• Ocean and Polar Research
• /
• v.38 no.2
• /
• pp.139-148
• /
• 2016

The activity concentrations of $^{210}Po$ and $^{210}Pb$ within phytoplankton-zooplankton-anchovy-mackerel in the coastal water of the Jeju Island were determined to understand their distribution and bio-accumulation along the trophic level. In the surface water, the total activity concentrations of $^{210}Po$ and $^{210}Pb$ were $0.83{\pm}0.004mBq\;kg^{-1}$ and $1.27{\pm}0.03mBq\;kg^{-1}$. And the dissolved activity concentration of $^{210}Po$ and $^{210}Pb$ were $0.75{\pm}0.06mBq\;kg^{-1}$ and $1.22{\pm}0.09mBq\;kg^{-1}$ respectively. In the phytoplankton, the concentration factor (CF) of $^{210}Po$ and $^{210}Pb$ were $1.5{\times}10^5$ and $2.6{\times}10^4$ shows $^{210}Po$ is 5 times higher compared to $^{210}Pb$. The similar CF factor in the zooplankton of $^{210}Po$ was derived as $1.4{\times}10^5$. The CF of $^{210}Po$ in anchovy was increased twice compared to that in plankton. This is the evidence that there is $^{210}Po$ bio-magnification in the trophic level of plankton-anchovy. However the $^{210}Po$ activity concentration in the muscle tissue of mackerel was one-hundred times lower than that in anchovy. This reflects that in the trophic level of anchovy-mackerel, the bio-accumulation of $^{210}Po$ is decreased. The activity concentrations of $^{210}Po$ in the internal organs of anchovy and mackerel were 8 to 38 times higher than those in muscle tissues. In phytoplankton-zooplankton-anchovy, the CF of $^{210}Pb$ was decreased five times along the trophic level in order. In anchovy-mackerel it was decreased by 30-70%.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.1
• /
• pp.15-26
• /
• 2008

The NEMURO model is aimed to efficiently understand the interaction among factors of lower trophic level of a marine ecosystem, using data on solar radiation and sea water temperature. In this study, we analyzed the seasonal pattern of nutrients and planktons, and estimated productivity and biomass of planktons from 2002 to 2005. Nutrients($NO_3$, $NH_4$, and $Si(OH)_4$) which were used by phytoplankton showed a high concentration before the bloom of phytoplankton. Nutrients (DON, PON, and Opal) which were a byproduct of phytoplankton showed a high concentration in the same period as the bloom of phytoplankton. Both phytoplankton and zooplankton had two peaks in March and August. Estimated phytoplankton biomass from the NEMURO model showed a similar pattern with observed chlorophyll a concentrations. Biomasses of phytoplankton were bigger than those of zooplankton. Annual mean biomasses of small and large phytoplankton were estimated at 30.961 and $14.070\;{\mu}g\;l^{-1}$ respectively. Annual mean biomass of predatory zooplankton was greater than those of small and large zooplankton.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.5
• /
• pp.493-505
• /
• 2020

Food web structures in the lower trophic levels of the seas around the Korean peninsula were investigated in August 2019 using stable isotopes. There were variable ratios of the carbon (-26.18 ~ -20.61 ‰) and nitrogen stable (5.36 ~ 15.20 ‰) isotopes in the particulate organic matter (POM). Most of the organisms ingested micro-POM as a major food source, but this varied spatially. The chaetognaths (3.40 ± 0.61) occupied the highest trophic level. The isotope mixing model showed that the proportions (13 ~ 51 %) of some organisms (i.e., copepods and euphausiids) reflected the relative contributions as major food sources for chaetognaths at each site.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.3
• /
• pp.193-198
• /
• 2012

Long term changes in winter time(JFM) sea surface temperature(SST) and marine ecosystem of different Korean waters during last five to six decades were illustrated. Fishing intensity with climate-ocean variability(e.g. SST) have been increasing since 1970s in all of the Korean marine waters. Winter SST around Korean waters went to colder regime in early 1980s and after the late 1980s increased gradually. After 1988/89 CRS all of the waterbody started warmer regime and well coincided with the CRS phenomena. Large predatory, small pelagic and crustacean and mollusks abundance were well coincided by the warmer SST regime after 1988/89 CRS and changed the fishery from demersal fishery to pelagic fishery. Ecosystem parameter of Mean Trophic Level(MTL) showed continuous decreasing trend since mid of 1970s which was mostly affected by the increasing of lower trophic level species. Fishing in balance(FIB) index showed increasing pattern since early 1970s to the late of 1970s and from early 1980s it was almost stable until now. Finally wasp-waist population of anchovy and Japanese sardine have a greater impact to the whole MTL since early 1970s.

• Journal of Environmental Science International
• /
• v.31 no.6
• /
• pp.491-501
• /
• 2022

This study evaluated the contamination levels of inland pollution sources flowing into Taeanhaean National Park. The nutritional status of influents was assessed by analyzing water quality and trophic status index (TRIX) at 52 stations, and the contamination levels of sediments were evaluated by analyzing eutrophication cleanup index (CIET) and heavy metals at 36 stations. The results of the TRIX analysis showed that 26 of the 52 stations had influents with a TRIX value of 6-10 (poor water quality/very high trophic level), indicating atrocious water quality and high eutrophication levels. The results of the CIET analysis showed that 4 out of the 36 stations were highly contaminated with organic matter. Analysis of heavy metals showed that the copper (Cu) and zinc (Zn) levels exceeded the threshold effects level (TEL) and probable effects levels (PEL) at several stations. In addition, the arsenic (As) level exceeded the threshold effects level at one station, and the levels of the other heavy metals (Cd, Cr⁶⁺, Ni, Pb, and Hg) were lower. Most inland pollution sources have been identified as small-scale, but long-term and continuous exposure can negatively affect the marine ecosystem; therefore, it necessary to prepare inland pollution source management standards and measures suitable for the characteristics of the coastal area.

• The Korean Journal of Pain
• /
• v.18 no.2
• /
• pp.240-245
• /
• 2005

Herein is described the successful treatment of complex regional pain syndrome type II with the combination treatment of spinal cord stimulation and radiofrequency thermocoagulation of the lumbar sympathetic ganglion. A 62 years old male patient, suffering from CRPS type II in his left lower extremity, visited our pain clinic. Medication and nerve blockade produced only slight improvement in his symptoms and signs. Therefore, a linear type spinal cord simulator was inserted into the thoracic epidural space, using a non-surgical percutaneous approach, with the cephalad lead located at the T11 level. Two months later, the repositioning of the electrode to the T12 level for more effective pain control, with radiofrequency thermocoagulation of lumbar sympathetic ganglion also performed at the left L2 and 3 levels for the control of trophic change. These resulted in significant pain relief and decreased trophic change, with no complications, after which the patient was able to resume a normal life.

• Journal of the korean society of oceanography
• /
• v.39 no.1
• /
• pp.14-19
• /
• 2004

Difference of Dissolved Inorganic Phosphorus (DIP), Dissolved Inorganic Nitrogen (DIN) and Dissolved Silicate (DSi) budgets in the Bohai Sea between 1982 and 1992 related the decrease of the Yellow River discharge is discussed on the basis of observed data. The estuarine circulation in the Bohai Sea had been weakened from 1982 to 1992 due to the decrease of the Yellow River discharge and the average residence time of fresh water had become longer. DIN concentration increased but DIP and DSi concentrations decreased from 1982 to 1992 in the Bohai Sea. Primary production was regulated mainly by water temperature and DIN concentration in 1982 but it was regulated mainly by DIP concentration in 1992. Primary production was larger than decomposition plus bottom release and nitrogen fixation was larger than denitrification in 1982. However, decomposition plus bottom release was larger than primary production and denitrification was larger than nitrogen fixation in 1992 in the Bohai Sea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.3
• /
• pp.230-236
• /
• 1987

The correlation between tintinnid and dinoflagellate by means of seasonal variation of standing crops was investigated at two selected stations in Masan Bay, well-known as a red tide zone in southern coastal waters of Korea, during the period from January 1981 to December 1982. The most dominant dinoflagellates mainly belonged to $20-60\;{\mu}m$ of size class, and Gymnodinium and Prorocentrum were predominant from spring to summer season. Of tintinnid, Favella spp. were most dominant and associated with dinoflagellate blooms at the same season. Especially, Favella spp. were most positively correlated with $40-60\;{\mu}m$ size class of dinoflagellate, and also represented higher multiple corrleation with outer station (St.2), comprising relatively large species of Gymonodinium and Protogonyaulax, than with inner station (St. 1), dominated by Prorocentrum blooms. Thus, the interspecific food selection by size and morphology between tintinnid including Favella and dinoflagellate is recognized and it is considered to be an important factor influenecing on the prey-predator relationship in lower trophic level in the surveyed area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.5 no.1
• /
• pp.10-15
• /
• 2000

Goals, research direction, and operational structure of the Global Ocean Ecosystem Dynamics (GLOBEC), which is co-sponsored by the Scientific Committee on Oceanic Research (SCOR) and the Intergovemmental Oceanographic Commission (IOC), are described. Following the Joint Global Ocean Flux Study (JGOFS) activities on the lower trophic level in ecosystem during 1980s-90s, scientists have considered the responses of the mid and higher trophic levels to the environmental or climate change. The scientific steering committee of the GLOBEC published the implementation plan in 1999, and the IGBP will support the GLOBEC as one of its core projects for 10 years. The GLOBEC programme has four major components: the research foci, framework activities, regional programmes, and integrating activity. The core of GLOBEC research is the four research foci: retrospective analyses, process studies, predictive and modelling capabilities, and feedbacks. Currently, four regional programmes have been undergoing in the world ocean: Southern Ocean GLOBEC (SO-GLOBEC), Small Pelagic Fishes and Climate Changes (SPACC), Cod and Climate Change (CCC), and Climate Change and Carrying Capacity (CCCC). Also, national GLOBEC programmes were already established in 9 nations.

• ALGAE
• /
• v.23 no.4
• /
• pp.257-268
• /
• 2008

Species composition, standing crop and dominant species of phytoplankton were investigated at 6 sites of Galgok stream and Incheon river which run into Gomso Bay, Jeollanam-do in April, August and November 2007. Total of 210 taxa were found which were classified as 6 classes, 12 orders, 25 families, 66 genera, 177 species, 27 varieties, 5 forms and 1 unidentified species. These river and stream had lower concentration of T-N and T-P compared to that of others; however, the site 2 of Galgok stream in summer was hypertrophic in T-P and also near hypertrophic in TN, and the site 1 in Incheon river during fall appeared to be hypertrophic in T-N, and the site 3 in summer showed near hypertrophic level in T-P. Determining the trophic status of the water quality based on chlorophyll a (chl-a), the site 3 of Galgok stream in spring and the site 3 of Incheon river in fall were oligotrophic; moreover, 6 sites including the site 2 and 3 of Galgok stream in summer were mesotrophic, and 9 sites including all sites of Galgok stream in fall turned out to be eutrophic. Particularly, the site 1 of Galgok stream in summer was hypertrophic, having 58.19 mg chl-a m$^{-3}$. There was a conspicuous difference between two values of standing crops based on chl-a and cell counting. This discrepancy may have occurred because of abundant cyanophytes and exclusion of picoplankton cells in cell counting. In the study, 5 cyanophytes, Synechocystis aquatilis, Microcystis aeruginosa, M. flos-aquae, Oscillatoria angustissima, O. limnetica and 2 diatoms, Thalassiosira bramaputrae and Navicula viridula var. rostellata were abundant. Based on the T-N, T-P values, standing crops and cell counting in Galgok stream and Incheon river were between mesotrophic and eutrophic conditions.