• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.37-45
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• 2011

Seasonal variation in species composition and abundance of fish larvae assemblages in the south-western Jinhae Bay were investigated monthly in 2009. During the study period, 49 larvae species belonging to 24 families were collected. The dominant species were Clupea pallasii, Hexagrammos otakii, Konosirus punctatus, Engraulis japonicus, Parablennius yatabei, and Omobranchus elegansei. These six species accounted for 92.7% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated with the seasons. The peak number of species and individuals occurred in July and January, respectively. Principal component analysis(PCA) and correlation analysis showed that variation in monthly water temperature could act as an indicator of seasonal variation in community structure and abundance of the dominant species; in particular, those of C. pallasii, H. otakii, E. japonicus and P. yatabei corresponded with the water temperature.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.99-104
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• 2009

The species composition and seasonal patterns in marine benthic algal community at intertidal zone in Jinhae Bay were investigated seasonally throughout 2007. A total of 45 species, 6 Chlorophyta, 10 Phaeophyta, and 29 Rhodophyta, were recorded, and dominant species were Ulva pertusa, U. conglobata, Sargassum horneri, Gelidium divaricatum, Gracilaria textorii, and Polysiphonia morrowii during study periods. The number of species were differed with seasons and stations; Higher number of algal species was 42 species in winter, whereas 33 species was lower in summer. The number of algal species were higher at station 1,7,8, while the lower value was at station 2, 3 than other stations. The differences of marine benthic algal composition at each station in MDS ordination due to the physical characteristics and local topography.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.270-281
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• 2013

Hydro-acoustic surveys with scientific echo sounder were carried out to estimate the total density and distribution of the juvenile cod in Jinhae bay, Korea. The surveys were conducted 4 times from May to June using 2 frequency method (38kHz and 120kHz) and beam trawl were used to investigate the species composition. Also the catch amounts of juvenile cod were compared with the cod density estimated by the hydro-acoustic method. It was confirmed that the juvenile cod was stayed in Jinhae bay in early June and There was the relationship between catch of juvenile cod and the estimated density by hydro-acoustic survey. The number of juvenile cod was consequently about 365,000 fish (CV 12.9%) in May and 113,000 fish (CV 9.2%) in May based on the hydro-acoustic data.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.28-37
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• 2009

The diet of Pacific cod (Gadus macrocephalus) in the East Sea, Yellow Sea and Jinhae Bay was studied by analysis of stomach contents. In total, 518 individuals ranging from 15.5 to 77.0 cm standard length SL were analyzed. Prey organisms of the Pacific cod in the East Sea consistedof Caridea, Cephalopoda and Pisces, whereas In the Yellow Sea, the main food items of Pacific cod were similar to those of East Sea Pacific cod except for Cephalopoda. Interestingly, the stomach contents of Pacific cod in Jinhae Bay is mainly Pisces, which is in contrast to those of the two different coastal areas, the East Sea and the Yellow Sea. Although various species of food were eaten by smaller Pacific cod, both Caridea and Pisces were mainly taken by larger Pacific cod. Consequently, the diet of Pacific cod within acertain size is mainly influenced by prey abundance and prey-size spectrum in its habitat. Higher stomach emptiness of Pacific cod in Jinhae Bay might indicate that fully matured Pacific cod temporally stop feeding during their spawning period.

• The Journal of the Acoustical Society of Korea
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• v.26 no.1E
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• pp.33-38
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• 2007

Compressional wave velocity and shear wave velocity were measured for gassy sediments collected from Jinhae Bay, Korea. To distinguish inhomogeneities of gassy sediments, Computed Tomography (CT) was carried out for gassy sediment using CT Scanner. The cored sediments are composed of homogeneous and soft mud (greater than $8{\Phi}$ in mean grain size) containing clay content more than 50%. In depth interval of gassy sediments, compressional wave velocity is significantly decreased from 1480m/s to 1360m/s, indicating that the gas greatly affects compressional wave velocity due to a gas and/or degassing cracks. Shear wave velocity shows a slight increasing pattern from ${\sim}55\;m/s$ in the upper part of the core to ${\sim}58\;m/s$ at 320 cm depth, and then decreases to ${\sim}54\;m/s$ in the lower part of the core containing a small amount of gas. But shear wave velocity in the gassy sediments is slightly greater than that of non-gassy sediments in the upper part of the core. Thus, the Vp/Vs ratio is decreased (from 30 to 25) in gas charged zone. The Vp/Vs ratio is well correlated with shear wave velocity, but no correlation with compressional wave velocity. This suggests that low concentrations of gas have little affects on shear wave velocity. By CT images, the gas in the sediments is mostly concentrated around inner edge of core liner due to a long duration after sediment collection.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.68-75
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• 2002

This study were observed to the conditions of organic pollution applying to tile environmental assessments based on macrobenthos around the raft culture ground which became an issue by organic matter input in Jinhae Bay. Three stations, mussel farm, oyster farm and the control station on which rarely culture activities were fixed and have analyzed to the sediment characteristics and macrobenthic communities. Muddy substrates between 6.0 and 6.60 on mean grain size have prevailed to the bottom layer in all stations. The highest organic matter content of 2.8% was observed to the mussel farm while the lowest one of 1.5% was recorded on the control area. As a total, 79 species from seven phyla were identified. Comparing to shell farms, the control station have composed to more diversified community structure. In the mussel and the oyster farm, opportunistic species, living in high organic contents area, Lumbrineris longifolia, Heteromastus. filiformis in polychaetes and Corophium sinense in amphipod were dominated. As results on environmental assessment, in spite of changing to the species composition and densities seasonally, the mussel farm have recorded only to moderately polluted condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.4
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• pp.321-326
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• 2024

This study analyzed domoic acid (DA), the causative agent of amnesic shellfish poisoning (ASP), in shellfish produced in Jinhae Bay, Korea. From January 2018 to December 2020, samples were collected at least once a month from 10 sites in Jinhae bay. This included 170 mussels Mytilus galloprovincialis and 241 oysters Crassostrea gigas. Domoic acid was detected in some samples in collected 2018 and 2019; however, all levels were significantly below the regulatory level of 20 mg/g. Domoic acid was not detected until 2020.Moreover, the detection trend of domoic acid did not show a clear correlation with the shellfish species or season. Calculation of body exposure to domoic acid through shellfish consumption showed that it was below the health-based guidance values in all cases. These results can be used as basic data on domoic acid in shellfish produced in shellfish growing areas and as policy data for the supply of safe seafood. In addition, considering the possibility of changes in marine biotoxins due to changes in aquatic environments, continuous monitoring is necessary.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.621-626
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• 2002

The bacteriological and physicochemical analysis of sea water and sediments in south western part of Jinhae Bay was conducted. The samples were collected from 40 stations, which were established once a month from January to December, 2000. During the study period, the range of temperature was from 5.5 to $23.7^{\circ}C$, the concentration of chemical oxygen demand ranged from 1.20 to 1.55 mg/L, dissolved oxygen ranged from 3.7 to 9.1 mg/L, dissolved inorganic nitrogen ranged from 2.79 to 7.09 $\mu$g-at/L phosphate phosphorus ranged from 0.39 to 0.57 $\mu$g-at/L, and chlorophyll-$\alpha$g-at/L ranged from 4.28 to $9.66 mg/m^{3}$. The chemical oxygen demand, acid volatile sulfide and ignition loss of sediments in south western part of Jinhae Bay ranged from 0.04 to 0.40, from 24.23 to 35.52 mg/L and from 10.49 to $11.09\%$ respectively. The coliform group and fecal coliform MPN's of sea water in south western part of Jinhae Bay ranged from <3.0 to 1,600 MPN/1003nL (means <3.0 MPN/100 mL) and from <3.0 to 93 MPN/100 mL (means <3.0 MPN/ 100 mL), respectively. The coliform group was classified with IMViC reactions were analyzed. Two hundred eighteen strains that were obtained from sea water samples in south westen of Jinhae Bay represented Escherichia coli group, $61.9\%$; Citrobacter freundii group, $12.1\%$; Enterobacter aerogenes, $14.1\%$; and unknown, $11.9\%$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.364-372
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• 1995

On the outbreak of paralytic shellfish poisoning in April 1993 in most of shellfish harvesting areas in Jinhae Bay, Korea, to clarify the toxin production of causative organism Alexandrium species, 19 axenic clonal isolates established from the benthic resting cysts in three different stations of those culture grounds were subjected to PSP toxin analysis by HPLC. Individual toxin content per cell was highly variable among the strains isolated from a sampling area and originated from an individual cyst. Average toxin contents in those areas revealed higher values of 54-70 fmol/cell. Toxin profiles included C1/C2(epiGTX8/GTX8), GTX1/GTX4 and neoSTX as the major components, and GTX2/GTX3, GTX5, C4, dcSTX and STX as the minor or sporadic ones. neoSTX on the dominant toxins showed not only most diverse compositional changes comprising $5-54 mol\%$ ranges but also no detection on the half of the strains examined, which were implicated in arising of heterogeneity with a genetic trait within a geographical region. When average toxin composition was compared, carbamate toxins comprised large proportions of $57\%,\;54\%\;and\;67\%$ as total toxin in St. 1, St. 2 and St. 4, respectively. These results suggested that an extensive paralytic shellfish toxification in Jinhae Bay could be largely due to the production of highly potent carbamate toxins in the causative dinoflagellate Alexandrium species.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.193-200
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• 2022

We conducted a case study to determine the optimal model parameters and predictors of Long Short-Term Memory (LSTM) for the reproduction of dissolved oxygen (DO) concentration in Jinhae Bay. The model parameter case study indicated the lowest accuracy when the Hidden node=10, Epoch=100. This was caused by underfitting of machine learning. The accuracy increased as the Hidden node and Epoch increased. The accuracy was the highest when the Hidden node=80 and Epoch=100 with R²=0.99. In the bottom DO reproduction of Step 1 of the predictors case study, accuracy was highest when the water temperature was used as a predictor with R²=0.81. In Step 2, The R² value increased up to 0.92 when the water temperature and SiO₂ were used as a predictor. This was caused by a high correlation between the bottom DO and SiO₂ concentrations. Consequently, we determined the optimal model parameters and predictors of LSTM for the reproduction of DO concentration in Jinhae Bay.