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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
The Korean Society of Oceanography
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Volume & Issues
Volume 4, Issue 4 - Nov 1999
Volume 4, Issue 3 - Aug 1999
Volume 4, Issue 2 - May 1999
Volume 4, Issue 1 - Feb 1999
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Physical Environment Changes in the Keum River Estuary by the Dyke Gate Operation: II. Salinity Structure and Estuary Type
Lee, Sang-Ho ; Kwon, Hyo-Keun ; Choi, Hyun-Yong ; Yang, Jae-Sam ; Choi, Jin-Yong ;
The Sea, volume 4, issue 4, 1999, Pages 255~265
CTD castings and current observations are taken in June, July and October, 1997 and May and July, 1998 to investigate the effect of the Keum River dyke on the structure of physical properties and the type of the Keum River estuary. Tide and tidal current relation shows that the ebbing is longer than the flooding by 1.5 hours with the early current reversing before high tide. In the rainy season (May to July), frequent large fresh water discharge during the ebbing from the dyke changes vertical salinity difference and time variation of salinity greatly near the head of the estuary, where salinity becomes lower than 2‰ in summer fresh water flooding. Halocline developed by the fresh water discharge makes two-layer structure, of which strength and depth increase in the low tide. The relationship between tide phase and surface salinity variation shows the phase lag of 2.5 hours near the head of the estuary but the standing wave relation down the estuary. This phase lag implies that a low salinity water diluted by the fresh water discharge for 2-3 hours in the ebb period moves with tidal excursion. In the dry season, vertical salinity difference reduces significantly. We calculate stratification and circulation parameters using the observed salinity structure, surface current and fresh water discharge. The Keum River estuary shows a partially mixed type, changing the stratification parameter from the rainy to the dry season. Mean flows of observed tidal current at lower and upper layer are landward and seaward, which are consistent with the circulation of a partially mixed estuary. Based upon the estuary type and circulation we suggest that the suspended materials will move toward the upstream due to low-layer mean flow and then the Keum River estuary will be a deposit environment.
Water Column Properties and Dispersal Pattern of Suspended Particulate Matter (SPM) of Marian Cove during Austral Summer, King George Island, West Antarctica
Yoo, Kyu-Cheul ; Yoon, Ho-Il ; Oh, Jae-Kyung ; Kim, Yea-Dong ; Kang, Cheon-Yun ;
The Sea, volume 4, issue 4, 1999, Pages 266~274
Vertical CTDT measurement at one point near tidewater glacier of fjord-head in Marian Cove, a tributary embayment of Maxwell Bay, South Shetland Islands was performed for 24 hours during the austral summer (January 21-22, 1998) to present water-column properties and SPM (suspended particulate matter) dispersal pattern in subpolar glaciomarine setting. Marian Cove shows three distinct water layers: 1) cold, freshened, and highly turbid surface plume in the upper 2 m, 2) warm, saline, and relatively clean Maxwell Bay water between 15-35 m in water depth, and 3) cold and turbid mid plume between 40-65 m in water depth. The surface plume is composed of silt-sized clastie particles mixed with flocculated biogenic detritus, and appears to originate from either supraglacial discharge by meltwater streams along the coast or water fall of ice cliff. Freshened and turbid mid plume consists exclusively of silt-sized clastic particles, resulting from subglacial discharge beneath the tidewater glacier. The disappearance of the two turbid plumes during the earlier period of measurement seems to be largely due to the breakup of the plumes by upwelling caused by strong easterly wind (> 8 m
). Thus, wind coupling over tidal effects regionally plays a major role in dispersal pattern of SPM as well as water exchange in Marian Cove.
Responses of Bacterial Production and Enzymatic Activities to Ocean-dumping of Organic Wastes in the Euphotic Zone of the East Sea, Korea
Song, Ki-Don ; Choi, Dong-Han ; Lee, Yoon ; Hong, Gi-Hoon ; Chung, Chang-Soo ; Kim, Suk-Hyun ; Cho, Byung-Cheol ;
The Sea, volume 4, issue 4, 1999, Pages 275~288
To understand the effects of ocean-dumping of organic wastes on bacteria, bacterial abundance and production, and hydrolytic activities of aminopeptidase (AMPase) and
-GLCase) were measured 5 times in the euphotic zone of the dumping and non-dumping areas of the East Sea from April 1996 to September 1997. Comparing the depth-integrated values of phytoplankton biomass and bacterial parameters over the euphotic zone of dumping area with those of non-dumping area, we found that activities of
-GLCase in the oceanic dumping area were always higher than those in the oceanic non-dumping area. Also, thymidine-based bacterial production always correlated significantly with leucine-based bacterial production in dumping area (balanced growth), but not in non-dumping area (unbalanced growth). These results seem to be bacterial responses to continuous dumping of organic matter into the dumping area. Further, a relationship between bacterial abundance and production was significant in dumping area, but insignificant in non-dumping area, indicating that control mechanisms of bacterial abundance were different in two areas. Relationships between other bacterial parameters varied with areas and seasons, suggesting that bacteria might be regulated by different factors in spring and summer. Further studies are required to test whether these seasonal variabilities of regulating factor are associated with changes in temperature, temperature-related phenomena, or characteristics of wastes.
Vertical Distribution and Composition of Dissolved Free Amino Acids in the Northeast Pacific Ocean
Son, Seung-Kyu ; Park, Yong-Chul ; Lee, Kyeong-Yong ; Kim, Ki-Hyune ; Lee, Hyo-Jin ;
The Sea, volume 4, issue 4, 1999, Pages 289~297
Concentrations of total dissolved free amino acids (DFAAs) in the northeast Pacific Ocean
) ranged from 15.9 to 1778.2 17M, and the average was 407.2 nM. Concentrations of DFAAs in surface mixed layers, ranged from 60.1 to 1411.9 nM, and the average was 535.2 nM. Seasonal thermoclines with maxima were formed between the depth of 50 to 150 m. DFAAs in this layer were varied in concentrations from 91.7 to 1778.2 nM, and the average was 588.5 nM. DFAAs below the seasonal thermoclines fluctuated from 15.9 to 384.2 nM, and the average was 175.1 nM. Consequently, in average relatively abundant DFAAs were observed in the subsurface layer than the deeper layer. DFAA vertical profiles and compositions of station A showed similar to station Band C. Glycine, alanine, glutamic acid, serine and valine were predominant accounting for more than 60% of total amino acids. Isoleucine, tyrosine, methionine and phenylalanine comprised only few percents of total DFAAs in the study area. In mole % of amino acid, according to characteristics of functional group of amino acid, aliphatic neutral accounted for 59% and aliphatic hydroxy 16%, acidic 12%, respectively. Although differences in DFAA concentrations with depth were observed, the amino acid composition and mole % of deeper layers in all stations were similar to those of subsurface layers. The results indicate that individual DtAAs remains invariably in water columns relative to the compositions and distributions of DFAAs in the study area, which may be the result of close coupling between microbial activity and their water solubility.
Study on Short-term Toxicological Evaluation of Treated Landfill Leachate Using Early Stage of River Puffer Fish, Takifugu obscurus
Park, Hoon ; Han, Kyung-Nam ; Kim, Hyung-Sun ;
The Sea, volume 4, issue 4, 1999, Pages 298~304
Toxic effect of landfill leachate on the larvae and juvenile stage of the river puffer fish, Takifugu obscurus, were investigated in order to assess severity of environmental impact of leachate effluent on the general population of estuarine fishes. A short-term toxic experiment was designed to test both laboratory hatched larvae and juveniles (5, 10 and 15 mm in length) and in-situ juveniles (30 and 45 mm in length) using the leachate concentrations between 0 and 16%. Lethal concentrations of 50% mortality (
) were observed using Spearman-karber Method. 24hr-
appeared at the leachate concentrations ranging from 3.03 to 8.57%, 48hr-
at 2.73 to 6.21 %, 72hr-
o at 2.45 to 5.53%, and 96hr-
at 2.38 to 4.93%, respectively. Leachate concentrations between 0.69 and 1.51% induced 96hr-
. Respiratory frequency was significantly affected even at low leachate concentrations between 0.5 and 1.0% (P < 0.05). These results suggest that the leachate effluents may cause a harmful impact on the physiology of river puffer fish, especially for younger cohorts.
Hydrographic Analysis of Surface Water Using Radium Isotopes Signature in the East and South China Sea in Summer
Yang, Han-Soeb ; Lee, Tong-Sup ;
The Sea, volume 4, issue 4, 1999, Pages 305~311
This study aims to decipher surface water mass interaction in summer in the South China Sea and East China Sea by radium isotope distribution pattern. Salinity and activity ratio of radium (
) showed gradual changes, which were adequate to apply simple two end-member mixing between Kuroshio surface water and Changjiang Dilute Water for the East China Sea and the former and Nearshore Diluted Watermass (NDW) for the South China Sea. Two tracer methods, salinity and Ra isotope ratio, were compared for East China Sea. Results showed remarkable consistency for waters near Kuroshio, however, discrepancy were noticeable after Tsushima Warm Current branching. Mixing with subsurface waters may cause the discrepancy. When mixed with subsurface waters, salts and radium isotope ratio are expected to be biased in opposite direction, i. e. prone to underestimate the fraction of less saline water in the case of salts and vice versa for Ra isotope ratio. Taking the mean values of two different results seems more realistic to estimate fraction of end-members.
Sediment Characteristics of Waste Disposal Sites in the Southwestern UUeung Basin, the East Sea
Chun, Jong-Hwa ; Huh, Sik ; Han, Sang-Joon ; Shin, Dong-Hyeok ; Cheong, Dae-Kyo ; Hong, Ki-Hoon ; Kim, Suk-Hyun ;
The Sea, volume 4, issue 4, 1999, Pages 312~322
We have studied both submarine morphology and sediment characteristics of waste disposal sites in the southwestern Ulleung Basin, East Sea, as part of a marine environmental preservation program. The Jung waste disposal site in the outer shelf is characterized by the thick accumulation of coarse-grained palimpsest sediments and fine-grained sediments from various sources. The Byung waste disposal site in the continental slope is generally characterized by hemipelagic muds with intermittent sandy sediments originated from the outer shelf and upper slope. The hemipelagic sediments, draping the seafloor, consist of fluidized muds. The core sediments show numerous bioturbation structures which cause vertical mixing of sediments. The surface sediments can be divided into four sand types (S-1, S-2, S-3, and S-4) and two mud types (M-1 and M-2) based on relative contents of reworked coarse-grained palimpsest sediments and fine-grained sediments. sorting and heavy mineral contents. The sands are probably relict sediments reworked during high-energy conditions such as typoon or storm. On the other hand, the muds were originated from various sources such as recent input from the Nakdong River, reworked fine-grained sediment from the shelf or suspended particulate matter from the East Sea Warm Current.
Characteristics of Seafloor Morphology and Manganese Nodule Occurrence in the KODES area, NE Equatorial Pacific
Jung, Hoi-Soo ; Ko, Young-Tak ; Chi, Sang-Bum ; Kim, Hyun-Sub ; Moon, Jai-Woon ;
The Sea, volume 4, issue 4, 1999, Pages 323~337
Seafloor morphology and manganese nodule occurrence were studied in the Korea Deep-sea Environmental Study (KODES) area, northeast equatorial Pacific, to understand their relationship. Study area is composed of three elongated valleys and hills with about 100~200 m height along NNE-SSW direction. Valley region is generally flat. However, hill region is very rugged with big cliffs of about 100m height and small depressions of several tens of meters depth. Tectonic movement along the Clarion-Clipperton fracture zone, consequent formation of elongated abyssal hills and Valleys, erosion of siliceous bottom sediments by bottom currents, and dissolution of carbonate sediments on the abyssal hills below CCD result in the rugged morphology. Manganese nodule occurrence is closely related to the morphology of the study area; mostly rounded-shaped manganese nodules with about 5 cm diameter are abundant on the flat valley region, whereas irregular shaped nodules (or manganese crust) with less than 5 cm to about 1 m diameter occur on the hill. These results supports the previous reports that nodule abundance, composition, and morphology are variable both on regional and local small scales on the seafloor even within some abundant nodule provinces depending on oceanographic characteristics such as bathymetric features, surface sediment type, sediment thickness, and so on. We suggest that such oceanographic characteristics affect interrelatedly on the formation of manganese nodules, and tectonic movement of the Pacific plate ultimately constrain the nodule occurrence. A potential mining place in the KODES area seems to be the valley region, which is elongated to the NNW-SSE direction with 3-4 km width.
Physical Properties of Mudbelt Sediments in the Southeastern Inner Shelf of Korea
Kim, Gil-Young ; Kim, Dae-Choul ; Seo, Young-Kyo ; Park, Soo-Chul ; Choi, Jin-Hyuk ; Kim, Jeong-Chang ;
The Sea, volume 4, issue 4, 1999, Pages 338~348
Physical properties of mudbelt sediments in the southeastern inner shelf of Korea are studied from 14 cores. Physical properties, compressional wave velocity, and sediment texture for core sediments are analyzed. The major source of sediment in the study area is the Nakdong River. Fine-grained sediments from the river are transported northeastward by coastal circulation and the Tsushima Current, resulting in a gradual northeastward increase in porosity and a decrease in wet bulk density and velocity. The trend matches well with the bathymetry. The mean grain size appears to be the most important variable to determine the physical properties and velocity. The variations of physical properties with burial depth are dependent more strongly on sediment texture than compaction and/or consolidation. Correlations between the physical properties and the sediment texture show slight deviations from those of the continental terrace sediment in the North Pacific and inner shelf sediment in the South Sea of Korea. The velocity is higher than that of the North Pacific and the South Sea sediments between these areas. This is probably due to differences in sedimentary, environment and mineral compositions. The higher sediment velocity in the study area may also be attributed to the escape of gas from pore space which decreases void ratio.
The Effects of Protozoa on the Early Formation of Microbial Fouling Communities of Inchon Coastal Waters
Choi, Joong-Ki ; Yang, Eun-Jin ; Lee, Won-Je ; Yoon, Won-Duk ; Shim, Jae-Hyung ;
The Sea, volume 4, issue 4, 1999, Pages 349~362
To understand the role of protozoa in the early formation of microbial fouling community, the studies on the formation of microbial film, the succession of microbial fouling communities, and the grazing pressure on bacteria population in microbial film were carried out in the laboratory, Inchon outer port and Inchon inner harbour. Bacteria and heterotrophic flagellates formed primary microbial film on the aluminum surface within 6 hours and oligotrich ciliates were observed 2 cells
on the same surface at 9 hours in Inchon inner harbour which had physically stagnant condition. The larvaes of Balanus albicostatus which were dominant meiobenthos in Inchon coastal area attached on the glass surface at the first day of experiment. Heterotrophic flagellates showed maximum abundance of 465 cells
at the 13rd day and ciliates showed maximum abundance of 63 cells
at the 11st day in the Inchon inner harbour. In the Inchon outer port which opens to the outer sea, the maximum abundance of protozoa occurred at early phase, but not so many. The dominant heterotrophic flagellates were Metrornonas simplex and Bodonids. Dominant ciliates were small tintinnids and oligotrich ciliate Strombidium sp., Large Strombidium (oligotrich ciliate) and sessile Acineta turberosa (suctorian ciliate) occurred after 10 days. The attached larvae of Balanus occurred as biofouling organism on the early surface and showed maximum abundance of 18 indiv.
at 7th day. At that time, adult barnacles were observed on the surface and dead barnacles were observed after two days. Except barnacles, the larvaes of Anthozoa sp., Oysters (Crassostrea gigas) and Polychaeta were observed on the surface from 3rd day. 3 benthic copepods including Harpacticus sp., I isopod, 1 polychaeta and 1 gastropoda were observed as predators of the microbial film on the surface after 7 days when microbial film developed very well. Although the ingestion rates of protozoa on the bactctia of the rnicrobi31 film were relatively low, the average grazing rate of protozoa on bacteria was high of 0.058
. This implied that the grazing pressure of protozoa influences the mortality of bacteria populations on the microbial film. but protozoa cannot get enough energy from only bacteria on the microbial film.
Comparison of the Morphological Characteristics and the 24S rRNA Sequences of Cochlodinium polykrikoides and Gyrodinium impudicum
Park, Jong-Gyu ; Park, Young-Shik ;
The Sea, volume 4, issue 4, 1999, Pages 363~370
When the first red tide alert by Cochlodinium polykrikoides was alarmed around the Oenarodo coast on Aug. 27, 1997, there co-occurred two chain-forming naked dinoflagellates which were different sized but looked fairly similar. The analyses of 24S rRNA sequences of these species showed that their gene sequences had only 74.9% identity. This low value implies that they are quite different species. After isolation and cultivation of each species, the morphological characteristics were observed. This revealed that the larger species ranging from 20 to 35
was the well known, Cochlodinium polykrikoides and the smaller one ranging from 12 to 25
was Gyrodinium impudicum which had not been reported in Korea. As their 24S rRNA sequences had not been analysed yet, we deposited the sequences in Genbank. At that time of the investigation. the red tide was caused by G. impudicum of which maximum cell counts reached up to 30,000 cells
. In this study we describe the morphological characteristics and the behavioral patterns of each species which can be easily observed with light microscope or stereomicroscope. In addition, their morphology transformed by the fixation with Lugol's solution are also characterized. which can help to discriminate each one in the fixed sample.
Characteristics of Nutrients Distribution in Summer and Winter in the South Sea
Lee, Tong-Sup ;
The Sea, volume 4, issue 4, 1999, Pages 371~382
This paper presents the results of recent nutrients measurement and analysis in relation to other environmental parameters such as temperature, salinity, AOU and pH in the South Sea, Korea. In summer, temperature showed stronger correlation with nutrients than salinity and also did the parameters related to biological activities such as pH and AOU. Implications of above results exemplify that primary producers in the vicinity of salt front actively consumed nutrients so that nutrients-salinity correlation is strongly modified in the salt front. Nutrient in winter showed significant correlation only with temperature. Nutrient distribution seems governed by the location of thermal front between vertically mixed cold water in northern area and warm waters flowing north. Due to weak biological activity in winter pH-nutrients correlation, which was strongest in summer (
>0.6) dropped sharply in winter (
<0.5). Depth integrated nitrate+nitrite, phosphate and silicate values are 321
in summer and 261
in winter, respectively. NIP values in summer exhibit phosphorus deficiency, however, winter situation is reversed for nitrogen. Nitrogen input via precipitation and riverine discharge in wet season seems potentially critical for maintaining the South Sea ecosystem.
Foraminiferal Research in the Korean Yellow Sea
Chang, S.K. ; Lee, H.Y. ;
The Sea, volume 4, issue 4, 1999, Pages 383~389
The foraminiferal researches carried out on the bottom sediments of the Korean Yellow Sea were reviewed. They began from the materials collected in the mid-1960. Most of the study materials were obtained from the gravity or piston corers as well as from the grab samplers. However, relatively long cores were obtained by a drilling ship in the mid-1990. The paleoenvironmental and sea-level histories associated with the foraminiferal changes were the main topics of the foraminiferal researches. Micropaleontological characteristics were also revealed. Sediments were supplied through the input of the rivers and streams from the adjacent mainland China and Korean Peninsula since the Holocene. Although the open sea has influenced off Mokpo now, it had influenced off Kunsan in mid-Holocene which was clearly seen from the occurrence of planktonic foraminifera. However, more advanced methods of study adopting geochemistry such as an absolute age estimate, an isotope analysis and an analysis of elements in combination with other fields of studies related with foraminiferal ecology should be applied to foraminiferal researches to reveal marine geological phenomena, such as climatic fluctuations and related marine environmental changes, in more detail. Additionally, it should be kept in mind that paleontolgical research including foraminifera is essential to the understanding of the recent as well as ancient environmental changes of the earth.
Comparison of Vane-shear Strength Measured by Different Methods in Deep-sea Sediments from KODOS area, NE Equatorial Pacific
Chi, Sang-Bum ; Jung, Hoi-Soo ; Kim, Hyun-Sub ; Moon, Jai-Woon ;
The Sea, volume 4, issue 4, 1999, Pages 390~399
Siliceous and calcareous deep-sea core sediments were collected by a multiple corer from the KODOS (Korea Deep Ocean Study) area, northeast equatorial Pacific, to compare vane shear strengths measured by two different apparatuses and in different places of on-board and on-land laboratories. The apparatuses were 1) a hand-held vane with four blades of
cm, and 2) a motorized shear vane system with four blades of
attached on a rotational viscometer. Depth profiles of shear strengths of core samples determined by the apparatuses do not show any consistent difference. Also, there is no consistent difference between shear strength values measured on-board and on-land laboratories after storing the core samples for three months in a cold room by a motorized shear vane system. However, there are considerable differences between depth profiles of shear strengths measured at four different points (holes) of a core sample. Moreover, significant differences among the profiles of different tube samples from a multiple corer within a sampling station were observed. Heterogeneity in physical properties of each depth and sediment column, possibly due to bioturbation and bottom current flows, is likely responsible for the differences in the geotechnical properties.
Automated Velocity Measurement Technique for Unconsolidated Marine Sediment
Kim, Dae-Choul ; Kim, Gil-Young ; Seo, Young-Kyo ; Ha, Deock-Ho ; Ha, In-Chul ; Yoon, Young-Seok ; Kim, Jeng-Chang ;
The Sea, volume 4, issue 4, 1999, Pages 400~404
The conventional mercury delay method to measure compressional wave velocity of unconsolidated sediment is inconvenient because the signal must be analyzed on the oscilloscope and the mercury column has to be calibrated between measurements. We developed an automated compressional wave velocity measurement technique by connecting an oscilloscope and a PC with a GPIB (General Purpose Interface Bus) card. The GPIB card buses signals from the oscilloscope to the PC where the signal from a sample is analyzed and compared to the input pulse thereby the compressional wave velocity of the sample is computed and recorded automatically. Differences between the mercury delay method and the automated measurement technique are negligible except the slightly greater velocity in the automated measurement technique. We concluded that the new technique can be used to measure the velocity for unconsolidated marine sediment. It also has an advantage to calculate sediment attenuation through the processing of waveform using the spectral ratio technique.