• Title/Summary/Keyword: Jinhae

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Numerical Simulation of the Formation of Oxygen Deficient Water-masses in Jinhae Bay (진해만의 빈산소 수괴 형성에 관한 수치실험)

  • CHOI Woo-Jeung;PARK Chung-Kill;LEE Suk-Mo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.4
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    • pp.413-433
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    • 1994
  • Jinhae Bay once was a productive area of fisheries. It is, however, now notorious for its red tides; and oxygen deficient water-masses extensively develop at present in summer. Therefore the shellfish production of the bay has been decreasing and mass mortality often occurs. Under these circumstances, the three-dimensional numerical hydrodynamic and the material cycle models, which were developed by the Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the oxygen depletion and also to evaluate the environment capacity for the reception of pollutant loads without dissolved oxygen depletion. In field surveys, oxygen deficient water-masses were formed with concentrations of below 2.0mg/l at the bottom layer in Masan Bay and the western part of Jinhae Bay during the summer. Current directions, computed by the $M_2$ constituent, were mainly toward the western part of Jinhae Bay during flood flows and in opposite directions during ebb flows. Tidal currents velocities during the ebb tide were stronger than that of the flood tide. The comparision between the simulated and observed tidal ellipses showed fairly good agreement. The residual currents, which were obtained by averaging the simulated tidal currents over 1 tidal cycle, showed the presence of counterclockwise eddies in the central part of Jinhae Bay. Density driven currents were generated southward at surface and northward at the bottom in Masan Bay and Jindong Bay, where the fresh water of rivers entered. The material cycle model was calibrated with the data surveyed in the field of the study area from June to July, 1992. The calibrated results are in fairly good agreement with measured values within relative error of $28\%$. The simulated dissolved oxygen distributions of bottom layer were relatively high with the concentration of $6.0{\sim}8.0mg/l$ at the boundaries, but an oxygen deficient water-masses were formed within the concentration of 2.0mg/l at the inner part of Masan Bay and the western part of Jinhae Bay. The results of sensitivity analyses showed that sediment oxygen demand(SOD) was one of the most important influence on the formation of oxygen depletion. Therefore, to control the oxygen deficient water-masses and to conserve the coastal environment, it is an effective method to reduce the SOD by improving the polluted sediment. As the results of simulations, in Masan Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $50\%$ reduction in input COD loads from Masan basin and $70\%$ reduction in SOD was conducted. In the western part of Jinhae Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $95\%$ reduction in SOD and $90\%$ reduction in culturing ground fecal loads was conducted.

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Understanding of Phytoplankton Community Dynamics Through Algae Bioassay Experiment During Winter Season of Jinhae bay, Korea (생물검정실험을 통한 동계 진해만 식물플랑크톤의 군집 변동 특성 파악)

  • Hyun, Bong-Gil;Shin, Kyoung-Soon;Kim, Dong-Sun;Kim, Young-Ok;Joo, Hae-Mi;Baek, Seung-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.1
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    • pp.27-38
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    • 2011
  • The distributions of phytoplankton assemblages and environmental factors in Jinhae Bay and their relationships were investigated to estimate the potential limiting nutrient for phytoplankton growth and community structure. In situ algal bioassay experiments were also conducted to assess the species-specific characteristics in phytoplankton responses under different nutrient conditions (control, N(+) and P(+) treatment). During the study periods, bacillariophyceae and cryptophyceae occupied more than 90% of total phytoplankton assemblages. Phytoplankton standing crops in the inner part of Masan Bay were higher than that of Jinhae Bay. The DIN:DIP ratio, pH and transparency showed the significant positive correlation with phytoplankton biomass. According to cluster and multidimensiolnal scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western part of Jinhae bay where cryptophyta species were dominated. The second group was distinguished from inner stations in Masan Bay. These stations showed low transpancy and high DIN:DIP ratio. The other cluster included the stations from the eastern part and central part of Jinhae Bay, which was characterized by the high DSi:DIP ratio and dominant of diatom species. Phosphorous (P) was limited in Masan Bay due to significantly increases in the phytoplankton abundances. Based on stoichiometric limitation and algal bio-assay in Jinhae Bay, nitrogen (N) was a major limiting factor for phytoplankton production. However, silicate (Si) was not considered as limiting factor, since Si/DIN and Si/P ratio and absolute concentration of nutrient did not create any potential stoichiometric limitation in the bay. This implies that high Si availability in winter season contributes favorably to the maintenances of diatom species.

Seawater Quality And Red Tides In Jinhae Bay:I. Relationships Between Water Quality Parameters And Red Tides

  • Lee, Kwang Woo;Hong, Gi-Hoon;Yang, Dong-Beom;Lee, Soo-Hyung
    • 한국해양학회지
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    • v.16 no.2
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    • pp.43-48
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    • 1981
  • To carry out baseline studies on monitoring systems for red tides in Jinhae bay, measurements and analyses were made on seawater samples from 15 sampling stations during 15 months from July, 1979. Water quality parameters studied are temperature, pH, DO, salinity, COD, SS, NO$\sub$3/, NO$\sub$2/, PO$\sub$4/, SiO$\sub$2/, Ca, Mg, Cd, Cu, Pb, Zn, Chlorophyll ${\alpha}$, diatoms and dinoflagellates. Multiple regression analyses were undertaken with chlorophyll ${\alpha}$, cell numbers of diatoms and dinoflagellates as the dependent variables and water quality parameters as the independent variables. The results showed that biomass, expressed as total cell numbers of diatoms and dinoflagellates, was largely influenced by COD, salinity and nutrients.

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Horizontal and vertical profiles of PCBs in sediments from southeastern coastal areas of Korea

  • Kim, Sang-Soo;Moon, Hyo-Bang;Lee, Pil-Yong;Choi, Hee-Gu
    • Journal of the korean society of oceanography
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    • v.36 no.4
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    • pp.93-100
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    • 2001
  • The concentrations of 20 congeners of PCBs were determined in surficial and dated sediments from Jinhae, Busan, Ulsan and Yeongil Bay of Korea to assess current distributions as well as historical trends. The concentration ranges of total CBs in sediments were nd-138.60 ng/g dry wt. The concentrations of total CBs were significantly different among bays in the southeastern coastal areas (Kruskal-Wallis Test, p=0.036), Showing the Order Of Busan>Ulsan>Yeongil>Jinhae Bay. Predominant PCB homologues were penta-, hexa- and hepta-CBs. The down-core distributions of PCBs showed that the highest concentrations occurred in the late 1960s, coinciding with the onset of industrialization of Korea. The compositions of PCB congeners in sediment among bays were uniform, suggesting that major sources were not changed over time.

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Study of Formation and Development of Oxygen Deficient Water Mass, Using Ecosystem Model in Jinhae, Masan Bay (생태계 모델을 이용한 진해·마산만에서의 빈산소수괴의 형성 및 발달에 관한 연구)

  • Kim, Yeon-Joong;Kim, Myoung-Kyu;Yoon, Jung-Sung
    • Journal of Ocean Engineering and Technology
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    • v.24 no.6
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    • pp.41-50
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    • 2010
  • This study established a 3D ecosystem model composed of stratification considering the topographic heat accumulation effect and river outflow, and then applied this model to Jinhae, Masan Bay. Specifically, it reenacted the formation and developmental process of ODW according to the stratification by calculating the kinematic eddy viscosity and eddy diffusion coefficient of the stratification model. The results were used as input data for the ecosystem model and compared with DO, COD, I-N, and I-P, which is the standard index of ocean water quality. As a result, it was determined that COD and T-N are third grade and T-P is second grade standards for a natural environment.

Sterols of sewage indicators in marine sediments of Jinhae Bay, Korea

  • Choi, Hee-Gu;Kim, Sang-Gyoon;Kim, Sang-Soo;Moon, Hyo-Bang;Lee, Pil-Yong;Park, Chung-Kil
    • Journal of the korean society of oceanography
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    • v.37 no.2
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    • pp.51-57
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    • 2002
  • The ${\Delta}^5$ sterols were measured in be sediments of Jinhae Bay surrounded by industrial cities to assess the sewage-derived contamination. The total concentrations of total sterols ranged from 2.03 to 19.56 ${\mu}g/g$ dry wt. The principal sterol was cholesterol with a contribution of more than 50% to total sterols. Coprostanol, providing an indication of long-term sewage loads, was found in all sediment samples and the concentrations were 0.03-3.86 ${\mu}g/g$ dry wt, accounting for 1-26% to total sterols. The cluster analysis of sampling stations indicated that the sewage-derived contamination was localized in inner Masan Bay.

Contribution and Future Direction in the Study of Aquacultural Oceanography in Jinhae Bay, Korea (진해만의 양식해양학적 연구의 업적과 미내의 과제)

  • CHO Chang-Hwan
    • Journal of Aquaculture
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    • v.4 no.2
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    • pp.129-136
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    • 1991
  • This is a review of the studies on aquaculture and its environments in Jinhae Bay, one of the most productive areas in the south coastal waters in Korea, carried out since 1960's. It's content consists of describing the outlines of, (1) a brief history of shellfish culture development and the study of oceanic environments relating to the aquaculture, (2) the oceanographic studies on the eutrophication, red tides, and the mass mortality of shellfish due to pollution and (3) the studies on forecasting aquaculture and oceanographic conditions, and on the direction of aquacultural oceanographic studies in the near future.

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Vertical Distributions of Chemical Oceanographic Parameters in Jinhae Bay in July, 1983 (1983年 7月 鎭海灣의 海洋化學指數의 水質分布에 관하여)

  • Yang, Dong-Beom;Kim, Suk-Hyun;Lee, Kwang Woo
    • 한국해양학회지
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    • v.19 no.1
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    • pp.89-93
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    • 1984
  • Vertical and horizontal distributions of chemical oceanograthic parameters were measured in Jinhae Bay in July, 1983. On the Masan-Gadeog section, high amounts of dissolved nitrates, ammonia, chlorophylla-a, and particulate carbon and nitrogen were observed in waters with low salinity. In the inner Masan Bay, high concentrations of dissolved ammonia and phosphates were shown. The C/N ratio in the surface waters was higer in the outer bay. Concentrations of dissolved inorganic nitrogen and phosphates in the surface waters seemed to be sufficient for red tides to occur.

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