• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.200-210
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• 2007

Phytoplankton community was investigated in Asan Bay, South Korea. Samples were collected at 5 stations along Asan Bay axis during wet season from June to August, 2006. In June and July, salinity decreased especially at inside stations. Nutrients were high in June and July, however, decreased in August. We observed the community of phytoplankton including diatoms(62.8%), dinoflagellates(17.3%), cryptophytes(14.8%), euglenophytes(1.0%), cyanophytes (0.9%), chlorophytes(0.4%), and some of unidentified taxa(2.8%) during summer 2006 in Asan Bay. In June, dinoflagellates (mainly Prorocentrum sp.(29.6%)) were dominated, accounting for about 43.5% of total cell number, whereas in July and August diatoms (mainly Leptocylindrus sp.(21.4%), Chaetoceros sp.(27.6%)) were dominated occupying 69.1% and 89.9%, respectively. The results suggest that freshwater inputs affected phytoplankton community in the Asan Bay ecosystem.

• Korean Journal of Environmental Biology
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• v.22
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• pp.54-62
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• 2004

We examined the impacts of anthyopogenic pollutant (benzo〔a〕pyrene) on the growth and photosynthesis of five marine phytoplankton species (Skeletonema costatum, Heterosigma akashiwo, Prorocentrum dentatum, P. minimum, Aknshiwo sanguinea), which are dominant in Korean coastal water. After the 72 h exposure to benzo〔a〕pyrene, the dramatic decrease in cell numbers was observed in the range of 1 to 10 $\mu\textrm{g}$ L$^{-1}$ for S. costatum, P. minimum, P. dentatum, whereas for A. sanguinea and H. akashiwo at the low concentrations 0.1 to 1 $\mu\textrm{g}$ L$^{-1}$ . Among the 5 phytoplankton species, the highest growth inhibition concentration ($IC_{50}$/) was 6.20 $\mu\textrm{g}$ L$^{-1}$ for P. minimum, followed by 2.14 $\mu\textrm{g}$ L$^{-1}$ for P. dentatum, 1.68 $\mu\textrm{g}$ L$^{-1}$ for S. costatum, 0.74 $\mu\textrm{g}$ L$^{-1}$ for H. akashiwo, 0.10 $\mu\textrm{g}$ L$^{-1}$ for A. sanguinea. The five species exposed to the low concentration of 1 $\mu\textrm{g}$ L$^{-1}$ were recovered after transferring to new media, but the species exposed to the high concentrations of 10 and 100 $\mu\textrm{g}$ L$^{-1}$ were not recovered, with the exception of P. minimum. Those results indicate that the thecate dinoflagellate P. minimum is most tolerant to the chemical and the athecate dinoflagellate A. sanguinea is not. Geneyally, the cell-specific photosynthetic capacity of H. akashiwo exposed to the low concentrations of 0.1 and 1 $\mu\textrm{g}$ L$^{-1}$ was higher than that of the cells in the control, whereas the cells exposed to the high concentrations of 5 and 10 $\mu\textrm{g}$ L$^{-1}$ showed the negligible photosynthetic level by the first few days of the experiment. In the case of the cells exposed to the concentration of 5 $\mu\textrm{g}$ L$^{-1}$ , after 12 days of the experiment the photosynthetic capacity was increased toward the end of the experiment. This indicates that H. akashiwo may utilize the benzo〔a〕pyrene as a carton source for its growth when exposed to low concentrations. Results suggest that anthropogenic pollutants such as benzo〔a〕pyrene may have significant influence on the succession of phytoplankton species composition and the primary production in coastal marine environments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.105-118
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• 2000

Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

• Journal of Life Science
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• v.20 no.12
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• pp.1764-1771
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• 2010

Carthamus tinctorius L. (Compositae) is an herb primarily distributed throughout in the world. The species is regarded as ecologically important in the world. Safflower was used for medicines, as well as making red (carthamin) and yellow dyes. We have used the RAPD technique to investigate the phylogenetic relationships and genetic diversity of C. tinctorius. We obtained 123 bands from all the 26 cultivars. The average number of bands was 9.5 per primer. The genetic diversity of safflower is found among cultivars and there is a high among-cultivar differentiation. The OPC18-01 band is the specific marker for Syria cultivar, whereas no products were detected in individuals from other country cultivars. We found seven phenetic bands for determining the specific marker of cultivars with SCAR markers. Though the number of individuals sampled for analysis was small and probably not fully representative of the total available diversity in C. tinctorius, this study demonstrates that the regions (Morocco, Syria, and Turkey) of the Mediterranean Sea were more variable than other regions with the exception of India. In this result, although only simple result of RAPD is difficult to assert the center of species diversity of C. tinctorius, the regions of the Mediterranean Sea may be the most probable candidate for the origin of safflower. India was also the candidate of the center or secondary center of species diversity of C. tinctorius. RAPD markers were effective in classifying cultivar levels of safflower.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.159-171
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• 2001

Community structure, horizontal distribution, density, and ratio between nematodes and benthic harpacticoid copepods of the meiobenthos within the sediments of inner Sihwa Lake were investigated in May 1999 and May 2000. A total of 11 and 8 classes of meiobenthic animals were identified in 1999 and 2000, respectively, which were much lower than other coastal areas. The dominant animals during both sampling periods was the nematodes, followed by sarco-mastigophorans, nauplius of crustaceans, benthic harpacticoid copepods and polychaetes. These five classes of animals comprised more than 90% of total abundance of neiobenthos presented in the samples. In 2000, a lot of polychaete larvae were identified. The most abundant animal were the size that fits in 0.063 mm sieve size. Lower density was observed upper inner part of the Sihwa Lake during both sampling periods, and higher density was observed around the Sihwa floodgates. The average density between those two numbers were observed in the samples collected in the middle of the lake. Lower nematodes to betnhic harpacticoides (N/C) ratio, a relative indicator of environmental pollution, was observed to be lower around the floodgate but higher ratios were observed in the upper inner Sihwa Lake. The present study indicated that inner upper part of the lake becomes unsuitable for the meiobenthos, and the most inner upper lake was considered to be polluted.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.206-214
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• 2001

Water quality and Pollution state of Lake Chungcho were evaluated during three years from 1998 to 2000. We surveyed physicochemical parameters, and TSI (trophic state index) was calculated using TP, Chl. a, and SD (secchi disc transparency) data of growing season average. Water samples were collected bimonthly except freezing season. During the study period, total annual precipitation in 1998, 1999 and 2000 year was 1,797,1,722 and 1,345 mm, respectively. Salinity and conductivity were high($29.3{\pm}5.5\;ppt$, and $45,105{\pm}7,585\;{\mu}S/cm$) then other lagoons in the Eastern Coast of Korea. Chemocline was formed by salinity at $0.5{\sim}1.5\;m$ water depth. As a result of this, DO concentration of hypolimnion was below $3.0\;mgO_2/L$. Especially, when intense chemocline was formed, temperature of hypolimnion was higher than epilimnion. Secchi disc transparency, chlorophyll a, and COD were $1.8{\pm}0.3\;m$, $15.7{\pm}20.7\;mg/m^3$, and $3.1{\pm}0.8\;mgO_2/L$, respectively. Most of TN/TP ratios below 20, but concentration of TN and TP was high. Values of TSI ranged between 59 and 77, indicating a eutrophic condition in this system.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.419-428
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• 2013

We identified the diversity, geographical distribution, ecological characteristics of birds, trees, and flowers species designated as local government symbols as a means for understanding public awareness on biodiversity. A total of 114 species including 48 birds, 40 flowers, 36 tree species belonging to 40 orders 59 families 90 genus were designated as natural symbols. Pica pica (L.) in birds, Rhododendron schlippenbachii Maxim. among flowers, have also been designated as symbols. The tree Ginkgo biloba L. was designated with the highest frequency. Local governments located coastal area were selected bird species of the Laridae family and the tree species Camellia japonica L., of Pinaceae as their natural symbols. In contrast, local governments located inland have designated resident bird species such as P. pica and Columba rupestris (Pallas) and flower species from the Ericaceae as natural symbols widely distributed and easily observed throughout South Korea. However, many local governments have designated the same species as a natural symbol based on their size color and public appeal and popularity. The information about the popular species and their ecological traits are useful for establishing the criteria as flagship or iconic species selection and their roles in habitat conservation.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.319-326
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• 2014

Fish community was investigated in eutrophic Jeondae agricultural reservoir from April to November 2012. The food web structure of major fish species of Jeondae reservoir showed that due to serious organic pollution, the hyper-eutrophic condition with high chemical oxygen demand (COD), chlorophyll-a (Chl-a), total nitrogen (TN) and total phosphorus (TP), as estimated by stable isotope analysis. Total of 679 individuals were collected from the reservoir, and 9 species were identified. Interestingly, Lepomis macrochirus and Hemiculter eigenmanni known as less sensitive to pollution and water quality deterioration, dominated the reservoir, and their relative abundances were 38% and 27%, respectively. Further, the analysis of the stomach contents revealed that main food source of dominant L. macrochirus was high amount of zooplankton, which includes copepoda and cladocera, while Cyprinidae species mainly consumed organic particles with zooplankton preys. Stable isotope analysis also suggested that L. macrochirus, Carassiusauratus, Pseudorasboraparva, and H. eigenmanni are major zooplantivorous group in the Jeondae Reservoir.

• The Journal of Fisheries Business Administration
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• v.30 no.2
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• pp.91-105
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• 1999

본 연구는 필자가 미국 Oregon 주의 수산업사를 조사하던 중 1940년대부터 시작된 미국으로 이민 한 중국인들이 미국 서부 수산업에 미친 영향이 거대하다는 것을 발견하고, 이에 관련된 문헌을 찾아 최초 미국 서부(특히, California 주)에 이민하기 시작했던 중국 이민자들이 미국에서 수산업 활동을 시작한 배경과 그에 따른 영향 등을 살펴본 것이다. 중국인이 미국에 이민하기 시작한 배경은 두 가지가 있다. 하나는 국내적인 요인으로서 중국에서의 경제적 빈곤과 정치적 핍박이었고, 다른 하나는 국외적인 요인으로서 금캐기가 가능하다는 소식 등 미국 생활에 대한 동경이었다. 중국인의 미국 이민사에서 독특한 점의 하나는 중국 남부지 방에 위치한 광동성 지방민들이 절대적인 비중(90% 이상)을 차지하고 있다는 것이다. 가장 큰 이유는 광동성은 일찌기 외국문물이 드나드는 곳이어서 인근 광동성 지방민들은 다른 지방민보다 외국소식을 쉽게 접할 수 있었기 때 문이었다. 미국에 도착한 광동성 지방민들은 쉽게 직업을 구할수 없는 처지이 되자 그들이 익숙하게 알고 있는 바다생활에 뛰어들었고, 마침내는 미국 서부에서 진취적인 어업인이 되었다. 따라서 서부에서 최초의 상업적 어업인이 되었으며, 미국 서부에서 시작한 중국인의 수산업은 점차 다른 주로 퍼져 나갔다는 기록은 중국인이 미국 전역에서 최초의 상업적 어업인이었음을 알게 한다. 최초의 중국인 어촌은 1854년 San Francisco의 Rincon Point에 세워졌으며, 25척의 어선과 150여명의 주민이 살았다. 그들이 사용한 어구ㆍ어업은 통발, 정치망, 선망, 낚시, 연승 등이었으며, 중국풍의 어선과 어구를 직접 만들어 새우, 철갑상어, 대구, 우럭, 넙치, 게, 가재, 전복 등을 어획했다. 1888년에는 San Francisco 전역에 20개의 어촌이 형성되었고, 2천여명의 어업종사자가 있었다. 1900년부터는 점차 그 수가 줄기 시작하였다. 가장 크고 오래 지속된 어업은 새우어업은 1860년대부터 1940년 중반까지 계속되었으며, 이 어업에 의해 새우가 인근 지역의 보편적인 식품으로 자리하게 되었다. 인디언에 의해 단순한 장식품으로 사용되던 전복은 중국인에 의해 그 맛이 알려지게 되었고, 유럽이나 미국 동부로 팔려 나갔다. 상어 또한 중국인에 의해 먹기 시작하였으며, 내장에서 뺀 기름이 사용되기 시작하였다. 게를 잡기 위한 통발과 시장형성으로 San Francisco부두의 많은 부분이 차지되었다. 1880년대부터 시작된 해조류의 채취는 처음에는 인디언들에 의해 시작되었으나, 곧 중국인들에 의해 본격화되었다. 광동성 지방민들의 초속식품의 하나인 오징어를 잡기 위해 중국인들은 배를 만들어 야간에 횃불을 밝혔다. 오징어는 곧 San Francisco 주민은 물론 태평양 연안주와 미국 전역에 있는 중국식당에서 수요가 지속되었다. 중국인들은 1849년부터 연어를 상업적으로 잡기 시작하였으며, Washington주에서 시작되어 Oregon, British Columbia, Alaska로 퍼진 통조림 공장은 주로 중국인의 노동력에 의해 운영되었다. 위와 같이 중국인들이 미국 수산업 분야에서 크게 활동하자 미국인들은 그들의 수산업 활동을 제재 또는 통제하고자 일정한 납세를 명시한 각종 법률, 특히 The Chinese Exclusion Act 등을 제정하였다. 미국 서부에서 중국인의 수산업은 미국인의 법적 제재, 중국인의 다른 직업으로의 이직 등으로 1940년대를 끝으로 막을 내렸다.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.265-271
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• 2021

Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.