• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.392-399
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• 2003

The spatial distribution and composition of the mesozooplankton community in the southeastern Barents Sea were observed at 17 stations, from 12 to 28 July 2002. Six taxa of zooplankton were found, including tintinnids, copepods, cumaceans, appendicularians, polychaetes, and barnacle larvae. Copepods were dominant, comprising 74% of the community. The copepod species Limnocalanus grimaldii, Pseudocalanus acuspes, Calanus glacialis, Calanus finmarchicus, and Microsetella norvegica, and the cumacean species Diastylis rathkei and Campylaspis rubicunda were identified. The overall mean abundance of the zooplankton was 72 indiv.l0 $\mu \textrm m^{-3}$ in the study area, ranging from 4 to 197 indiv.l0$\mu \textrm m^{-3}$. Zooplankton was more abundant at the oceanic than the coastal stations. The highest biomass measured was 97.4mg $\mu \textrm m^{-3}$, the mean biomass was 36.9 mg 10$\mu \textrm m^{-3}$, 93% of which was copepods. Pseudocalanus acuspes, C. glacialis, and C. finmarchicus predominated, accounting for 61% of abundance and 86% of biomass. Spatial distributions of the zooplankton community in the study area depended on the variations in water temperature and salinity, which were influenced by freshwater runoff from the continent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.957-965
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• 2013

This study simulated the egg vertical distribution of mackerel Scomber japonicus in Korean waters using general numerical models. All eggs were spawned naturally by raising broodfishes (May-June 2013), and the egg specific gravity was measured by a density-gradient column. CTD surveys provided environmental data (e.g., temperature and salinity) in May near Jeju Island, Korea. The egg specific gravity during the early stages ranged from 1.0203-1.0211. In general, the fertilized eggs showed a gradual decline in egg specific gravity until full development of the main organs, with a sudden increase just before hatching. Modeled egg vertical distributions were influenced more by wind speed than by egg buoyancy and vertical structure of the sea water. During calm and normal wind speeds, the eggs were distributed from the surface to 25-m depths. Under strong wind conditions (three times higher than the normal speed), the egg concentration on the surface decreased, and the egg distributional depth was deeper (~50 m).

• 한국해양학회지
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• v.14 no.2
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• pp.67-70
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• 1979

The characteristics of distribution of dissolved oxygen off the east coast of Korea were studied. The oxygen minimum layer was not clearly appeared on the vertical distribution of dissolved oxygen through the year. The dissolved oxygen content of the proper cold water of Japan Sea was 5.1-6.0ml/l which is very higher than those of the North Pacific region, and it means that the speed of transportation of a new and oxygen rich water from surface to deeper layer is relatively fast. Water masses in east coast of Korea can be classified by using of O$\_$2/-Salinity relations.

• 한국해양학회지
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• v.28 no.1
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• pp.47-51
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• 1993

Distribution of the marine cladoceran Evadne spinifera in waters adjacent to Korea was studied on the bases of samples collected during the Cooperative Study of the Kuroshio and Adjacent Regions, 1965-1974, and during the Exploitation Research of Marine Resources on the yellow Sea, September October 1992. This species was mainly occurred in August and September in the sea of Japan Distribution in the Yellow Sea was sparse. temperature and salinity ranged $23.42-28.24^{\circ}C$ and $32.11-24.20\textperthousand$, respectively. Maximum abundance of $11{\;}indiv./\textrm{m}^3$ was recorded in coastal waters of Honshu, Japan with $26.80^{\circ}C$ and $32.81\textperthousand$ water. E. spinifera was considered to be a stenothermal animal preferring high temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.572-582
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• 1994

To investigate water mass structure and DO(Dissolved Oxygen) distribution in Chinhae Bay, temperature, salinity and DO were observed in the bay in summer and winter from 1990 to 1993, and two-dimensional tidal current and parameter log($H/U^3$) were computed. Shallow water fronts in the bay were formed in summer in Kaduk channel and the central part of the bay having log($H/U^3$) values of $2.0{\sim}2.5$. Oxygen deficiency at the bottom layer in summer occurred in the western and northern part of the bay with weak tidal current, where the value of log($H/U^3$) was more than about 3.5 and $M_2$ tidal current was less than about 20 cm/s. DO concentration at the bottom layer of Kaduk channel and the central channel of the bay having the strong tidal current was more than about 3.5 mg/l. The isolines of DO concentration were nearly parallel to the isovelocity, and the concentrations correlated with the frontal location. The frontal location and DO distribution were influenced by tidal range, river inflow and meteorological conditions, and also correlated with bottom slope characteristics.

• Journal of Marine Bioscience and Biotechnology
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• v.13 no.1
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• pp.48-57
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• 2021

Vibrio species are Gram-negative basophils that are ubiquitous in seawater, increasing in number as the water temperature increases. Humans are usually infected by the consumption of contaminated seawater or seafood. V. alginolyticus infection in humans is mainly associated with infections of the skin and ears, such as acute otitis media and cellulitis. In this study, the distribution of V. alginolyticus along the coast of Jeju Island, and its relationship with water temperature, salinity, DO, and pH was investigated. The antibiotic susceptibility of the bacteria isolated was also tested. In seawater, the Daejeong area had the highest detection rate, with 13 cases (21.7%), and the Hallim area showed the lowest detection rate, with eight cases (13.3%) in. In shellfish, the Daejeong area had the highest rate, with seven cases (23.3%), and the Seongsan and Hallim areas had the lowest detection rate, with four cases (13.3%). The overall detection rate was the highest in Daejeong area, with 20 cases (22.2%), and the lowest in the Hallim area, with 12 cases (13.3%). The detection rate was highest when the water temperature was highest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.54-69
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• 2000

There are groundwater trouble by high-salinity yield inducing sea-water intrusion in Cheju Island. It is used groundwater-GIS(Well-lnfo) in the maintenance and management of groundwater in Cheju Island to grasp groundwater trouble area and cause of high-salinity yield. For 16 wells certain to yield high-salinity, we logged specific electrical conductivity(EC) and tried to get hold of freshwater and saltwater relationship. As result of distribution of $Cl^-$ by depth, it is showed up groundwater trouble by high-salinity yield in the east coastal area and the partly north coastal area. The reason of high-salinity groundwater yield are low-groundwater level by the structure of geology and low-hydraulic gradient etc. There is necessity for management to development and use of groundwater in the high-salinity area, special management area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.4
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• pp.362-371
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• 2016

The distribution patterns of Chromophoric Dissolved Organic Matter (CDOM) and the chemical characteristics of CDOM in the Seomjin river estuary were investigated in March, June and July 2012 in order to determine the spatial and temporal variability of CDOM along the salinity gradient considering the effects of mixing, nutrients and Chl a. The average CDOM values were $1.0{\pm}0.3m^{-1}$, $1.3{\pm}0.4m^{-1}$, and $1.4{\pm}0.3m^{-1}$ in March, June and July, respectively. A high concentration of CDOM (greater than $1.5m^{-1}$) was found at the head of the river which decreased towards the river mouth to as low as less than $0.5m^{-1}$. The average concentrations of CDOM increased from the dry season (March and June) to the wet season (July), and the average slope values ($S_{300-500}$), which were used as indicators of CDOM characteristics and sources, were in the range of $0.013-0.018m^{-1}$. The CDOM and $S_{300-50}$ values showed that not only the concentration of CDOM but also the chemical properties of DOM clearly changed between upstream and downstream in the Seomjin river. CDOM and FDOM showed a negative correlation with salinity ($R^2$ > 0.8), and CDOM was positively correlated with FDOM. Furthermore, the mixing pattern of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM was confirmed as conservative for all seasons. The main environmental factors influencing the concentration of CDOM were salinity (mixing) and water temperature, which meant the dilution of low CDOM seawater, was the controlling factor for the spatial distribution of CDOM. Increases in water temperature seemed to induce the production of CDOM during summer (June and July) through the biological degradation of DOM either by microbial activity or photo-degradation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.2
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• pp.105-116
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• 2000

In order to investigate the seasonal variation of watermass in the central coast of the southern sea of korea, oceanographic observation on the fishing grounds were carried out by the trainingship of Yosu University on May, Aug. and Nov. in 1998 and Feb. in 1999. The resultes obtained are summerized as follows : 1). The watermass in the fishing ground were divided into the coastal water(30.0~31.6$\textperthousand$ ), mixing water(31.7~33.4$\textperthousand$) and the offshore water(33.5~35.0$\textperthousand$) according to the distribution of salinity from T-S diagram plotted all salinity data observed on May, Aug. and Nov. in 1998 and Feb. in 1999. 2) The ranges of temperature and salinity were from 14.1$^{\circ}C$ to 18.8$^{\circ}C$ and from 32.2$\textperthousand$ to 34.9$\textperthousand$ in spring(May), from 14.2$^{\circ}C$ to 27.7$^{\circ}C$ and from 29.0$\textperthousand$ to 34.7$\textperthousand$ in summer(August), from 13.4$^{\circ}C$ to 21.3$^{\circ}C$ and from 31.45$\textperthousand$ to 34.5$\textperthousand$ in autumn(November) and from 8.2$^{\circ}C$ to 14.8$^{\circ}C$ and from 33.9$\textperthousand$ to 34.6$\textperthousand$ in winter(February), respectively. 3) The distribution of watermass in the fishing ground varied largely each seasons, but a general tendency on the distribution was obtained. That is, in spring and autumm the offshore water was distributed most widely and in summer the coastal and mixing water occupied the fishing ground but in winter the offshore water prevailed. 4) Variation of temperature and salinity were appeared between the surface and 30m in the coastal region and between the surface and 50m in the open ocaen region. Therefore, in the summer the thermocline and halocline were made between surface and 30m layer with vertical gradients of 10.5$^{\circ}C$/30m and 4.0$\textperthousand$/30m in the coastal region and in the open ocean region the thermocline and halocline were made between surface and 50m layer with vertical gradients of 13.$0^{\circ}C$/50m and 3.8$\textperthousand$/50m.