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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Ocean and Polar Research
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Journal DOI :
Korea Institute of Ocean Science & Technology
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Volume & Issues
Volume 34, Issue 4 - Dec 2012
Volume 34, Issue 3 - Sep 2012
Volume 34, Issue 2 - Jun 2012
Volume 34, Issue 1 - Mar 2012
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Phytoplankton Distribution in the Eastern Part of the Yellow Sea by the Formation of Tidal Front and Upwelling during Summer
Lee, Young-Ju ; Choi, Joong-Ki ; Shon, Jae-Kyoung ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 111~123
DOI : 10.4217/OPR.2012.34.2.111
To understand the phytoplankton community in the eastern part of the Yellow Sea (EYS), in the summer, field survey was conducted at 25 stations in June 2009, and water samples were analyzed using a epifluorescence microscopy, flow cytometry and HPLC method. The EYS could be divided into four areas by a cluster analysis, using phytoplankton group abundances: coastal mixing area, Anma-do area, transition water, and the central Yellow Sea. In the coastal mixing area, water column was well mixed vertically, and phytoplankton was dominated by diatoms, chrysophytes, dinoflagellates and nanoflagellates, showing high abundance (
). In Anma-do coastal waters characterized by high dominance of dinoflagellates, high phytoplankton abundance and biomass separated from other coastal mixing area. The southeastern upwelling area was expanded from Jin-do to Heuksan-do, by a tidal mixing and coastal upwelling in the southern area of Manjae-do, and phytoplankton was dominated by benthic diatoms, nanoflagellates and Synechococcus group in this area. Phytoplankton abundance and biomass dominated by pico- and nanophytoplankton were low values in the transition waters and the central Yellow Sea. In the surface of the central Yellow Sea, high dominance of photosynthetic pigments, 19'-hexanoyloxyfucoxanthin and zeaxanthin implies that haptophytes and cyanobacteria could be the dominant group during the summer. These results indicate that the phytoplankton communities in the EYS were significantly affected by the formation of tidal front, thermal stratification, and coastal upwelling showing the differences of physical and chemical characteristics during the summer.
Algicidal Effects of a Newly Developed Thiazolidinedione Derivative, TD49, on Dinoflagellate Akashiwo sanguinea
Baek, Seung-Ho ; Shin, Hyeon-Ho ; Jang, Min-Chul ; Kim, Si-Wouk ; Son, Moon-Ho ; Cho, Hoon ; Kim, Young-Ok ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 125~135
DOI : 10.4217/OPR.2012.34.2.125
To evaluate the algicidal impact of a newly developed algicide thiazolidinedione derivative, TD49, on dinophyceae Akashiwo sanguinea in aquatic ecosystems, tentative culture experiments for the target species were conducted in small (SS), middle (MS), and large scale (LS) culture vessels. When TD49 was introduced at the final concentration of
in SS and MS, as well as
in LS, the abundance of A. sanguinea decreased significantly in all the treatments. On the other hand, total phytoplankton abundance, except A. sanguinea in the TD49 treatments, gradually increased with culture time, which implies that a cell destruction of A. sanguinea by TD49 is a major cause of the population growth by other phytoplankton species. Also, A. sanguinea was easily destroyed, which was likely to be a source of extracellular substances. In particular, a pH decrease was significant in the treatments than in the control, which indicates that the water in the treatments has been acidified, due to an increase in the heterotrophic metabolisms of bacteria and degradation of A. sanguinea cells. Our results indicate that the TD49 substance is the potential agents for the control of A. sanguinea in the enclosed and eutrophic water bodies.
Assessment of Immune Parameters of the Wild Pacific Oyster (Crassostrea gigas) using a Flow Cytometry and Neutral Red Retention Assay
Hong, Hyun-Ki ; Kang, Hyun-Sil ; Kim, Young-Ok ; Choi, Kwang-Sik ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 137~149
DOI : 10.4217/OPR.2012.34.2.137
Hemocyte parameters of the wild Pacific oyster Crassostrea gigas inhabiting intertidal zones in small bays (Gwangyang and Jinhae Bay) on the southern coast of Korea were evaluated using flow cytometry and neutral red retention (NRR) assay. Morphological features, cell count, mortality, DNA damage, phagocytosis, and lysosomal membrane stability of hemocytes were analyzed. Three types of hemocytes were identified in the oyster hemolymph: granulocytes, hyalinocytes, and blast-like cells. Immune related functions of hemocyte including phagocytosis and lysosomal membrane stability were significantly different among the study areas (P<0.05), while cell count, mortality, and DNA damage of hemocytes were not significantly different. In Gwangyang Bay, phagocytosis of granulocytes and lysosomal membrane stability of oyster hemocytes inhabiting inside bay were significantly lower than those of oyster hemocytes in outside bay (P<0.05), indicating that oysters in inside bay of Gwangyang were relatively suppressed the immunological function in hemocytes. Contrary to Gwangyang Bay, immune parameters of oyster hemocytes in Jinhae Bay not showed the difference between sampling sites. In conclusion, flow cytometry and NRR assay using oyster hemocyte has a powerful tool to investigate the cell level in a short time due to no-preprocessing of material.
Cytochemical Measurement of Lysosomal Responses in the Digestive Cells of Wild Pacific Oyster, Crassostrea gigas on the South Coast of Korea
Jeung, Hee-Do ; Lee, Jee-Yeon ; Hong, Hyun-Ki ; Kang, Hyun-Sil ; Kim, Young-Ok ; Choi, Kwang-Sik ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 151~163
DOI : 10.4217/OPR.2012.34.2.151
Digestive cells of the bivalves have a highly developed lysosomal system and the system is known to be sensitive to changes in environmental qualities. In this study, we measured lysosomal responses of the digestive cells in wild oyster, Crassostrea gigas using frozen section. Oysters were collected in June 2010 from intertidal areas in the inner and outer bay of Gwangyang off the south coast of Korea. From the tissue sections, we measured the digestive cell lysosomal membrane stability (LMS), level of neutral lipids (NL), lipofuscin (LF) and the digestive gland atrophy (DGA). The DGA and condition index of oysters from the inner bay were significantly lower (P<0.05). The statistical test indicated that LMS levels of oysters in the inner bay and the outer bay were not significantly different since a shorter activity was displayed by oysters from the inner bay than that of oysters in outer bay. The LF deposition level of the oysters in the inner bay displayed significantly higher levels than the outer bay (P<0.05). In contrast, the NL accumulation measured from oysters in outer bay was significantly higher than the level observed in the inner bay (P<0.05). Different levels of DGA and LF that were observed in the inner and outer bays were thought to be associated to different level of environmental contamination and these two assays are considered to be good biomarkers.
Effects of Starvation on the Morphometric Characteristics and Histological Changes in Chum Salmon (Oncorhynchus keta) Fry
Seong, Ki-Baik ; Park, In-Seok ; Goo, In-Bon ; Kim, Dong-Soo ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 165~173
DOI : 10.4217/OPR.2012.34.2.165
A 26 day experiment was conducted to determine the effects of feeding and starvation on the survival, morphology, and histology in chum salmon (Oncorhynchus keta) fry. We included three experimental groups: starved, fed, and initial. The survival and growth rates were lower in the starved group than in the fed group (P < 0.05). In the starved group, survival began to decline after 16 days, and all fish had died after 26 days. We determined the effects of starvation on the morphometric parameters using the truss and classical dimensions. The dimensions in the head region were larger in the starved group than in the initial and fed groups. In contrast, the truss dimensions of the fed group were larger than those of the initial and starved groups. Starvation reduced the heights of the hepatocyte nuclei and of the intestinal epithelium (P < 0.05). The starved group also showed atrophy of the digestive structures and shrinkage of the foregut and midgut. Starvation led to the degeneration and atrophy of the exocrine pancreas, in which the lumen was markedly diminished and the folds of mucosa were less apparent. The hepatocyte morphology in the starved group was abnormal compared with that of the initial and fed groups, with highly compact, irregularly shrunken nuclei. Melanomacrophages were randomly distributed in the kidneys of the starved group, and their abundance increased rapidly during the experiment. In contrast, neither the initial nor fed group had any melanomacrophages. These results suggest that the nutritional parameters used in this study are useful indices of nutritional status in chum salmon.
Non-market Benefits of Building the Large Oceanographic Research Ship
Yoo, Seung-Hoon ; Kwon, Suk-Jae ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 175~183
DOI : 10.4217/OPR.2012.34.2.175
A project to build a large oceanographic research ship was proposed to improve the level of ocean research. This paper attempts to measure the non-market benefits of the project. To this end, the dichotomous choice contingent valuation method is used. In particular, the recently proposed one and one-half bounded model is applied. The model can reduce the potential for response bias compared to the double bounded model, while maintaining much of its efficiency. Moreover, in order to deal with zero WTP observations, a spike model is adjusted for our data. A survey of 500 randomly selected households was implemented in the Metropolitan area. The respondents were asked in person-to-person interviews about how they would be willing to pay for implementing the project. Overall, respondents accepted the contingent market, and were willing to contribute a significant amount (3,244 won), on average, per household per year. The aggregate value of the project nationwide would amount to approximately 40.1 billion won per year.
A Study on Forecast of Oyster Production using Time Series Models
Nam, Jong-Oh ; Noh, Seung-Guk ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 185~195
DOI : 10.4217/OPR.2012.34.2.185
This paper focused on forecasting a short-term production of oysters, which have been farmed in Korea, with distinct periodicity of production by year, and different production level by month. To forecast a short-term oyster production, this paper uses monthly data (260 observations) from January 1990 to August 2011, and also adopts several econometrics methods, such as Multiple Regression Analysis Model (MRAM), Seasonal Autoregressive Integrated Moving Average (SARIMA) Model, and Vector Error Correction Model (VECM). As a result, first, the amount of short-term oyster production forecasted by the multiple regression analysis model was 1,337 ton with prediction error of 246 ton. Secondly, the amount of oyster production of the SARIMA I and II models was forecasted as 12,423 ton and 12,442 ton with prediction error of 11,404 ton and 11,423 ton, respectively. Thirdly, the amount of oyster production based on the VECM was estimated as 10,425 ton with prediction errors of 9,406 ton. In conclusion, based on Theil inequality coefficient criterion, short-term prediction of oyster by the VECM exhibited a better fit than ones by the SARIMA I and II models and Multiple Regression Analysis Model.
Assessment of the Impact of Climate Change on Marine Ecosystem in the South Sea of Korea
Ju, Se-Jong ; Kim, Se-Joo ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 197~199
DOI : 10.4217/OPR.2012.34.2.197
According to the IPCC climate change scenario (A1B scenario), the surface seawater temperature of the South Sea of Korea by 2100 may be
higher than at present, and seawater pH may decrease from 8.1 to 7.8, due to the increase in atmospheric
, which is predicted to increase in concentration from 380 to 750 ppm. These changes may not only intensify the strength of typhoons/storm surges but also affect the function and structure the marine ecosystem. In order to assess the impact of climate change on the marine ecosystem in Korean waters, the project named the 'Assessment of the impact of climate change on marine ecosystem in the South Sea of Korea' has been supported by the Ministry of Land, Transport and Maritime Affairs, from 2008. The goal of this project is to enhance our ability to adapt and prepare for the future environmental changes through the reliable predictions based on the knowledge obtained from projects like this. In this respect, this project is being conducted to investigate the effects of climate/marine environment changes (ocean warming and acidification), and to predict future changes of the structure and function of the ecosystem in the South Sea of Korea. This special issue contains 6 research articles, which are the highlights of the studies carried out through this project.
Climatological Variability of Satellite-derived Sea Surface Temperature and Chlorophyll in the South Sea of Korea and East China Sea
Son, Young-Baek ; Ryu, Joo-Hyung ; Noh, Jae-Hoon ; Ju, Se-Jong ; Kim, Sang-Hyun ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 201~218
DOI : 10.4217/OPR.2012.34.2.201
The purpose of this study is to investigate climatological variations from the sea surface temperature (SST), chlorophyll-a concentration (Chl-a), and phytoplankton size class (PSC), using NOAA AVHRR, SeaWiFS, and MODIS data in the South Sea of Korea (SSK) and East China Sea (ECS). 26-year monthly SST and 13-year monthly Chl-a and PSC data, separated by whole and nine-different areas, were used to understand seasonal and inter-annual variations. SST and Chl-a clearly showed seasonal variations: higher SST and Chl-a were observed during the summer and spring, and lower values occurred during the winter and summer. The annual and monthly SST over 26 years increased by
. The annual and monthly Chl-a concentration over 13 years decreased by
. To determine more detailed spatial and temporal variations, we used the combined data with monthly SST, Chl-a, and PSC. Between 1998 and 2010, the inter-annual trend of Chl-a decreased, with decreasing micro- and nano-size plankton, and increasing pico-size plankton. In regional analysis, the west region of the study area was spatially and temporally correlated with the area dominated by decreasing micro-size plankton; while the east region was less sensitive to coastal and land effects, and was dominated by increasing pico-size plankton. This phenomenon is better related to one or more forcing factors: the increased stratification of ocean driven by changes occurring in spatial variations of the SST caused limited contributions of nutrients and changed marine ecosystems in the study area.
Using Tintinnid Distribution for Monitoring Water Mass Changes in the Northern East China Sea
Kim, Young-Ok ; Noh, Jae-Hoon ; Lee, Tae-Hee ; Jang, Pung-Guk ; Ju, Se-Jong ; Choi, Dong-Lim ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 219~228
DOI : 10.4217/OPR.2012.34.2.219
Tintinnid species distribution has been monitored in the northern East China Sea (ECS) in the summer of 2006 through 2011. This is used to understand the water mass movements in the northern ECS. The warm oceanic tintinnid species had largely spread in 2007 in the area, indicating that there was greater warm water extension into the northern ECS. However the extension of neritic water within the Changjiang diluted water mass has strengthened in 2008 and 2010 because the neritic species distribution had relatively grown in both years. These annual results based on the biological indicators of tintinnid species are well matched with the salinity change in the area. The warm oceanic species, Dadayiella ganymedes had frequently occurred over the study years and had shown a significant relationship with the salinity change. This is valuable as a key stone species for monitoring the intrusion of the Kuroshio within the northern ECS. Information from tintinnid biological indicators can support physical oceanography data to confirm ambiguous water mass properties.
Assessment of Changes in Temperature and Primary Production over the East China Sea and South Sea during the 21st Century using an Earth System Model
Park, Young-Gyu ; Choi, Sang-Hwa ; Kim, Seon-Dong ; Kim, Cheol-Ho ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 229~237
DOI : 10.4217/OPR.2012.34.2.229
Using results from an Earth System model, we investigated change in primary production in the East China Sea, under a global warming scenario. As global warming progresses, the vertical stratification of water becomes stronger, and nutrient supply from the lower part to the upper part is reduced. Consequently, so is the primary production. In addition to the warming trend, there is strong decadal to interdecadal scale variability, and it takes a few decades before the warming trend surpasses natural variability. Thus, it would be very hard to investigate the global warming trend using data of several years' length.
Predicting Impacts of Climate Change on Sinjido Marine Food Web
Kang, Yun-Ho ; Ju, Se-Jong ; Park, Young-Gyu ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 239~251
DOI : 10.4217/OPR.2012.34.2.239
The food web dynamics in a coastal ecosystem of Korea were predicted with Ecosim, a trophic flow model, under various scenarios of primary productivity due to ocean warming and ocean acidification. Changes in primary productivity were obtained from an earth system model 2.1 under A1B scenario of IPCC
emission and replaced for forcing functions on the phytoplankton group during the period between 2020 and 2100. Impacts of ocean acidification on species were represented in the model for gastropoda, bivalvia, echinodermata, crustacean and cephalopoda groups with effect sizes of conservative, medium and large. The model results show that the total biomass of invertebrate and fish groups decreases 5%, 11~28% and 14~27%, respectively, depending on primary productivity, ocean acidification and combined effects. In particular, the blenny group shows zero biomass at 2080. The zooplankton group shows a sudden increase at the same time, and finally reaches twice the baseline at 2100. On the other hand, the ecosystem attributes of the mean trophic level of the ecosystem, Shannon's H and Kempton's Q indexes show a similar reduction pattern to biomass change, indicating that total biomass, biodiversity and evenness shrink dynamically by impacts of climate change. It is expected from the model results that, after obtaining more information on climate change impacts on the species level, this study will be helpful for further investigation of the food web dynamics in the open seas around Korea.
Prediction of the Spawning Ground of Todarodes pacificus under IPCC Climate A1B Scenario
Kim, Jung-Jin ; Min, Hong-Sik ; Kim, Cheol-Ho ; Yoon, Jin-Hee ; Kim, Su-Am ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 253~264
DOI : 10.4217/OPR.2012.34.2.253
In the northwestern Pacific, spawning of the common squid, Todarodes pacificus, occurs at continental shelf and slope areas of 100-500 m, and the optimum temperature for the spawning and survival of paralarvae is assumed to be
. To predict the spawning ground of Todarodes pacificus under future climate conditions, we simulated the present and future ocean circulations, using an East Asia regional ocean model (Modular Ocean Model, MOM version3), projected by two different global climate models (MPI_echam5, MIROC_hires), under an IPCC SRES A1B emission scenario. Mean climate states for 1990-1999 and 2030-2039 from 20th and 21th Century Climate Change model simulation (from the IPCC 4th Assessment Report) were used as surface conditions for simulations, and we examined changes in spawning ground between the 1990s and 2030s. The results revealed that the distribution of spawning ground in the 2030s in both climate models shifted northward in the East China Sea and East Sea, for both autumn and winter populations, compared to that of the 1990s. Also, the spawning area (with
grid) in the 2030s of the autumn and winter populations will decline by 11.6% (MPI_echam5) to 30.8% (MIROC_hires) and 3.0% (MPI_echam5) to 18.2% (MIROC_hires), respectively, from those of the 1990s.
Development of Algorithms for Extracting Thermocline Parameters in the South Sea of Korea
Yoon, Dong-Young ; Choi, Hyun-Woo ;
Ocean and Polar Research, volume 34, issue 2, 2012, Pages 265~273
DOI : 10.4217/OPR.2012.34.2.265
A new algorithm was developed, not only to detect the existence of a thermocline, but also to extract the thermocline parameters (such as thermocline thickness, mixed layer thickness, maximum temperature gradient, and temperature difference of thermocline), using the vertical profile of water temperature. According to Kappa analysis, in order to find adequate threshold values of vertical water temperature gradients
), agreement and reliability were 87% and 0.74 respectively, in the conditions of maximum
and surface and bottom layers
. Also, three different kinds of methods, viz. 1. Gradient method, 2. Hyperbolic tangent method, and 3. Differential hyperbolic tangent method, were tested to extract the key parameters of a thermocline. Comparing the results of three different methods, the differential hyperbolic tangent method was the most appropriate to extract the start and end point of a thermocline curve.