• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.92-92
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• 2003

본 연구는 부착규조류에 따른 부착성 요각류 Tigriopus japonicus의 nauplius 생산력을 알아보기 위하여 실시하였다. 실험에 사용된 T. japonicus는 부산 동백섬 부경대학교 수산과학연구소 부근에 있는 tidal pool에서 동물성부유생물망으로 채집하였다. 먹이생물로는 부경대학교 한국해양 미세조류 은행에서 보관중인 부착규조류 중 중형종인 Caloneis schroder를 대표종으로 이와 크기가(14.8~27.5$\mu\textrm{m}$) 유사한 종들을 대상으로 형태를 현미경 하에서 관찰하고, 지역과 분리일자 등을 고려하여 유사종을 선별한 후 최종적으로 종의 유전적 유사성을 밝히기 위하여 RAPD-PCR (random amplified polymorphic DNA polymerase chain reaction)을 실시하였다. 이 중 Caloneis schroder와 유전적으로 유사성이 낮은 Navicula spp. (KMCC B-245, 393, 394, 581) 4종을 선별하여 T. japonicus의 먹이로 사용하여 포란한 암컷의 nauplius 생산력을 3반복 조사하였다. Genomic DNA는 대부분의 종에서 성공적으로 검출되었으며, 종에 따라 PCR 증폭산물이 나타나지 않은 경우도 있었으므로, PCR 산물이 나타난 종에 대해서만 분석하였고, 증폭된 DNA band는 대부분 크기 0.5~2.0kb 범위에서 나타났다. 실험에 사용된 부착규조류 간의 유사성을 알아보기 위하여 similarity matrix를 분석한 결과 F값의 범위는 0.00에서 1.00까지 였으며, Caloneis schroder와 유사성이 낮은 종들에 비하여 유사성이 높은 종들이 더 많이 나타났다. 이들을 먹이로 하여 포란한 T. japonicus의 실험구별 nauplius 평균 개체수를 살펴보면, KMCC B-394가 255.7마리로 가장 높았던 반면 KMCC B-581가 29.7마리로 가장 낮았다. 그 외 KMCC B-245가 120.0마리, KMCC B-393가 76.0마리, Caloneis schroder가 32.3마리 각각 나타났다. 이와같은 결과를 볼 때 T. japonicus의 nauplius 생산력은 규조 종에 따라 큰 차이가 있는 것으로 판단된다.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.15-22
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• 2008

The role and distribution of fresh water algae was surveyed at Wangdeungjae Wetland of Mt. Jiri, a high mountain swampy land. Mean environmental factors were as follows; temperature was $17.6^{\circ}C$, pH was 6.3, conductivity was $24.6{\mu}S/cm$, TN was 0.6 mg/L, TP was 0.09 mg/L, and Chl-a was $11.9{\mu}g/L$, respectively. Algae were appeared 159 species(Chlorophyta 87, Bacillariophyta 56, Euglenophyta 11, and Cyanophyta 5). Desmid of Chlorophyta was 56 species, and dominant species was Aulacoseira distans of Bacillariophyta. To analyze food chain of the water ecosystem, we performed analysis of tadpole's stomach captured in the wetland. Tadpoles ingested mainly algae, and Aulacoseira distans was found in most quantity. Based on this study, algae take role of the primary producer as well as the prey of higher level predators(e.g. tadpoles) in the water ecosystem of Wangdeungjae Wetland.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.160-160
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• 2020

조류는 계절별 기상 및 수질 조건에 따라 규조, 녹조, 남조의 발생 및 천이가 이루어지는데 최근 기후 변화로 인해 출연종 별 발생 및 천이의 시기 또한 빨라지고 있다. 이 중 남조류의 경우 초여름에 발생하여 급격한 증식으로 대발생되어 녹조현상을 야기하고 이는 해당 수역의 생태계 파괴, 그 이외에도 사회적, 경제적, 환경적인 측면에서 많은 문제를 유발한다. 하천·호소의 조류의 발생과 거동에 대한 이해와 효과적인 대응책 마련을 위하여 현상에 대한 모니터링이 선행되어야 하지만 기존 조사방식은 점, 선 단위의 간헐적 측정을 통해 진행되고 있어 많은 인력과 시간이 필요로 하고 있는 실태이다. 현재 이에 따른 문제 해결을 위한 하천·호소의 원격탐사 기법을 이용한 조류의 발생 및 거동에 대한 모니터링 연구가 많이 진행되고 있다. 본 연구에서는 초분광 영상을 이용한 원격 탐사 모니터링을 위한 선행연구를 위해 400-1000 nm에서 NIR(visNIR)파장을 분석할 수 있는 초분광 카메라 CORNING사의 micro HSITM 410 shark와 영상 흔들림 보정을 위한 DJI사의 로닌-MX를, 이용하여 현재 녹조류, 남조류 5종의 배양액과 방사보정을 위해 99% 반사율의 반사판과 함께 촬영하여 영상을 수집하였다. 수집된 영상을 통하여 방사보정 및 해당 Base 제거를 통한 조류의 분광 정보 추출 과정을 통해 조류별 분광 정보를 추출, 분석하여 해당 조류의 분광특성을 파악하고 기초 라이브러리를 구축하여 제시함으로 추후 하천·호소에서의 초분광 영상 기반 원격탐사 모니터링에 적용하고자 한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.152-163
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• 2001

Based upon the sedimentological, geochemical and micropaleontological analyses of two sediment cores from the Antarctic Peninsula (AP), three distinct lithological units can be recognized: (1) ice-proximal an/or ice-distal diamictons in the lower part of the cores, accumulated just seaward of the grounding line of the ice shlef until 11,000 yrs BP; (2) diatomaceous mud between 6,000 and 2,500 yrs BP in the middle part, resulted from a large influx of organic materials by enhanced production of open marine condition; (3) diatomaceous sandy mud since 2,500 yrs BP, characterized by an increase in sand content and decrease in TOC and diatom abundance in the lower layers, which reflects the formation of more extensive and seasonally persistent sea ice. Based on the C-14 radiocarbon dating, the sub-ice shlef deposition of the diamicton on the AP western shelf completed around 11,000 yrs BP. Colder condition was reinstated between 12,800 and 11,600 BP with a dropin TOC content and diatom abundance, which is coincident with the Younger Dryas event in the North Atlanticregion. At this time, the ice shelf, that is now absent in the study area, appears to advance as evidenced by an abrupt increase in sea-ice taxa. A climatic optimum is recognized between 9,000 and 2,500 BP, coincide witha mid-Holocene climatic optimum 'Hypsithermal Warm Period' from the other Antarctic sites. During this time, diatomaceous mud accumulated by a large influx of organic materials by enhanced production occurred in openmarine condition. Around 2,500 BP, diatomaceous sandy mud reflects the formation of more extensive and seasonally persistent sea ice, coincident with the onset of the Neoglacial in the Antarctic. Our results provide evidence of climatic change from the Antarctic Peninsula`s western shelf that helps in determining the existence and timing of Holocene milennial-scale climatic events in the Southern Hemisphere.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.531-537
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• 2012

The information about the physicochemical environments, the species distribution and community of the epilithic diatom cells in Pyengchang river and inflow streams of Gangwon-do were studied for assessment of biological water quality from June 2008 to October 2010. Total 112 diatom taxa were identified with 2 orders, 9 families, 26 genera, 95 species and 17 varieties. Among the total taxa identified, 13 taxa, 52 taxa and 15 taxa represented the family Achnanthaceae, Naviculaceae and Bacillariaceae, respectively. The pH values of the water was found to be neutral to alkaline due to the limestone grounds of Pyengchang river and inflow streams. The 13 taxa including Epithemia adnata, belonged to alkaline-water diatoms, and three species - Cymbella japonica, Eunotia major and Fragilaria capitellata - are known to be acidic-water species. The species, Hannaea arcus, known as a cryophilic and mountain periphyton was identified at IF2, IF3 and IF4 in low water temperature environments at high altitudes, being a dominating species in P1 and IF1. Four saproxenous species - Achnanthes convergens, Cocconeis placentula var. lineata, Cymbella turgidula and Hannaea arcus - were dominant at some sampling sites. For biological water quality assessment, IF2, IF3 and P3 showed low water quality class. The values of DAIpo and TDI were 10.6 ~ 98.0 and 13.8 ~ 94.2, respectively. Therefore, biological water quality in Pyengchang river and inflow streams was relatively desirable.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.257-264
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• 2006

In order to evaluate the application of Algae Online Analyzer (AOA), an instrument of automatic measurement of chlorophyll a concentration, was tested and compared with the acetone extraction method on the basis of microscopic counting of phytoplankton in field water (Paltang Reservoir). We simultaneously conducted AOA operation and extraction method with the same water sample, to compare both results of chlorophyll a measurement. Phytoplankton were enumerated by inverted microscope with the Sedgwick-Rafter chamber, and classified into the genus or species. According to the AOA measurement, the diatom most (83.6%) strongly contributed to the total chlorophyll a concentration, followed by chlorophyceae> cyanophyceae>cryptophyceae. Overall, the results of both AOA and extraction method showed a similar trend and significant correlation (r=0.87, n=302, p<0.001), however, there were some differences according to the season and species. In particular, the relationship between AOA Chl-a density of the diatom (r=0.73, p=0.010) and cyrptophyceae (.=0.83, p=0.00154) were siginificant, while chlorophyceae (r= -0.13) and cyanophyceae (r= -0.16) showed no clear relationship during the study period. Although we can not fully understand why there was difference between both mothods, AOA application for alarming algal bloom and water quality management during the algal bloom appears to be very relevant. However, the further study or technical upgrade of AOA measurement is required, especially in the case of low density of phytoplankton or species-specific measurement.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.268-286
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• 2018

The eutrophication and algal blooms by harmful cyanobacteria (CyanoHAs) and freshwater redtide (FRT) that severely experiencing in typical regulated weir system of the Nakdong River are one of the most rapidly expanding water quality problems in Korea and worldwide. To compare with the factors of rainfall, hydrology, and dominant algae, this study explored spatiotemporal variability of the major water environmental factors by weekly intervals in eight weir pools of the Nakdong River from January 2013 to July 2017. There was a distinct difference in rainfall distribution between upstream and downstream regions. Outflow discharge using small-scale hydropower generation, overflow and fish-ways accounted for 37.4%, 60.1% and 2.5%, respectively. Excluding the flood season, the outflow was mainly due to the hydropower release through year-round. These have been associated with the drawdown of water level, water exchange rate, and the significant impact on change of dominant algae. The mean concentration (maximum value) of chlorophyll-a was $17.6mg\;m^{-3}$ ($98.2mg\;m^{-3}$) in the SAJ~GAJ and $29.6mg\;m^{-3}$ ($193.6mg\;m^{-3}$) in the DAS~HAA weir pools reaches, respectively. It has increased significantly in the downstream part where the influence of treated wastewater effluents (TWEs) is high. Indeed, very high values (>50 or $>100mg\;m^{-3}$) of chlorophyll-a concentration were observed at low flow rates and water levels. Algal assemblages that caused the blooms of CyanoHAs and FRT were the cyanobacteria Microcystis and the diatom Stephanodiscus populations, respectively. In conclusion, appropriate hydrological management practices in terms of each weir pool may need to be developed.

• Journal of the Mineralogical Society of Korea
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• v.19 no.3 s.49
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• pp.163-169
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• 2006

Mineralogy and geochemistry of the sediment core from the seamount (2710 m below the sea level) just south of the Antarctic Polar Front were examined to draw paleoceanographic information in glacial-interglacial cycles. Smectite was most abundant clay mineral associated with illite and chlorite. Its content was slightly higher below 170 cm, suggesting a boundary between isotope stage 4 and 5. Si, Zr, Cs, Th, REE, $K_{2}O$, and $Al_{2}O_{3}$ show complete antithetical distribution with respect to $CaCO_{3}$ through the core. $SiO_{2}$ maxima and $CaCO_{3}$ minima at depths of 24, 136, and 176 cm are probably correlated with massive influx of ice-rafted debris during the advance of Antarctic ice shelves. Ni, Cu, and Ba show rather little correlation with $SiO_{2}$, suggesting their relation to biogenic debris, precipitation from seawater, or hydrothermal input. Particularly, Ba maxima tend to lag $10{\sim}20cm$ after $SiO_{2}$ maxima, probably due to rapid increase of productivity following deglaciation.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.361-372
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• 2017

This study described the spatial distribution of dinoflagellate cyst assemblages in the Ulsan Coastal Waters (UCW). Surface sediment samples from 15 stations revealed the occurrence of 33 species involving the Groups Protoperidinioid (51.5%), Gonyaulacoid (30.4%), Calciodineloid (9.1%), Gymnodinioid (3.0%), Diplopsallid (3.0%) and Tuberculodinioid (3.0%). The recorded cyst abundance in the UCW recorded was low ($260{\sim}1,680cysts\;g-dry^{-1}$) compared to Korean coastal waters. The abundance of heterotrophic cysts is higher in the Ulsan harbour and northwestern parts of UCW with eutrophic areas, however autotrophic species are more prevalent in the southern parts with open sea environments. The dinoflagellate cyst assemblages in the UCW were characterized by the dominance of Gonyaulax scrippsae, Protoperidinium sp. (Brigantedinium sp.), and Gonyaulax spinifera complex. The advent of the toxic dinoflagellate, Pyrodinium bahamense var. bahamense was recorded for the first time in the East-south sea of Korea. Therefore, as a result of ongoing monitoring and management for new toxic dinoflegallates from tropical or subtropical regions, analysis of dinoflagellate cyst assemblages in the UCW has been deemed necessary.

• 한국해양학회지
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• v.26 no.1
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• pp.24-37
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• 1991

Marine benthic diatoms and environmental factors were studied at 60 sites on the Mangyung-Dongjin tidal flat of the west coast of Korea. Sediment samples were taken quantitatively from the upper 5 mm layer to obtain a representative estimate of the epipelic and epipsammic cell concentration. Surface sediments taken simultaneously with the quantitative diatom samples were analysed for the grain size. Exposure duration of study sites were calculated by the tide data recorded at Kunsan Outer-Harbour. Coarse sediments dominated mainly on the offshore coastal and lower tidal flat, whereas fine sediments occurred on inner and higher tidal flat. Total 371 diatom taxa were collected and the genera represented by a great number were Navicula and Nizschia. The 16 abundant species occupying more than 1% of total cell number are of the following: Paralia sulcata, Navicula sp. 1, Navicula arenaria, Cymatosira belgica, Amplora holsatica, Amphora coffeaeformis, Achnanthes hauckiana, Rhaphoneis amphiceros, Thalassionema nitzschioides. Navicula sp. 2, Dimeregramma minor, Amphora sp. 1, Cyclotella atomus, C, striata, Nitzschia kuetzingiana, Stephanodiscus sp. 1. The distribution pattern of these dominant species are described in relation to the habitat condition. Most of these species showed high densities in fine sediments. However, they occurred even silty sand and sandy sediments in low abundance. The epipsammic forms belonging to the Araphidineae and Monoraphidineae were restricted on the lower tidal flat. The typical species found in coarse sediments were: Cocconeis sp. 1, Opephora martyi, Amphora sabyii, Dimeregramma minor var. nana, Fragilaria virescens var. oblongella, F. virescens, Cocconeis grata. The higher tidal flat consisting of fine sediments showed relatively higher cell numbers than the lower tidal flat. River mouth region was the highest in abundance.