• Journal of Marine Bioscience and Biotechnology
• /
• v.5 no.4
• /
• pp.46-50
• /
• 2011

Phytoplankton forms the base of sea ecosystems. Various environmental factors and anthropogenic pollution, primarily, affect the concentration and photosynthetic activity algal cells, and the changes in the phytoplankton photosynthesis influence other elements of aquatic ecosystems. The increase in anthropogenic pollution markedly damages natural aquatic ecosystems, particularly, in the coastal zones, where an intense blooming of microalgae occurs, including the release of highly dangerous ecotoxic substances of various chemical natures (red tides). In this study, we tried to apply as a parameter for the algal blooming prediction in the ocean from fluorescence values in the taken samples around Busan coastal area. F0 value was almost constant but Fv/Fm value showed the irregular pattern. We presume that these results are due to the changes of the ocean environment and climate. To predict or give early warning the algal blooming, we need to investigate the specific area or fixed area through real-time monitoring. Especially, algal blooming prediction or warning can be achieved via continuously monitoring and interpretation of fluorescence changes.

• The Korean Journal of Ecology
• /
• v.20 no.1
• /
• pp.61-68
• /
• 1997

Due to its lack of wave action and tide ecosystem in Inchon dock lacks in marine characteristics. Structural condition in the dock is artificially similar to that of lake. The purposes of this study was to clarify the water quality, to provide the basic physicochemical data and tl resolve the causation of ？미 blooming. Samples were obtained monthly from four stations in Inchon dock during January to December, 1991. Water temperature ranged from $2.7^{\circ}C$ to $27.6^{\circ}C$ under the strong influence of air temperature. Salinity varied between 24.7%-30.4% thus being influenced by freshwater discharged from a spring. Dissolved oxygen was concentrated from 0.1-13.92 mg/l and suspended solids were 6.9-231.0 mg/l. The physicochemical factors were similar to those investigated 10 years ago. However, increased concentration of nitrogenous nutrients initiated ？미 blooming and its process was accelerated to reach eutrophication. Algal blooming was proceeded in March and August.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.21 no.3
• /
• pp.93-98
• /
• 2013

Main causes of algal bloom was studied in Paldang reservoir. Statistical approach was tried using meteorological and water quality data. Algae alert system showed that more than ten days were counted in a year, once it happened in Paldang reservoir. Alert dates increased in recent 5 years. Correlation coefficients between chlorophyll-a and other indexes did not showed strong relations resulting in coefficients less than 0.4. Among them, sunshine duration, BOD, and flow rate were appeared relatively main causes of algal blooming. Sunshine duration and BOD showed positive relation while flow rate did negative one, which is resonable for photosynthetic microorganisms. Water temperature and total phosphorus, which were presumed probable main causes before study, resulted in low correlation coefficients. Correlation coefficients between discharge flow and rainfall, water temperature showed positive relation due to seasonal effect.

• ALGAE
• /
• v.18 no.4
• /
• pp.361-363
• /
• 2003

This study was conducted at Seomjin River estuary to identify the causative species of algal bloom and their blooming cycles. Field surveys were conducted at 4 stations in every week from April to December of 1999. Thirty species were observed as the causative species of alga bloom. Skeletonema costatum, Thalassiosira sp., and microflagellate spp. (mixed red tide: Chroomonas sp. and two species of Prasinophycea) made algal blooms during the present study period. In addition, toxic algal species of diatom Pseudo-nitzschia multiseries and dinoflagellate Dinophysis acuminata were observed. The algal blooms were caused by microflagellate spp. in June, Thalassiosira sp. in July and Skeletonema costatum in August. Generally, the algal blooms persisted for about 5 days in this area.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.08a
• /
• pp.82.6-83
• /
• 2008

• Journal of Environmental Science International
• /
• v.25 no.7
• /
• pp.937-950
• /
• 2016

Algal blooming in 4 major rivers introduces substantial impacts to water front activity. Concentrations of algae are increasing at major points along the Geum River. Ecosystem food webs can be affected by algal blooming because blue-green algae release toxic materials. Even though there have been many studies on blue-green algae, its causality to environmental factors has not been completely determined yet. This study analyzed the exclusive correlation between various hydrometeorological, water quality, and hydrologic variables and the cell number of cyanobacteria to understand causality of blue-green algae in the Geum River. A prewhitening process was introduced to remove the autocorrelation structure and periodicity, which is useful to evaluate the effective relationship between two time series.

• Journal of Korean Society on Water Environment
• /
• v.31 no.5
• /
• pp.533-542
• /
• 2015

In order to investigate the effect of internal loading from sediment on algal blooming at Chusori area in Daechung Reservoir, the amount and contamination level of sediment and the release rate of total phosphorus were analyzed. The sedimentary layer was consisted with two layers, and the average depth of upper and lower ones were 0.35 and 1.44 m, respectively. The fraction of inorganic phosphorus in the sediment was higher than that of organic phosphorus, and the fractions of phosphorus which responsible for internal loading were very high as in the range of 72.7 and 80.2% of inorganic phosphorus. The C/N ratio of sediment taken with core sampler indicated the organic compounds are originated from settled algae from water body. The average release rate of total phosphorus from sediment was $6.74({\pm}0.50)mg/m^2/day$. These results indicated that the internal loading from sediment contributes the excessive algal growth at Churosi area, and the countermeasures to improve the quality of sediments are required to manage algal blooming in Daechung Reservoir.

• Proceedings of the KSRS Conference
• /
• v.2
• /
• pp.529-532
• /
• 2006

The oceanic currents in the South China Sea (SCS) are strongly influenced by monsoon winds. A review on the SCS currents has indicated that previous studies have pointed out an anticyclonic circulation in the area between the southern Vietnam coast and the Spratly Islands. However, its detail is not understood because of less information of in situ observations. The physical-biological interaction is quite new research area, which has been established and promoted by means of the ocean color remote sensing. Temporal/spatial variability of the phytoplankton activities are well captured by ocean color (OC) -derived Chlorophyll-a images. Combining the OC-Chl-a and the other high-resolution satellite data (e.g., SST images), the biological aspects of oceanographic variation is well described. The blooming phenomena in the area between the southern Vietnam coast and the Spratly islands are further investigated. Change in the wind-system related to the El Nino generates upwelling/SST-cooling in the sea south of the Spratly Islands through the air-sea-land interaction was studied. The seasonal upwelling is also associated with the harmful algal bloom (HAB) off two side of Indochina Peninsula have investigated. The seasonal variation of SCS phytoplankton blooming and related oceanic conditions in Vietnam coast was observed. Ocean color satellite data has effective contribute to study the oceanic condition and phytoplankton blooming in South China Sea.

• The Korean Journal of Ecology
• /
• v.11 no.1
• /
• pp.1-15
• /
• 1988

Studies on species compostion, promary production of benthic algal assemblage were carried out along a channel of the salt marsh near Inch'on, Kyonggi Bay, Korea. Possible biological, physical and KDICical factors controlling the aglal assemblage were also examined. The oveall diatoms were encountered one hundred and thirty-seven taxa, of which the dominant species were Paralia sulcata and Cymatosira belgica. These two species accounted for 32.6% relative abundance throughout the study period. Diatom taxa had no clear seasonal pattern in abundance analysis. But at the algal blooming period in spring, euglenoids occurred with a high abundance. The chlorophyll a content of benthic algae showed definite seasonal pattern. The algal biomass of the appeared to influence the spatial fluctuation in the algal biomass of the channel was regulated primarily by water content of sediment. Grazing by zoobenthos apperaed to influence the spatial fluctuation in the algal biomass of the sediment surface. The algal photosynthesis was measured in the laboratory with oxygen method. Photo-synthetic rate was independent of the temperature under the lower irradiance. The gross production from March to November was estimated to be 190g C/m2 at the channel slope. Photosynthetic efficiency was 0.37% on the basis of the photosyntherically active radiation for the study period.

• Korean Journal of Ecology and Environment
• /
• v.34 no.4 s.96
• /
• pp.292-297
• /
• 2001

As a part of study on the microalgal dynamics in a small pond in Hongsung, Chungnam, we found a massive bloom of chlorococcalean green alga, Dictyosphaerium pulchellum during the year-round survey from January 2000 to January 2001. D. pulchellum occurred at a low frequency throughout the year. However, D. pulchellum began to increase from 12 March, showed a peak of blooming with 59,200 colonies $mL^{-1}$ in 2 April, and abruptly decreased in 16 April. Colonies were 8-celled and 16-celled at early stage of blooming, 32-celled or 64-celled at the midst of blooming, and most of colonies consisted of 64 cells at the end of blooming. Colonies of D. pulchellum were healthy at the early stage of blooming, but most of colonies were infected with some parasites at the end of blooming. The infected cells bleached out with decomposing chloroplast and pyrenoids. The infection with parasites, together with irradiance and nutrient limitations, appears to stop D. pulchllum bloom. This is the first report on the occurrence of blooming of a green algal genus Dictyosphaerium and its infection with parasite in Korea.