• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.3
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• pp.265-272
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• 2002

Spatial distribution of Phytoplankton Pigment Concentration (PPC) and Sea Surface Temperature (SST) around the East Korean Warm Current (EKWC) was described, using both Coastal Zone Color Scanner (CZCS) images and Advanced Very High Resolution Radiometer (AVHRR) images in May, 1980. Water mass in this region can be classified into five categories in the horizontal profile of PPC and SST, nLw (normalized water-leaving radiance) images: (1) coastal cold water region associated with concentrations of dissolved organic material or yellow colored substances and suspended sediments, (2) cold water region of thermal frontal occurred by a combination of phytoplankton absorption and suspended materials, (3) warm water overlay region by the phytoplankton absorption than the suspended materials; (4) warm water region occurred by the low phytoplankton absorption, and (5) offshore region occurred by the high phytoplankton absorption. In particular, the highest PPC (>2.0 mg/m^3) area appeared in the CZCS and AVHRR images with a band shaped distribution of the thermal front and ocean color front region, which is located the coastal cold waters alonB western thermal front of the warm streamer of the EKWC. In this region, the highest PPC occurred by a combination of the high absorption of the phytoplankton (443 nm) and highest reflectance of suspended materials (550 nm). Another high PPC ($\simeq$$6\;mg/m^3$) appeared in the warm water overlay region inside warm streamer. High phytoplankton pigment concentration of this region was corresponding to the short wavelength of 443 nm, which represented phytoplankton absorption of the CZCS image.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.191-193
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• 2003

Temporal and spatial variability of phytoplankton pigment concentrations around the Korea Peninsula was described, using the monthly mean composite images of the SeaWiFS (Sea-Viewing Wide Field-of-View Sensor). The high pigment concentrations appear in the spring and fall in the East Sea The spring bloom in the southern regions (in April) occurs one month in advance in comparison with tint in the northern regions (in May). In summer season, the pigment concentrations are low all over the region in the East Sea And the high pigment concentrations exist yearly around warm stream along the coast of the East Sea, and in the coast of the West Sea and South Sea In particular, the high pigment concentrations linking near the mouth q the Yangze River to coast of South Sea in Korea appear during August to December.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.198-199
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• 2001

식물플랑크톤의 증식에 영향을 미치는 요인 중에서 온대해역에서 가장 현저한 것은 수주의 연직혼합의 깊이이다. 식물플랑크틀이 물의 혼합에 의하여 연직적으로 아래에 이송되어, 그 깊이까지의 수주내의 전광합성량과 전호흡량(일차 생산자)이 같아질 때의 깊이를 Critical depth(CRD)라고 한다. CRD의 개념은 Gran and Braarud (1935)에 의해 제창되었고, Sverdrup(1953)에 의하여 수치모델로서 발전했다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.215-216
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• 2002

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.2
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• pp.71-77
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• 2015

High-Performance Liquid Chromatography (HPLC) is a widely used method for measuring the concentration of chlorophyll a as an indicator for estimating phytoplankton biomass and primary production and also for identifying carotenoids to determine phytoplankton composition. However, tissue grinding procedure requires a lot of time and experience in the analysis of multiple sample. Accordingly, we measured the concentrations of photosynthetic pigments before and after the grinding, in order to understand the grinding effects on the quantitative analysis of chlorophylls and carotenoids using samples from southwestern East Sea. When tissue grinding procedure was omitted, we found that Chl a concentrations were underestimated up to 45% in average. Also, concentrations of Zeaxanthin, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxanthin, biomarkers of pico and nano-size phytoplankton, were underestimated up to maximum 77~85% without grinding. We found that the smaller the phytoplankton, the bigger underestimation of their biomarker pigments concentration is likely to happen due to the incomplete extraction. Thus, tissue grinding procedure should be included for HPLC analysis in all cases, to prevent the underestimation of not only Chl a but also carotenoids pigments.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.99-106
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• 2020

To investigate effect of variation in physiochemical conditions due to river discharge on phytoplankton, field surveys were conducted in the Seomjin and Yeongsan River estuaries from April to November 2016. The concentrations of DIN and DSi in Seomjin River estuary were gradually low as distance from upstream. On the other hands, the concentrations of DIN and DSi in Yeongsan River estuary were critically high at upstream, due to which is characterized as semi-enclosed eutrophic area. A total of 12 phytoplankton pigments were analyzed, and the distribution of each taxa was investigated using indicator for each phytoplankton taxa. Fucoxanthin, an indicator pigment of diatoms, showed an average of 0.61±1.00 ㎍ l^-1 and 0.76±1.22 ㎍ l^-1 in the Seomjin and Yeongsan River estuaries, respectively. Concentration of fucoxanthin was more than twice that of other pigments except chlorophyll a., indicating that diatoms were dominant taxa. Peridinin, an indicator pigment of dinoflagellate, showed some similar tendency to the microscopic observation, but mismatch results were also present, indicating a technical limitation of pigment analysis. Chlorophyll b, alloxanthin, and zeaxanthin, which are indicator pigments of green algae, cryptomonads, and cyanobacteria, were detected in both estuaries even though those taxa were not detected in microscopic observation. This indicates that the two estuaries were affected by freshwater species. Here, we can suggest that phytoplankton composition in estuary was directly influenced by the inflow from upstream. In particular, the phytoplankton population dynamics in Yeongsan River estuary was greatly associated with a large-scale artificial dyke, especially in summer rainy season. On the other hands, the seasonal and horizontal distribution of phytoplankton in Seomjin River estuary has changed along the salinity gradients and inflow-related changes.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.3
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• pp.40-48
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• 2007

We analyze relation between phytoplankton and marine environment based on data such as water temperature, phytoplankton, zooplankton, nutrient collected from the southern coast of Korea in the summer, 2004. The water temperature range of the study area was $20.5{\sim}31.5^{\circ}C$ and there was formed a water temperature frontal zone from $20.5^{\circ}C$ to $25.0^{\circ}C$ in Geojedo southern coast and Geomundo island. Especially, high density of nutrients were shown in the southern coast of Geojedo in which water temperature frontal zone was formed strongly, the concentration of chlorophyll-a which is appeared at the highest rate among the phytoplankton pigments was shown more than $0.4{\mu}g/L$ in the inside of frontal zone and zooplankton biomass was than $500mg/m^2$ in that area.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.499-506
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• 2013

To estimate the effect of algae to particulate organic matter in the upper regions of brackish Lake Sihwa, temporal and spatial variations of particulate organic carbon (POC) and phytoplankton pigments (chlorophyll a; Chl-a, pheophytin-a; Pheo-a), and their relationships were studied at seven sites of the brackish regions from March to October 2005 and 2006. POC concentration varied from 1.0 to $76.6mgL^{-1}$ (mean $7.4mgL^{-1}$), with maximal concentrations occurring in the middle parts of the study area in spring of 2005 and 2006. Concentrations of Chl-a and Pheo-a varied from 1.3 to $942.9{\mu}gL^{-1}$ (mean $71.0{\mu}gL^{-1}$) and $1.4{\sim}1,545.5{\mu}gL^{-1}$ (mean $59.9{\mu}gL^{-1}$), respectively, and corresponded closely with variation in POC. During the study period Pheo-a concentration was 44.2% of total Chl-a, implying that non-living or inactive phytoplankton is also the important part of phytoplankton-derived POC in brackish regions of Lake Sihwa. From the positive linear relationships between POC and phytoplankton pigments (POC with Chl-a (r=0.93), total Chl-a (r=0.88), and Pheo-a (r=0.81)), it is suggested that phytoplankton was a significant component of POC in the upper regions of brackish Lake Sihwa. On the other hand, the ratios of POC/Chl-a and POC/total Chl-a (Chl-a+Pheo-a) were 82.9 and 35.9, respectively. The ratio of POC/total Chl-a is similar to those reported in previous studies, including 40~60 in estuaries. This study suggests that Pheo-a concentration is considered in estimation of POC concentration from phytoplankton pigments in aquatic systems with high content of Pheo-a, like an upper region of blackish Lake Sihwa.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1339-1348
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• 2020

Phytoplankton controls marine ecosystems in terms of nutrients, photosynthetic rate, carbon cycle, etc. and the degree of its influence on the marine environment depends on their physical size. Many studies have been attempted to identify marine phytoplankton size classes using the remote sensing techniques. One of successful approach was the three-component model which estimates the chlorophyll concentrations of three phytoplankton size classes (micro-phytoplankton; >20 ㎛, nano-; 2-20 ㎛ and pico-; <2 ㎛) as a function of total chlorophyll. Here, we examined the applicability of Geostationary Ocean Colour Imager (GOCI) to the mapping of the phytoplankton size class distribution in the East Sea. A fit of the three-component model to a biomarker pigment dataset collected in the study area for some years including a large harmful algal bloom period has been carried out to derive size-fractioned chlorophyll concentration (CHL). The tuned three-component model was applied to the hourly GOCI images to identify the fractions of each phytoplankton size class for the entire CHL. Then, we investigated the distribution of phytoplankton community in terms of the size structure in the East Sea during the harmful Cochlodinium polykrikoides blooms in the summer of 2013.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.1
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• pp.48-55
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• 2009

Seasonal variations of microalgal biomass and community composition in both the sediment and the seawater were investigated by HPLC pigment analysis in an estuarine muddy sandflat of Gwangyang Bay from January to November 2002. Based on the photosynthetic pigments, fucoxanthin, diadinoxanthin, and diatoxanthin were the most dominant pigments all the year round, indicating that diatoms were the predominant algal groups of both the sediment and the seawater in Gwangyang Bay. The other algal pigments except the diatom-marker pigments showed relatively low concentrations. Microphytobenthic chlorophyll ${\alpha}$ concentrations in the upper layer (0.5 cm) of sediments ranged from 3.44 (March at the middle site of the tidal flat) to 169 (July at the upper site) mg $m^{-2}$, with the annual mean concentrations of $68.4{\pm}45.5,\;21.3{\pm}14.3,\;22.9{\pm}15.6mg\;m^{-2}$ at the upper, middle, and lower tidal sites, respectively. Depth-integrated chlorophyll ${\alpha}$ concentrations in the overlying water column ranged from 1.66 (November) to 11.7 (July) mg $m^{-2}$, with an annual mean of $6.96{\pm}3.04mg\;m^{-2}$. Microphytobenthic biomasses were about 3${\sim}$10 times higher than depth-integrated phytoplankton biomass in the overlying water column. The physical characteristics of this shallow estuarine tidal flat, similarity in taxonomic composition of the phytoplankton and microphytobenthos, and similar seasonal patterns in their biomasses suggest that resuspended microphytobenthos are an important component of phytoplankton biomass in Gwangyang Bay. Therefore, considering the importance of microphytobenthos as possible food source for the estuarine benthic and pelagic consumers, a consistent monitoring work on the behavior of microphytobenthos is needed in the tidal flat ecosystems.