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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.

Hahm D.,Korea Polar Research Institute | Rhee T.S.,Korea Polar Research Institute | Kim H.-C.,National Oceanic and Atmospheric Administration | Park J.,Korea Polar Research Institute | And 4 more authors.
Journal of Geophysical Research: Oceans | Year: 2014

We observed ΔO2/Ar in the surface waters of the Amundsen Sea, Antarctica, during the austral summers in 2011 and 2012 to investigate the variability of net community production (NCP). Corresponding to the typical peak phytoplankton bloom period, the ΔO2/Ar of the Amundsen Sea Polynya (ASP) reached 30% in early January 2011 and had a strong positive correlation with the sea surface temperature (SST) and chlorophyll-a (Chl-a). In contrast, ΔO2/Ar decreased to -10% in the sea ice zone (SIZ), which was likely associated with either net O2 consumption in the unlit area or the entrainment of deep water containing low dissolved oxygen. Near the terminal stage of the phytoplankton bloom in late February 2012, we observed the same contrasting ΔO2/Ar features between the ASP and SIZ. However, the ΔO2/Ar in the ASP was not >10%, which corresponded with the overall reduction in Chl-a, solar radiation, and SST compared with the corresponding values in 2011. The average net community production in the ASP was 119 ± 79 mmol O2 m-2 d-1 in January 2011, and 23 ± 14 mmol O2 m -2 d-1 in February 2012. The strong correlations of NCP with SST and mixed layer depth (MLD) indicate that the ASP phytoplankton bloom is likely initiated by a combination of increased light availability and SST in early summer. Low SST and variable fluorescence to maximum florescence ratio (Fv/Fm) in February indicate that decreased solar radiation and Fe availability are likely responsible for the phytoplankton bloom demise. Key Points Significantly higher NCP in the polynyas than sea ice zones Strong temporal variation in NCP between January and February The variation is due to the combined effect of SST, light, and Fe availabilities © 2014. American Geophysical Union. All Rights Reserved.

Gwak Y.-S.,Pusan National University | Kim S.-H.,Pusan National University | Lee Y.-W.,Pusan National University | Lee Y.-W.,Korea Marine Environment Management Corporation | And 3 more authors.
Hydrological Processes | Year: 2014

Submarine groundwater discharges (SGD) were investigated in a marine watershed in south-eastern Korea using water budget analysis and a 222Rn mass balance model. Multi-layered TOPMODEL added hydrological assumption was used to estimate groundwater components in the water budget analysis. Field observations of soil moisture, rainfall, runoff and groundwater fluctuations were used for calibration and validation of the hydrologic model. Based on observed hydrological data and terrain analyses, parameters for the hydrologic model were delineated and used to describe several hydrologic responses in the watershed. SGD estimations by 222Rn mass balance method were also performed at Il-Gwang bay in July, 2010, and May, June, July and Nov. 2011. The estimated groundwater through hydrologic modeling and water balance analysis was 1.3x106 m3/year, which rapidly increased during typhoon season due to heavy rainfall and permeable geologic structure. The estimated groundwater was approximately 3.7-27.1% of SGD as evaluated by 222Rn mass balance method ranges 3.44 and 17.45 m3m-2year-1. Even though SGD is predominantly influenced by tide fluctuation, the head gradient (difference) from hydrologic processes associated with heavy rainfalls can also have extra significant influences. Comprehensive understanding of SGD evaluation can be improved through a simultaneous application of both these approaches. © 2013 John Wiley & Sons, Ltd.

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.

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