• Ocean and Polar Research
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• v.44 no.1
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• pp.1-11
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• 2022

Hypoxia can affect water-atmosphere methane flux by controlling the production and consumption processes of methane in coastal areas. Seasonal methane concentration and fluxes were quantified to evaluate the effects of seasonal hypoxia in Dangdong Bay (Gyeongsangnamdo, Jinhae Bay, South Korea). Sediment-water methane flux increased more than 300 times during hypoxia (normoxia and hypoxia each 6, 1900 µmol m^-2 d^-1), and water-atmospheric methane flux and bottom methane concentration increased about 2, 10 times (normoxia and hypoxia each 190, 420 µmol m^-2 d^-1; normoxia and hypoxia each 22, 230 nM). Shoaling of anaerobic decomposition of organic matter in the sediments during the hypoxia (August) was confirmed by the change of the depth at which the maximum hydrogen sulfide concentration was detected. Shoaling shortens the distance between the water column and methanogenesis section to facilitate the inflow of organic matter, which can lead to an increase in methane production. In addition, since the transport distance of the generated methane to the water column is shortened, consumption of methane will be reduced. The combination of increased production and reduced consumption could increase sediment-aqueous methane flux and dissolved methane, which is thought to result in an increase in water-atmospheric methane flux. We could not observe the emission of methane accumulated during the hypoxia due to stratification, so it is possible that the estimated methane flux to the atmosphere was underestimated. In this study, the increase in methane flux in the coastal area due to hypoxia was confirmed, and the necessity of future methane production studies according to oxygen conditions in various coastal areas was demonstratedshown in the future.

• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.12-18
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• 2005

Typhoon Maemi landed on the southeast coast of Korea and caused a severe storm surge in Jinhae Bay and Masan Bay. The tide gage in Masan Port recorded the storm surge of a maximum of more than 2m and the area of more than 700m from the Seo Hang Wharf was flooded by the storm surge. They had not met such an extremely severe storm surge since the opening of the port. Then storm surge was hindcasted with a numerical model. The typhoon pressure was approximated by Myers' empirical model and super gradient wind around the typhoon eye wall was considered in the wind estimation. The land topography surrounding Jinhae Bay and Masan Bay is so complex that the computed wind field was modified with the 3D-MASCON model. The motion of seawater due to the atmospheric forces was simulated using a one-layer model based on non-linear long wave approximation. The Janssen's wave age dependent drag coefficient on the sea surface was calculated in the wave prediction model WAM cycle 4 and the coefficient was inputted to the storm surge model. The result shows that the storm surge hindcasted by the numerical model was in good agreement with the observed one.

• 한국해양학회지
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• v.18 no.1
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• pp.49-54
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• 1983

sediments were collected from 23 ststions in Jinhae Bay and Cd, Cr, Cu, Fe, Ni, Mn, Pb and Zn were determined by atomic absorption spectrohotometry. The concentrations of Cd, Cr, Cu, Pb and Zn in the sediments decreased gradusally with increasing distance from the gead of Masan Bay, indicating pollutant transport from industrial and municipal wastewaters. But the levels of Co, Fe, Ni and Mn showed no difference througout the bay. analysis of correlation coefficients showed that Cd, Cr, Cu, Pb and Zn in the sediments were [losely associated to one another, whereas co, Fe and Ni were so associated.

• Journal of the korean society of oceanography
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• v.31 no.2
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• pp.43-54
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• 1996

Jinhae Bay, one of the largest tidal bays on the southern coast of Korea, is an area with thick accumulations of recent, fine-grained sediments, mainly supplied from the Nakdong River. The preponderance of silt and clay particles reflects the large quantity of sediments transported in suspension. Although the clay mineral assemblage is similar to that derived from the nearby Nakdong River, relatively high concentration (3-9%) of smectite suggests some local input of fine particles from several streams around the bay or some contribution from the offshore water that may be influenced by the Tsushima Current. The content of organic matters in sediments is as high as 12%, and their C/N ratios imply that they are comprised of mixtures derived from marine plankton and terrestrial plants. $^{210}Pb$ excess activity profiles of sediment cores yield an average sedimentation rate (a 100-year time scale) of about 2-5 mm/yr, which coincides well with the long-term sedimentation rate (a 1000-year time scale) estimated from the sediment isopach map. On the basis of sediment bulk density and sedimentation rate, an annual sink of mud in the bay is estimated approximately 1.0 ${\times}$ $10^{6}$ tons per year.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.74-85
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• 2016

For the assessment of seawater exchange rates in Danghangpo bay, Dangdong bay, Wonmun bay, Gohyunsung bay, and Masan bay, which are small-scale inner bays of Jinhae bay, an EFDC model was used to reproduce the seawater flow of the entire Jinhae bay, and Lagrange (particle tracking) and Euler (dye diffusion) model techniques were used to calculate the seawater exchange rates for each of the bays. The seawater exchange rate obtained using the particle tracking method was the highest, at 60.84%, in Danghangpo bay, and the lowest, at 30.50%, in Masan bay. The seawater exchange rate calculated based on the dye diffusion method was the highest, at 45.40%, in Danghangpo bay, and the lowest, at 34.65%, in Masan bay. The sweater exchange rate was found to be the highest in Danghangpo bay likely because of a high flow velocity owing to the narrow entrance of the bay; and in the case of particle tracking method, the morphological characteristics of the particles affected the results, since once the particles get out, it is difficult for them to get back in. Meanwhile, in the case of the Lagrange method, when the particles flow back in by the flood current after escaping the ebb current, they flow back in intact. However, when a dye flows back in after escaping the bay, it becomes diluted by the open sea water. Thus, the seawater exchange rate calculated based on the dye diffusion method turned out to be higher in general, and even if a comparison of the sweater exchange rates calculated through two methods was conducted under the same condition, the results were completely different. Thus, when assessing the seawater exchange rate, more reasonable results could be obtained by either combining the two methods or selecting a modeling technique after giving sufficiently consideration to the purpose of the study and the characteristics of the coastal area. Meanwhile, through a comparison of the degree of closure and seawater exchange rates calculated through Lagrange and Euler methods, it was found that the seawater exchange rate was higher for a higher degree of closure, regardless of the numerical model technique. Thus, it was deemed that the degree of closure would be inappropriate to be used as an index for the closeness of the bay, and some modifications as well as supplementary information would be necessary in this regard.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.2 s.21
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• pp.69-79
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• 2004

This study focuses on the relationship between pollution factors around Masan, Changwon and Chinhae city considerd as main pollution sources and marine environment in Masan bay of Korea. Water quality data measured In Jinhae bay and environmental investigation data in Masan, Changwon and Jinhae cities from 1981 to 1998 were used for this study. Annual means and standard deviations of COD, DIN and DIP concentrations from 1981 to 1998 showed that both their concentration and fluctuations were higher in the inner part of Masan bay (region A) than near Somodo (region B). Sediment dredging in Masan bay had been done from 1990 to 1994. After dredging, COD concentration has been decreasing In surface layer. Also water pollution was gradually spreaded from the inner part to the outer part of the bay due to the continuous inflow of domestic sewage and industrial wastewater. In the late of 1990s, the pollution was heavier. DIN and DIP concentrations were found to be increased by establishment of industry complex and decreased by sewage treatment plant near the city adjacent to Jinhae bay, 1993. The correlation between COD, DIN and DIP changes and neighbor cities' pollution sources were calculated From 1981 to 1998, correlation coefficient (r) was over 0.8 except for the bottom of region A From 1981 to 1998, r between the DIP concentration and population was over 0.65 except for the surface of region A, and the r between the DIP and the number of factories was over 0.6 too, in region B.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3345-3350
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• 2014

We investigated to assess the relationships between the major nutrients and phytoplankton dynamics during the spring season in 2010 and 2011 at 23 stations in Jinhae Bay, Korea. The bay is divided into four different zones based on pollutant sources and geographical characteristics. Nutrient limitation (>80%) was significant in Zone II, which is located in central bay and is influenced by the water well mixed from outer bay. The limited nutrient was followed in Zone III and IV that was occupying between 17% and 83%. However, the low levels are being kept below 35% in Zone I, which is characterized by the semi-enclosed eutrophic area of Masan and Haegam bays. Based on the PCA (principle component analysis) analysis, the nitrogen (N) sources in 2010 were particularly dominant and it may be due to the water mixing and wastewater formed from bottom layers and sewage. In 2011, major nutrients including nitrogen, silicon and phosphorus were dominant in the bay and are supplied by the river discharge after rainfalls with low salinity conditions. In particular, the N nutrients being supplied in 2010 are correlated with pennate diatoms Pseudo-nitzchia spp. and is not related to the phytoplankton population densities in 2011. The present study suggests that N sources play an important role in the proliferation of diatom, and the rapid nutrient uptakes by them are potential nutrient limitation factors in the bay.

• 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.

• 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.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.161-161
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• 2009