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Kim S.-J.,Korea Research Institute of Bioscience and Biotechnology | Kim J.-H.,Korea Polar Research Institute | Ju S.-J.,Deep sea and Seabed Mineral Resources Research Center | Ju S.-J.,Korean University of Science and Technology
Ocean Science Journal | Year: 2017

Although the response unit of living organisms to environmental changes is at the individual level, most experiments on the adaptation responses of ciliates have been conducted in batches, comprising multiple-individuals, due to their microscopic size. However, here, we confirmed that individuals undergo different division cycles in monocultures of Euplotes crassus. They also exhibited transcript variations of 4.63-fold in SSU and of 22.78- fold in Hsp70. Additionally, in salt-stressed E. crassus individuals, SSU transcripts of individuals varied by 6.92-fold at 27 psu, 8.69- fold at 32 psu, and 2.51-fold at 37 psu. However, the maximum difference in Hsp70 was only 4.23-fold under all conditions. These results suggest there may be different biological rhythms even in siblings derived from the same parent. It can also be inferred that various environmental factors have different effects on different E. crassus individuals. Therefore, to elucidate relationships between organism adaptations and environmental changes, studies at the individual level should be conducted with multi-individual approaches. © 2017, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.


Kong G.S.,Korea Institute of Geoscience and Mineral Resources | Hyeong K.,Deep sea and Seabed Mineral Resources Research Center | Choi H.-S.,Korea Institute of Geoscience and Mineral Resources | Chi S.-B.,Deep sea and Seabed Mineral Resources Research Center
Ocean and Polar Research | Year: 2014

The benthic environmental impact experiment addresses environmental impacts at a specific site related to deep-sea mineral resource development. We have acquired several tens of multi- or box core samples at 31 sites within the Benthic environmental Impact Site (BIS) since 2010, aiming to examine the basic properties of surficial deep-sea sediment as a potential source for deep-water plumes. In this study, we present the geochemical properties such as major elements, rare earth elements (REEs), and heavy metal contents at the BIS. Such proxies vary distinctly according to the Facies association. The lithology of all core sediments in the BIS corresponds to both Association Ib and Association IIIb. The vertical profiles of some major elements (SiO2, Fe2O3, CaO, P2O5, MgO, MnO) show noticeable differences between Association Ib and IIIb, while others (Al2O3, TiO2, Na2O, and K2O) do not vary between Association Ib and IIIb. REEs are also distinctly different for Associations Ib and IIIb; in Association Ib, REY and HREE/LREE are uniform through the sediment section, while they increase downward in Association IIIb like the major elements; below a depth of 8 cm, REY is over 500 ppm. The metal enrichment factor (EF) evaluates the anthropogenic influences of some metals (Cu, Ni, Pb, Zn, and Cd) in marine sediments. In both Associations, the EF for Cu is over 1.5, the EF for Ni and Pb ranges from 0.5 to 1.5, and the EF for Zn and Cd are less than 0.5, indicating Cu is enriched but Zn and Cd are relatively depleted in the BIS. The vertical variations of geochemical properties between Association Ib and IIIb are shown to be clearly different, which seems to be related to the global climate changes such as the shift of Intertropical convergence zone (ITCZ). © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Kim W.,Deep sea and Seabed Mineral Resources Research Center | Hyeong K.,Deep sea and Seabed Mineral Resources Research Center | Kong G.S.,Korea Institute of Geoscience and Mineral Resources
Ocean and Polar Research | Year: 2014

A 570 cm-long sediment core was retrieved at 9o57'N and 131o42'W in 5,080 m water depth from the northeast equatorial Pacific and its stratigraphy was established with10Be/9Be and paleomagnetic measurements. Successive AF demagnetization reveals eight geomagnetic field reversals. In the reference geologic time scale, the eight reversal events correspond to an age of about 4.5 Ma. However,10Be/9Be-based age yields 9.5 Ma at a depth of 372 cm. Such a large discrepancy in determined ages is attributed to an extremely low sedimentation rate, 0.4 mm/kyr on average, of the study core and resultant loss or smoothing of geomagnetic fields. The composite age model reveals a wide range in the sedimentation rate - varying from 0.1 to 2.4 mm/kyr. However, the sedimentation rate shows systematic variation depending on sedimentary facies (Unit II and III), which suggests that each lithologic unit has a unique provenance and transport mechanism. At depths of 110-80 cm with a sedimentation rate of about 0.1 mm/kyr, ancient geomagnetic field reversal events of at least a 1.8 Myr time span have not been recorded, which indicates the probable existence of a hiatus in the interval. Such a sedimentary hiatus is observed widely in the deep-sea sediments of the NE equatorial Pacific. © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Yu O.H.,KIOST | Son J.W.,Deep Sea and Seabed Mineral Resources Research Center | Ham D.J.,Deep Sea and Seabed Mineral Resources Research Center | Lee G.C.,Deep Sea and Seabed Mineral Resources Research Center | Kim K.H.,Deep Sea and Seabed Mineral Resources Research Center
Ocean and Polar Research | Year: 2014

In August, 2013, we collected epifaunal megabenthos using a deep sea camera (DSC) around a benthic impact study (BIS) site. This was located in the KR5 block of the Korea Deep Ocean Study (KODOS) area in the Northeastern Pacific. The DSC was positioned at 6.8 ± 2.9 m (SD) from the sea bottom and was operated from a position at 131o56.85' - 131o55.02'W for 2.3 h at a speed of 1-2 knot. The geographical features of the study area consisted of two structures; a trough in the middle and hills at the east and west sides. Sediment conditions were consistent within six blocks and were affected by slope and polymetallic nodule deposits. We analyzed 226 megafaunal species. Sipunculida comprised the highest percentage of individuals (39%), and the dominant epifaunal megabenthos were Hormathiidae sp., Primnoidae sp., Hexactinellida sp., Hyphalaster inermis, Freyella benthophila, Paelopatides confundens, Psychropotes longicauda, and Peniagone leander. More than 80% of the total density of megafauna occurred on sea plain (D- and E-blocks). We found two distinct groups in the community, one located on sea plains and the other along both sides of the sea slop. Our results suggest that geographical features such as slope and polymetalic nodule deposits are important in controlling the distribution of the epifaunal megabenthos around the KODOS area. © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Yoon H.,Deep sea and Seabed Mineral Resources Research Center | Yoon H.,Inha University | Ko A.-R.,Seoul National University | Kang J.-H.,South Sea Environment Research Center | And 3 more authors.
Ocean and Polar Research | Year: 2016

To understand the diet of chaetognaths, the gut content and fatty acid trophic makers (FATMs) of Sagitta crassa and S. nagae, which are the most predominant species of chaetognath in the Yellow Sea, were analyzed. Gut contents of the two species examined by microscopic analysis revealed that copepods are the major components of the diet (> 70% of gut contents) and there was no significant changes in the gut contents of two species collected in spring and summer season. Although 16:0, 20:5(n-3) (Eicosapentaenoic acid) and 22:6(n-3) (Docosahexanoic acid), which are known as phytoplankton FA markers, were the most dominant among the fatty acids in both chaetognath species, the detection of copepod FA markers, 20:1(n-9) (Gadoleic acid) and 22:1(n-11) (Cetoleic acid), provided evidence that their food sources include copepods. These results suggest that S. crassa and S. nagae are carnivores and mainly feed on copepods in the Yellow Sea. © 2016, Korea Ocean Research and Development Institute. All rights reserved.


Chi S.B.,Deep sea and Seabed Mineral Resources Research Center | Hong S.,Korea Research Institute of Ships and Ocean Engineering
Ocean and Polar Research | Year: 2014

In early 1990s, the Korean government has launched a deep-sea research program to secure the stable long-term supply of strategic metallic minerals including Cr, Cu and Ni. Through the pioneering surveys, Korea registered 150,000 km2 of Mn-nodule field in the Clarion-Clipperton area, the NE equatorial Pacific to the international sea-bed authority (ISA) in 1994. Following the ISA exploration code, the final exclusive exploration area of 75,000 km2 was assigned in 2002, based on results of eight-year researches of chemical-physical properties of nodules, bottom profiles and sediment properties. Since that time, environmental studies, mining technical developments including robot miner and lifting system and establishment of smelting systems were accompanied with the detailed geophysical studies to decipher the priori mining area until 2009. Major points of the recent Korea Mn-nodule program are deployed on a commercial scale until 2015. In order to meet the goals, we developed a 1/5 scaled robot miner compared to commercial one in 2012 and performed a mining test at the water depth of 1,370 m in 2013. In addition, detailed 25,000 scaled mining maps in the priori area, which can provide operation roots of the miner, will be prepared and an environmental-friendly mining strategy will be pursued based on the environmental impact test and environmental monitoring. © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Lee P.-M.,Marine Robotics Laboratory | Jun B.-H.,Marine Robotics Laboratory | Lee P.-Y.,Hanwha Co. | Kim W.-S.,Deep sea and Seabed Mineral Resources Research Center | Yu S.-C.,Creative IT
MTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World | Year: 2015

This paper presents the recent R&D activities on underwater vehicles in Korea. A highly maneuverable high speed ROV has been developed for surveying the strong tidal area. Characteristics of the vehicle are discussed in view of flow effect and operation at strong currents. This paper introduces a high speed AUV HW200 and discusses its operational test at high speed conditions. This paper present a seabed walking robot CR200 and its activities, which was conducted to capture a scanning image of the sunken ferry Sewol and to identify the seabed objects last year. A hovering-type UUV Cyclops with acoustic image recognition is introduced as well. Finally this paper presents a plan for the development of a manned submersible in Korea. © 2015 IEEE.


Kim W.,Deep sea and Seabed Mineral Resources Research Center | Yang S.J.,Deep sea and Seabed Mineral Resources Research Center | Chi S.-B.,Deep sea and Seabed Mineral Resources Research Center | Lee H.-B.,South Sea Research Institute
Ocean and Polar Research | Year: 2014

Korea contract Mn-nodule field in the NE equatorial Pacific is composed of seven sectors with average water depths of 4,513-5,025 m. Of the various factors controlling the properties of Mn-nodule, it seems that water depth is likely connected to the chemical composition and occurrence of nodules. To test whether such an assumption held in each sector, we reviewed previous research data accumulated since 1994 for one of the northern sectors (hereafter KR1) where there are stark contrasts in water depth. High-resolution seabed mapping clearly separates a northern part (KR1N) from a deeper southern part (KR1S), cutting across in the middle of the KR1. In addition, significant volcanic activities forming numerous seamounts are distinctive especially in KR1N. In terms of nodule occurrence, manganese nodules in KR1S are comparatively larger (2-4 cm) with a discoidal shape, while those in KR1N are generally small (<2 cm) with poly-lobate and irregular shapes. Nodules in KR1N also have lower Co, Cu, Mn and Ni, and higher Fe contents. The spatial separation in nodule characteristics might be caused by volcanic activities in KR1N rather than water depth contrast. During the formation of the seamounts in KR1N, rock fragments and volcanic ashes as new nuclei of the nodules would have been continuously generated. As a result, the nodules could not grow larger than 2 cm and display the shapes of a newbie (i.e., irregular and poly-lobate shapes). Moreover, significant Fe supply from volcanic activities probably decreases the Mn/Fe ratio, which may lead to the KR1 nodules being misinterpreted as a hydrogenic in origin compared to other sectors where a high Mn/Fe ratio is present. © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Lee H.-B.,South Sea Research Institute | Kim W.,Deep sea and Seabed Mineral Resources Research Center | Ko Y.-T.,Deep sea and Seabed Mineral Resources Research Center | Oh J.-R.,South Sea Research Institute | Chi S.-B.,Deep sea and Seabed Mineral Resources Research Center
Ocean and Polar Research | Year: 2014

The Korea Institute of Ocean Science and Technology has acquired detailed biological, chemico-physical, and geological data in the northeastern Pacific through a manganese nodule program since 1983. Plenty of manganese nodules were collected to estimate the amount of resources by free-fall grab and box corer. The collected manganese nodules have been archived systematically in the rock and mineral storage section of the Library of Marine Samples (LIMS) since 2012. The LIMS provides essencial information on the stored samples including sample name, nodule type, sampling location, depth, and equipment. Although a high quality database of the information system is under construction, the samples have tagged information for manganese nodules like chemical composition, morphology, weight, size, abundance, and photograph. In this study, we attempted to provide information on the well-organized and easily accessible archived manganese nodule samples for future studies and to introduce the usefulness of the LIMS. © 2014, Korea Ocean Research and Development Institute. All rights reserved.


Son J.,Deep sea and Seabed Mineral Resources Research Center | Kim K.H.,Deep sea and Seabed Mineral Resources Research Center | Kim H.J.,Deep sea and Seabed Mineral Resources Research Center | Ju S.-J.,Deep sea and Seabed Mineral Resources Research Center | Yoo C.M.,Deep sea and Seabed Mineral Resources Research Center
Ocean and Polar Research | Year: 2014

Verifying the similarity of environmental characteristics between an artificial impact site and a preserved or reference site is necessary to quantitatively and qualitatively evaluate the environmental impact of mining activity. Although an impact site (BIS station) and a preserved site (called KOMO station) that have been selected in the Korea manganese nodule contract area may share similar environmental characteristics, similarities in terms of the water column environment between both sites has not been investigated. In this study, we compared the chemical properties of the water columns and sinking particle fluxes between BIS and KOMO stations through two observations (August 2011 and September 2012). Additionally, we observed particle fluxes at the KOMO station for five years (July 2003 ~ July 2008) to understand long-term natural variability. Vertical distributions of water column properties such as dissolved oxygen, inorganic nutrients (N, P, Si), total organic carbon below surface layer (within the depth range of 200 m) were not considerably different between the two sites. Especially, values of water column parameters in the abyssopelagic zone from 4000 m to bottom layer (~5000 m) were very similar between the BIS and KOMO sites. Sinking particle fluxes from the two sites also showed similar seasonality. However, natural variation of particle flux at the KOMO site varied from 3.5 to 129.9 mg m-2 day-1, with a distinct temporal variation originating from ENSO events (almost forty times higher than a minimum value). These results could provide valuable information to more exactly evaluate the environmental impact of mining activity on water columns. © 2014, Korea Ocean Research and Development Institute. All rights reserved.

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