Center | And 4 more authors.
Ocean Science Journal | Year: 2012

This study examined seasonal and annual occurrences of warm oceanic tintinnid species in southern Korea coastal waters. The indicative species of tintinnids was monitored using three approaches: monitoring from cruises traveling from the warm pool in the western North Pacific to the Korea Strait; biweekly or monthly monitoring in the Korea Strait; and daily monitoring in the nearshore water. Annual pulses of warm oceanic indicator species were regularly observed in the Korea Strait. In September 2008 recorded a maximum species number of warm water indicators, a representative species for warm oceanic waters, Climacocylis scalaroides was simultaneously detected in the nearshore water as well as the Korea Strait. The result indicates that the greater warm water extension into Korean coastal areas was in September 2008. Sharp declines in species diversity were observed in the transitional area between neritic and Kuroshio zone in East China Sea (ECS). Epiplocyloides reticulata, reported previously as a Kuroshio indicator, was considered an ECS indicator species, as it was undetected in the western North Pacific central zone but was found abundantly in the ECS. Tintinnid species can be used as biological indicators to detect the inflow of warm oceanic waters into Korean coastal waters. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht. Source


Hwang S.-W.,Marine Ecosystem Research Division | Kang H.-K.,Marine Ecosystem Research Division | Son Y.-B.,Korea Ocean Satellite Center | Jang M.-C.,Ballast Water Center South Sea Institute | Choi K.-H.,Ballast Water Center South Sea Institute
Journal of Coastal Research | Year: 2013

The damming of major rivers can have broad impacts on ecological processes in adjacent marine ecosystems. Thirty years of sampling data from the northern East China Sea show that the recent impounding of water by the Three Gorges Dam on the Changjiang River (Yangtze River) might have had dramatic impacts on the mesozooplankton community. The reduction in freshwater discharge and subsequent increases in phytoplankton biomass have resulted in a substantial increase in total mesozooplankton wet weight but sharp declines in the abundance of all of the crustacean components. The increase in mesozooplankton biomass is probably associated with an increase in small, gelatinous zooplankton. Together with an increase in sea surface temperature in the region, the reduced freshwater and sediment discharge might have led to the proliferation of gelatinous mesozooplankton in this historically overfished region, generating significantly increased grazing pressure on planktonic crustaceans. © Coastal Education & Research Foundation 2013. Source


Yoon J.-E.,Marine Ecosystem Research Division | Yoon J.-E.,Daejeon University | Park J.,Korea Polar Research Institute | Yoo S.,Marine Ecosystem Research Division
Ocean Science Journal | Year: 2012

This study compares five primary productivity algorithms for Korean waters. Five algorithms are in the form of vertical generalized production models: One algorithm is for gross primary production and four are for net primary production. The five algorithms were evaluated using 117 in situ primary production datasets observed by 20 cruises from 1994 to 2011 in Korean waters (East Sea, Yellow Sea, East China Sea, and Yeosu Bay). The results show that the regionally-tuned variants give better results than the original formulation. We recommend, among the tested algorithms, YSVGPM (Yellow Sea Vertically Generalized Productivity Model) for gross primary productivity algorithm and Kameda-Ishizaka algorithm for net primary productivity algorithm for estimating primary production in Korean waters. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht. Source

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