• Journal of Wetlands Research
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• v.6 no.1
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• pp.133-147
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• 2004

Environmental quality(water and sediment) was analyzed in the tidal flat of Saemangum of Jeonbuk Province, the west coast of Korea, using the 101 sediment samples and 69 water samples collected in September 4~13, 2001. Major water quality parameters with the means of 69 surface water samples are as follows; $25.51{\pm}0.68^{\circ}C$ for water temperature, $29.88{\pm}5.01$ for salinity, $1.40{\pm}0.78mg/L$ for COD, $0.352{\pm}0.417mg/L$ for DIN, and $0.027{\pm}0.023mg/L$ for phosphate, respectively. Higher values were found at the subestuary of Dongjin and Mangyung River, and lower values at the Saemangum embayment and Gomso Bay. There was a significant negative correlation between salinity and the other water quality parameters(p<0.0001) such as COD, nutrients, SS and N/P. This correlation suggested that the major pollution sources be from terrestrial inputs through tributaries in this area. Principal component analysis clearly revealed a spatial variation of water quality; stations with higher values of nutrients and COD located subestuary of tributaries. 14 sediment quality parameters including 8 trace metals were measured using the 101 surface sediment samples. Average values for the parameters are as follows; Al $2.28{\pm}0.92%$, Cd $0.61{\pm}0.27ppm$, Cu $8.95{\pm}4.06ppm$, Fe $1.19{\pm}0.37%$, Mn $182.31{\pm}77.45ppm$, Ni $10.83{\pm}4.97ppm$, Pb $15.20{\pm}4.35ppm$, Zn $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, IL $1.29{\pm}1.08%$, water content $24.11{\pm}4.49%$, TN $0.02{\pm}0.02%$, TC $0.22{\pm}0.30%$. Spatial variations of sediment quality were not clear as water quality. Some higher values were found at the subestuary of Gum River and lower values at the other area. There was a significant positive correlation between the heavy metal concentrations and organic materials within the sediment(p<0.05). Enrichment factors showed the ranges of 1~2 for most of the metals in the sediment except zinc(1~6), indicating no serious exogenous input of heavy metals in the study area. Also, the heavy metal concentrations in the sediment were within the ranges found at the natural marine environments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.889-894
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• 1998

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of marine pollutions by changes in oxygen radicals and their scavenger enzymes of the flounder (Paralichthys olivaceus) in the South Sea of Korea. Protein contents in brain and muscle of cultured flounder in the South Sea were remarkably lower ($19\~42\%$ and $25\~41\%$, respectively) than those of wild flounder in Pohang of the East Sea as a control group. Lipid Peroxide (LPO) levels in serum of cultured in the South Sea were considerably higher ($5\~33\%$) Elan those of wild flounder in Pohang. Hydroxyl radical formations in serum of cultured flounders in the South Sea were lower ($4\~25\%$) than those of wild flounders in Pohang. Superoxide dismutase (SOD) activities in serum of cultured flounders in South Sea were also significantly lower ($7\~31\%$) than those of wild flounders in Pohang. It is believed that significant decrease of protein contents in brain and muscle, and remarkable increases of LPO in serum of cultured flounders may be used as a biochemical pollutant markers for diagnosis of marine pollutions. These results suggest that near-coastal water as well as neritic water of the South Sea might be affected by pollutant input as well as the Yellow Sea of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.527-536
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• 1996

The patterns of diel horizontal migration (DHM) of 7 copepod species are compared as part of a general investigation of the zooplankton adaptations to the surf zone habitats. In a sandy shore surf zone of Yongil Bay, 3 sites such as the bottom and surface of 1 m water depth and water's edge are sampled with a sledge net(n=108). The surf zone copepod assemblage is dominated by 7 species; Acartia hudsonica, Fseudodiaptomus marinus, Paracalanus indicus, Calanus sinicus, Oithona similis, Sinocalanus tenellus and Labidocera bipinnata. Threefold variations in copepod abundance are observed within a diel cycle. Abundances of 7 dominant species and total copepods captured in the surface exhibit significant diel differences, but those taken in the bottom are not significantly affected by diel period. It is shown that about $90\%$ of the surf zone copepods performed DHM. The nocturnal high densities of copepods occurred for a neap tide when the offshore winds prevailed, suggesting the animals' ability for horizontal orientation and an active locomotion without invoking passive transportation by currents. Photoreactive behavior of copepods triggered by relative changes in light intensity may be a primary factor inducing DHM by aggregating in the surf zone during the night and spreading out at day; then copepods may reduce encounters with visual predators. In A. hudsonica, ontogenetic variations in timings of DHM are evident. Such variations are likely to minimize intraspecific competition for diets. Data on shoreward migration of copepods indicate that A. hudsonica, P. indicus, O. similis and S. tenellus can maintain swimming velocities of about $20m\;h^{-1}$ for durations of more than an hour. Our observations of strong diel difference in abundances point out the need for both day and night samplings in surf zone habitats, if the importance of these habitats to planktonic copepods are to be fully understood.

• Korean Journal of Environmental Biology
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• v.32 no.2
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• pp.138-152
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• 2014

The objective of the study survey was to determine the effect of marine sand extraction on community composition and rate of recolonization of the meiobenthos following cessation of mining activities. Because of meiobenthic distribution in nature, high abundance, intimate association with sediments, fast reproduction, benthic larva period, sensitivity to pollution and rapid life histories, meiobenthos are widely regarded as ideal organisms to study the potential ecological indicator of natural and anthropogenic stresses. The community structure of meiobenthos was studied at seven stations within sandy tidal and sub tidal zones in Jangbongdo in the Yellow Sea, Korea from Aug. 2006 to Dec. 2007. Meiobenthic samples were collected by three core samples, with a 3.6 cm in diameter, from each sediment sample taken with a Smith-McIntyre Grab. It was found that sand mining often causes complete removal of the sediment and the damage to the habitats of meiobenthos. This study in the effect showed that sand mining resulted in a reduction in total abundance and biomass of meiobenthos in mining area. The finding of this study further showed that initial restoration of abundance and biomass within one year of the cessation of sand mining.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.3
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• pp.125-151
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• 2018

We grouped the names attributed to the seas surrounding the Korean Peninsula in maps published in two major Korean ocean and fisheries science journals over the period from 1998 to 2017: the Journal of the Korean Society of Oceanography (The Sea) and the Korean Journal of Fisheries and Aquatic Science (KFAS). The names attributed to these seas in maps of journal paper broadly were classified into three groupings: (1) East Sea and Yellow Sea; (2) East Sea, Yellow Sea, and South Sea; or (3) East Sea, West Sea and South Sea. The name 'East Sea' was dominantly used for the waters between Korea and Japan. In contrast, the water between Korea and China has been mostly labelled as 'Yellow Sea' but sometimes labelled as 'West Sea'. The waters between the south coast of Korea and Kyushu, Japan were labelled as either 'Korea Strait' or 'South Sea'. This analysis on sea names in the maps of 'The Sea' and 'KFAS' reveals that domestic researchers frequently mix geographical and international names when referring to the waters surrounding the Korean Peninsula. These inconsistencies provide the motivation for the development of a basic unifying guideline for naming the seas surrounding the Korean Peninsula. With respect to this, we recommend the use of separate names for the marginal seas between continental landmasses and/or islands versus for the coastal waters surrounding Korea. For the marginal seas, the internationally recognized names are recommended to be used: East Sea; Yellow Sea; Korea Strait; and East China Sea. While for coastal seas, including Korea's territorial sea, the following geographical nomenclature is suggested to differentiate them from the marginal sea names: Coastal Sea off the East Coast of Korea (or the East Korea Coastal Zone), Coastal Sea off the South Coast of Korea (or the South Coastal Zone of Korea), and Coastal Sea off the West Coast of Korea (or the West Korea Coastal Zone). Further, for small or specific study areas, the local region names, district names, the sea names and the undersea feature names can be used on the maps.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.109-118
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• 2000

The dynamics of inorganic nutrients and phytoplankton population were examined at eight stations of Shihwa Reservoir, which situated near the cities newly constructed and the industrial complex of West-sea in Korea, from January to December 1999. Among environmental factors, average concentration of $NH_4$, SRP and SRSi were $522.7\;{\mu}g\;N/l$, $9.8\;{\mu}g\;N/l$ and $0.26\;{\mu}g\;Si/l$, respectively. Water quality was extremely deteriorated by a great amount of pollutants load into inner reservoir after the event of rainfall. Nutrients concentration was suddenly decreased toward the lower part. While $NO_3$ concentration did not much varied among stations, but it was relatively high in winter season. Chlorophyll-a concentration was high at the upper part of the reservoir, with average of $37.2\;{\mu}/l$, and closely related to the fluctuation of $NH_4$, SRP and SRSi concentrations. The phytoplankton development in the water column was dominated by diatom (autumn), prasinoid (winter) and dinoflagellate (summer). Dominant phytoplankton were composed to Skeletonema costatum of diatom, Prorocentrum minimum of dinoflagellate, Chroomonas spp. of cryptomonad, Eutreptiella gymnastica of euglenoid and Pyramimonas spp. of prasinoid. The large bloom of phytoplankton at the upper zone of the Shihwa Reservoir after inflow of a seawater were consistently observed. In consequence, water quality management of the inlet stream was assessed to be very important and urgent.

• Korean journal of food and cookery science
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• v.28 no.2
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• pp.207-214
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• 2012

In this study, cabbage ($Brassica$ $oleracea$ var. $capitata$) Kimchi was made packed into four kinds of packaging materials, PET vessel, PP tray, OPP/AL/PE film and Nylon/PE/LLDP film, and the effects of these packaging materials on Kimchi quality characteristics, such as lactic acid bacteria counts, salinity, sugar contents, pH, total acidity, electron donating ability were examine as well as their effects on the sensory qualities after storage at a temperature of $4^{\circ}C$. The pH change ranged from pH 6.24 to 6.43 shortly after manufacture, and did not significantly change until 7 days of storage. However, it began to decrease rapidly after 14 days. On the 35th day of storage, the acidity was 0.79% in the PET vessel and 0.83% in OPP/AL/PE. Therefore, the PET vessel and OPP/AL/PE were considered appropriate packaging materials for Kimchi storage. The salinity did not change significantly during the storage period, and the sugar content generally increased in the four kinds of packaging materials, but decreasing after the 7th day of storage. After 14 days of storage, the Kimchi stored in the OPP/AL/PE film showed the highest lactic acid bacteria counts. Although the electron donating ability was the highest after proper time for fermentation, it decreased in all the packaging materials after the proper time for fermentation. However, the OPP/AL/PE film had an antioxidant potential of up to 93.18%. In the sensory evaluation, fermented Kimchi was found to be superior unfermented Kimchi. In addition, the Kimchi stored in the OPP/AL/PE film for 14 days showed the high score of 6.70 and 6.60 in overall preference. Therefore, the results of this study provide basic knowledge on the fermentation level and packaging material's condition for commercialization of small packed cabbage Kimchi. Henceforth, industrialization must include a variety of studies under these conditions to increase the merchantability.

• Journal of fish pathology
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• v.2 no.2
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• pp.53-70
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• 1989

An ovarian parasite, Marteilioides chungmuensis of the Pacific oyster, Crassostrea gigas has been observed on several occasions in the Pacific sector of production of this oyster species(Matsuzato et al., 1977 ; Chun, 1979). This study was carried out on the specimens collected at Hwado, Och'$\check{o}$n, and Sinchang respectively located the southern, western, and eastern coasts of Korean Peninsula from 1986 through 1988 to investigate M. chungmuensis to the Pacific oyster. Uitrastructural studies were also carried out on infected oysters, to allow detailed examination of the structure and consepuently the systematic position of this parasite. Infection rates of M. chungmuensis at Hwado and Och'$\check{o}$n oyster farms were 5.3% and 4.2% each in 1986, 6.7% and 2.8% each in 1987, but they were not found at Sinchang oyster habitat. M,. chungmuensis-infected oysters were found from June to November at Hwado and from June to October at Och'$\check{o}$n. Twenty five of three hundred oysters transplanted from Sinchang to Hwado were found infected with M. chungmuensis. Some abnormal eggs infected with M. chungmuensis are liberated through the gill together with normal mature eggs on the spawning and the rest remain necrotized after spawning season. The earliest known stages consist of a stem cell or primary cell, including a secondary cell in which ovoid haplosporosomes are found. During sporulation, 2 or 3 secondary are produced by exogenous budding from the first secondary cell and, each secondary cell evolves into a sporont upon the tertiary cell differentiation (enodogenous budding) ; then, haplosporosomes are formed in the young sporont. Internal cleavages involve the differentiation of one tricellular spore per sporont. The outermost spore cell contains membrane-bounded osmiophilic bodies : the middle and the inner, most spore cells contain high density cytoplasmic ribosomes. The mechanism of spore formation from the stem cell of M. chungmuensis is the simplest of the class Paramyxea known up to now.

• 한국해양학회지
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• v.24 no.3
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• pp.157-164
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• 1989

Quantitative species distribution and primary productivity of phytoplankton were studied monthly from August, 1987 to July, 1988 along with the quantitative distribution of total heterotrophic bacterioplankton and three groups of physiologically chracteristic bacterioplankton in the intertidal and subtidal waters off Kum River Estuary, Yellow Sea. A total of 121 phytoplankton taxa including 102 diatoms occurred, and cell concentration ranged from 15 to 5451 (cells/ml). The great spatio-temporal variations of the number of phytoplankton species and cell concentration well reflected the environmental differences between the intertidal and subtidal waters. Primary productivity (in Piopt, mgC/$m^3$/hr) ranged from 0.6 to 27.3. Just after the phytoplankton bloom (March) Piopt was very low in April at station 1, where amylolytic bacterioplankton also showed quite low population density. The peaks of primary productivity were not always coincided with those of phytoplankton standing crop. The ratio of Piopt's between samples well indicated the environmental differences between the intertidal and subtidal waters. Little characteristic trend was found in the scatter diagrams of phytoplankton standing crop along the population densities of total heterotrophic bacterioplankton and the three groups of physiologically characteristic bacterioplankton. In summer the phytoplankton standing crop was minimum in contrast with the high population density of bacterioplankton, which implies the influx of much allochthonous orgainc matter from Kum River. The scatter diagrams of Piopt along bacterioplankton population density revealed some phenomena there. Piopt had highly positive correlation with the population density of amylolytie bacterioplankton($R^2$=0.84) and that of lipolytic bacterioplankton($R^2$=0.70) while total heterotrophic bacterioplankton and proteolytic bacterioplankton had lesser correlations with Piopt. From the regression lines the increase of unit Piopt (mgC/$m^3$/hr) in the study area was calculated to mean the increase of $9.0{\times}10$ cells/ml and $8.0{\times}10$ cells/ml of amylolytic bacterioplankton and lipolytic bacterioplankton, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.1
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• pp.8-34
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• 2014

We reviewed foreign evaluation systems based on the macrobenthic and macroalgal communities and developed a system, composed of a set of ecological indices able to evaluate the functionality (FI, Functional Index; estimation of stability and productivity) and maturity (MI, Maturity Index; comparisons with biological parameters of natural reefs) of artificial reefs by comparing the status in the adjacent natural reefs in Korean coastal waters. The evaluation system was applied to natural and artificial reefs/reef-planned areas (natural reefs), established in the 5 marine ranching areas (Bangnyeong-Daechung, Yeonpyung, Taean, Seocheon and Buan) in the west coast of Korea. The FI ranged between 31.6 (Bangnyeong-Daechung) and 72.5% (Buan) and MI did between 53.1 (Seocheon) and 76.9% (Taean) in average. The evaluation of artificial reefs by the two indices, showed the most appropriate status in Taean. The FI between the adjacent artificial and natural reefs were in significant linear relationship ($r^2=0.83$, p=0.01). This indicated the local status of biological community may be critical in determining the functionality of the artificial reefs. We have suggested an integrative but preliminary evaluation system of artificial reefs in this study. The output from the evaluation system may be utilized as a tool for environment/resource managers or policy makers, responsible for effective use of funds and decision making. Given the importance, we need to use the options to enhance and improve the accuracy as follows: (1) continuous validation of the evaluation system and rescaling the criteria of indicators, (2) vigorous utilization of observation and experience through the application and data accumulation and (3) development and testing of brand-new indicators.