• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.461-475
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• 2020

This study was conducted in the southwestern area of Korea using a neuston net in September (14 stations) 2017 to understand the environmental factors affecting neustonic zooplankton. Temperature, salinity, chlorophyll a concentration, suspended solids, and microplastics were included as environmental factors. Based on the density of the copepods, the study area was divided into three regions: the Seomjin River water influence area, the frontal mixing area, and the warm water affected area (Jeju warm current and Tsushima warm current). In the latter two areas, the major species were Pontella chierchiae, Canthocalanus pauper, and Oncaea spp. Also, neustonic zooplankton showed a significant relationship between the density of phytoplankton and microplastics in the frontal mixing area, and temperature and suspended solids in the warm water affected area, respectively (p<0.05). This indicates that microplastics can affect the offshore zooplankton community.

• Korean Journal of Ichthyology
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• v.8 no.2
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• pp.47-56
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• 1996

Hydrography of the Korea Strait was influenced by the various water masses such as Korean coastal water, East Sea cold water, and Tsushima Current. Anchovy larvae were frequently found in the area influenced by the Tsushima Current. Anchovy appeared in all seasons and were most abundant in summer. Anchovy was more abundant in the middle layer(30~70m) than the surface layer in spring and summer and was little in the deeper layer beyond the depth of 100m. It was most abundant in the surface layer in autumn, and decreased toward the deeper layer. They were more abundant in the middle layer(30~50m) than in the surface layer and the bottom layer in winter. Anchovy was most abundant in the depth of 30m to 70m during the day time, however it was more abundant in the surface layer during the night time. Although vertical distribution patterns of abundance varied seasonally and diurnally, most of the larval anchovy distributed in the upper layer within the depth of 100m and in the upper layer above the thermocline in summer and autumn.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.333-342
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• 2018

In order to manage and rebuild fishery resources, the fishing effort should be controlled effectively. Especially in the setting up of the proper level of fishing efforts, economic standards as well as biological standards must be carefully considered to promote the sustainable and economically viable development of fisheries. This study is aimed to estimate optimal fishing effort of giant octopus by combo fishing which uses longline in Gangwon with statistical data. The result showed that current fishing effort is 28% higher than $E_{MEY}$. Unit fishing cost for each voyage will be 27% lower and unit fishing profit will be 17% higher than the current situation when the fishing effort meets $E_{MEY}$. Although current fishing effort is similar to the $E_{MSY}$, current catching is 16% higher than MSY and 22% higher than MEY.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.567-574
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• 2022

Immunostimulating effects of fucoidan administration to rockfish Sebastes schlegelii at a concentration of 20 g/kg of diet were evaluated under high water temperature condition. The oral administration of fucoidan mixed with feed at a concentration of 20 g/kg of diet for 2 weeks increased the interleukin 1β gene in the intestine and kidney of fish by 5.7 and 6.3 times, respectively. In addition, when the water temperature was gradually increased from 24 to 31.4℃ for 2 weeks, LT₅₀ delayed by 24 h in the fucoidan treated group compared to that in the control group, and mortality also reduced. Streptococcus iniae infection at a concentration of 1.50×10⁰ CFU/fish at 28℃ delayed LT₅₀ by 12 h in the fucoidan-treated group. Furthermore, the overall survival rate was 0% in the control group and 20% in the fucoidan-treated group. This study confirmed the applicability of dietary additives such as fucoidan as an immune activator of rockfish under high temperature condition.

• (The) Research of the performance art and culture
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• no.41
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• pp.321-352
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• 2020

Donghaean Byeolsingut itself reflects the ideals and dreams of seaside life. Imagination and interest in water are fully reflected in Donghaean Byeolsingut as a living in a seaside town. For the beach people, water is the foundation of life and the object of fear. It is the water of life and the water of death. It projects the whole process of life into the imagination created by the world encompassed by the sea. The beach's imagination is an existential insight into the whole process of life and a reflection of existential agony. At Poongeoje, the villagers hope for a specific blessing from God. People are free only when God's retribution comes down. The villagers feel free because of the virtue of the shaman's blessing. Individual trauma is experienced to a certain extent by gaining mental freedom. It can be said that the state of aesthetic pleasure experienced by creating an art work by itself and the nature of aesthetic pleasure experienced through Pungeoje and Byeolsingut are not different. The prototype of Poongeoje is a free spirit, and a religious aesthetic to strengthen the free spirit is the core of the aesthetic.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.19-30
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• 2019

To investigate the characteristics of seasonal environment and phytoplankton community structure in the coastal area of Dokdo, a survey of Dokdo around waters was conducted during the four seasons. Phytoplankton of 4 phylum 72 species in four seasons were collected in Dokdo around water. The seasonal mean abundance of phytoplankton were $3.32{\times}10^4cells\;L^{-1}$ in winter, $1.04{\times}10^4cells\;L^{-1}$ in spring, $0.28{\times}10^4cells\;L^{-1}$ in summer, and $4.86{\times}10^4cells\;L^{-1}$ in autumn in Dokdo around water. During winter, the diatoms Chaetoceros spp. had dominated. During spring, when the nutrients in the euphotic layer were depleted, the nano-flagellates and Cryptomonas appeared at surface layer. In summer, the abundance of phytoplankton was relatively low, which lead to occurrence of diatoms such as genus of Chaetoceros, Rhizosolenia, and Skeletonema. In autumn, Pseudo-nitzschia spp. was the most dominant species and tropical species such as Amphisolenia sp. and Ornithocercus magnificus were observed, implying that they may have introduced within warm water current such as Kurosiwo Current. Therefore, although natural phytoplankton communities in the vicinity water of Dokdo are mainly influenced by Tsushima Warm Current branched Kurosiwo Current, their population dynamics was affected on the spatio-temporal change of physicochemical factors by short-term wind events, namely "island effect". Long-term survey research is needed to facilitate food-web response in marine ecosystem associated with phytoplankton biomass and physicochemical factors including the warm water current in oligotrophic offshore water of Dokdo, which may have significant role for sustainable use of Dokdo.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.5
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• pp.482-492
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• 2015

Ground-based measurements were conducted from January 6 to 12 of 2015 for understanding characteristics of nitrogen containing carbonaceous aerosols as 16 amino acids at the Mokpo National University, Korea. The detailed amino acid components such as Cystine ($(SCH_2CH(NH_2)CO_2H)_2$) and Methionine ($C_5H_{11}NO_2S$) and their sources were analyzed by High-Performance Liquid Chromatography with Fluorescence Detection (HPLC-FLD) for behavior of secondary products in particulate matter. In addition, organic carbon (OC) and elemental carbon (EC) based on the carbonaceous thermal distribution (CTD), which provides detailed carbon signature characteristics relative to analytical temperature, and water soluble organic carbon (WSOC) by total organic carbon (TOC) analyzer were used to understand the carbon compound behaviors. The backward trajectories were discussed for originations of carbonaceous aerosols as well. Different airmasses were classified with the amino acids and OC thermal signatures. The results can provide to understand the aging process influenced by the long-range transport from East Sea area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.4
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• pp.404-409
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• 1999

The in situ target strengths of, maurolicus muelleri were measured by the split beam echo sounder system at the frequency of 38kHz.Target strengths were measured during the night time in order to obtain the pure separated echoes from the scattered individual. And also it was to establish reasonable threshold due to taking the signals like as the planktons and etc.Since Maurolicus muelleri is a typical micronektonic fish, they mainly consisted of deep scattering layers(DSLs), and had a vertical migration perrodically during daytime and at night.We found that the Maurolicus muelleri occupied about 99% of total catch. Total length ranged from 4.5 to 5.7cm with a mean of 5.2cm and a standard deviation of 0.22cm.The target strengths of Maurolicus muelleir ranged from -60.4 to - 52.7dB and -59.2 to - 52.5 dB in the water layer of 10~30m and 30~50m depth, perspectively. Mean target strength was -57.1dB/fish and -28.5dB/kg. The target strength had the relation with the total length of the fish as, TS=20logL-71.4.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.619-625
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• 2013

We investigated yearly fluctuation of the fish species composition of beam trawls off Maemuldo in the east southern sea of Korea, from March 2007 to November 2009. A total of 75 fish species were collected during the period. The number of fish species accumulated amounted to 54, 64 and 75 species in 2007, 2008 and 2009, respectively. The number of newly occurring species increased with time. The number of expected resident species in Maemuldo was estimated as 9 species including Conger myrister, Okamejei kenojei and Pholis nebulosa, each of which appeared more than 14 out of a total 27 times. Cluster analysis showed that the years 2007 and 2008 were closely clustered, while the year 2009 was distantly clustered with 2007 and 2008. This may be due to the high catch ratio of Clidoderma asperrimum in 2009 alone, when a low water temperature phenomenon was observed unlike the situation in 2007 and 2008.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.121-129
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• 2016

The distribution of eggs and larvae of mackerel, Scomber japonicus was examined in the coast of Jeju island, Korea in spring from April to May in 2013 and May to June in 2014. In the monthly variations of mean abundances, as a whole, mackerel eggs were observed abundantly in April, 2013, and mackerel larvae were observed abundantly in June, 2014. Especially, high densities over $5,000ind./1,000m^3$ of mean eggs abundances were observed in the eastern part of Jeju Island where is water temperature was over $18^{\circ}C$. It can be inferred that these areas were major spawning grounds of mackerel around Jeju island, and that it may be caused by influences of the Tsushima warm current.