• 해양환경안전학회지
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• 제28권4호
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• pp.459-468
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• 2022

천수만과 태안해역의 제한영양염을 평가하기 위해 장기자료 분석과 생물검정실험을 진행하였다. 우선 잠재적인 제한영양염을 평가하기 위해 국가수질측정망에서 제공되는 2004~2016년 동안의 장기 영양염 자료를 이용하였다. 장기자료의 DIN/DIP를 분석한 결과 대부분 16이하로 N 제한이 우세하였지만 N, P, Si의 농도비를 이용한 분석에서는 하계와 추계에는 N 제한이 우세하였고, 동계와 춘계에는 해역에 따라 일부 Si 제한을 보이거나 또는 제한이 나타나지 않았다. 생물검정실험 시 채집된 현장수의 영양염 분석결과, DIN/DIP는 3월과 5월에 모든 정점에서 P 제한을 나타냈고, 7월과 10월에는 N 제한이 우세하였다. N, P, Si의 농도비를 이용한 분석에서 3월과 5월은 P와 Si 제한을 보이거나 제한영양염이 나타나지 않은 정점이 존재하였으나 7월과 10월에는 N 제한이 우세하였다. 실질적인 제한영양염을 평가하기 위해 수행된 생물검정실험 결과 3월에는 특정 제한영양염이 나타나지 않았으나, 5월, 7월 10월에는 NH₄⁺와 NO₃^-가 반응을 보임으로서 이 시기에는 N이 식물플랑크톤 성장에 직접 관여하는 실질적인 제한영양염임을 확인하였다.

• 한국물환경학회지
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• 제23권4호
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• pp.512-517
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• 2007

The limiting nutrient of eutrophication in freshwater bodies in Korea was examined and the phosphorus concentration standard for sewage treatment effluent was discussed. The weight ratio of N/P in 13 major reservoirs showed the range of 18 to 163, which implies phosphorus is more limited than nitrogen for algal growth. In the correlation analysis phosphorus showed higher correlation with chlorophyll-a concentration than with nitrogen. In the algal bioassay phosphorus spike test enhanced algal growth in all 25 samples of five reservoirs, while nitrogen was found to co-limit only in four samples. It confirms that phosphorus is the only limiting nutrient for eutrophication in Korean reservoirs. As many reservoirs are eutrophic in Korea, phosphorus control is critical for the management of water quality. The phosphorus standard of sewage treatment effluent in Korea was compared with other countries, and it can be concluded that phosphorus standard is too high to be effective in eutrophication control and a lower phosphorus standard is essential for the water quality improvement.

• Ocean and Polar Research
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• 제29권4호
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• pp.349-366
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• 2007

Seasonal variations of various physicochemical components (temperature, salinity, pH, DO, COD, DOC, nutrients-silicate, DIN, DIP) and potential limiting factor for phytoplankton primary production were studied in the surface water of semi-enclosed Masan Bay. Seasonal variations of nutrient concentrations, with lower values in summer and winter, and higher in fall, are probably controlled by freshwater loadings to the bay, benthic flux and magnitude of occurrence of phytoplankton communities. Their spatial distributional patterns are primarily dependent on physical mixing process between freshwater and coastal seawater, which result in a decreasing spatial gradient from inner to outer part of the bay. In the fall season of strong wave action, the major part of nutrient inputs (silicate, ammonium, dissolved inorganic phosphorus) comes from regeneration (benthic flux) at sediment-water interface. During the summer period, high Si:DIN and Si:DIP and low DIN:DIP relative to Redfield ratios suggest a N- and secondarily P-deficiency. During other seasons, however, silicate is the potential limiting factor for primary production, although the Si-deficiency is less pronounced in the outer region of the bay. Indeed, phytoplankton communities in Masan Bay are largely affected by the seasonal variability of limiting nutrients. On the other hand, the severe depletion of DIN (relatively higher silicate level) during summer with high freshwater discharge probably can be explained by N-uptake of temporary nanoflagellate blooms, which responds rapidly to pulsed nutrient loading events. In Masan Bay, this rapid nutrient consumption is considerably important as it can modify the phytoplankton community structures.

• 한국환경과학회지
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• 제15권10호
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• pp.961-966
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• 2006

An algal assay procedure using an indigenous phytoplankton assemblage was tested to estimate the propagation of red tide phytoplankton species and determine the optimal time interval at which to measure growth yield in eutrophic marine waters where red tides frequently occur. Various red tide phytoplankton species were propagated on a large scale by adding nitrogen or phosphorous. This procedure was useful for estimating the limiting nutrient, elucidating the mechanisms underlying red tides, and determining the levels of increases in organic matter in eutrophic coastal waters. The algal assay using indigenous C. polykrikoides showed that this species did not always propagate, apparently because of very low concentrations of trigger elements that are necessary for its growth, rather than as a result of other environmental characteristics, e.g., water temperature or stress from sampling. In the winter, when water temperatures are lower than in spring, summer, or autumn, maximum propagation and the limiting nutrient could be estimated by measuring phytoplankton biomass at 2 - 3-day intervals. However, in the other seasons, when water temperatures are higher, phytoplankton biomass should be measured at 2-day intervals. In particular, daily monitoring will be required to determine precise growth yields in warm seasons.

• 한국토양비료학회지
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• 제37권5호
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• pp.329-335
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• 2004

Acid deposition in forest adjacent to the industrial complexes causes soil acidification resulting in the leaching of cations, decreases of buffering capacity and increases of toxic metal concentrations such as Al, Fe, Mn and Cu in soil solution. Changes of nutrient availability equilibria by acid deposition have been known to retard the growth of pine trees. Objective of this research was to assess the critical ratios of Ca/Al and Mg/Al limiting the growth of Pinus thunbergii in the hydroponic culture. The Ca concentration and Ca/Al ratio in stalks of pine tree were increased as increasing Ca/Al molar ratio in the nutrient solution, but were not changed when the Ca/Al molar ratio was adjusted to greater than 1. Growth of Pinus thunbergii was inhibited at the Ca/Al molar ratio lower than l due to the Ca deficiency. The molar ratios of Ca/Al in the needles of Pinus thunbergii showed the similar tendency with the stalks. This indicated that Ca/Al molar ratio of 1 in the growth media was the critical level limiting the growth of Pinus thunbergii. Concentration of Mg and Mg/Al molar ratios in the stalks of pine tree were increased as increasing Mg/Al molar ratio in nutrient solution. Molar ratios of Mg/Al in the needles were increased as increasing Mg/Al ratios in nutrient solution up to 0.83, which was the critical level limiting the growth of Pinus thunbergii.

• 환경생물
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• 제31권2호
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• pp.61-68
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• 2013

Microalgae can grow autotrophically with the supply of light, carbon dioxide and inorganic nutrients in water through photosynthesis. Generally, microalgal growth is limited by the concentrations and relative ratio of nitrogen (N) and phosphorus (P) among the nutrients in the aquatic environment. Each microalga has its specific optimum N : P ratio resulting in dominance in a particular water having similar nutrient composition. Algal bloom is an immense growth of certain microalga commonly cyanobacterium and can be sequestrated by reducing the limiting nutrient, generally P in the freshwater. Moreover, dominance of a less toxic blooming strain can be established by manipulating N : P ratio in the water. On the other hand, microalgal biomass of a certain species can be enhanced by increasing limiting nutrient and adjusting the N : P ratio to the target species. The above-mentioned eco-physiological features of microalgae can be more completely interpreted in connection with their genomic informations. Consequently, microalgal growth regulation which can be achieved on the basis of its eco-physiological and further genomic insights would be helpful not only in the control of algal bloom, but also for an increased yield of algal biomass.

• 한국물환경학회지
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• 제28권4호
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• pp.551-560
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• 2012

The objectives of this study were to elucidate spatio-temporal heterogeneity of water chemistry and develop empirical models using trophic variables in Daechung Reservoir during 2005-2010 along with in situ tests of nutrient enrichment bioassays (NEB). The relations of water quality parameters in regard to precipitation showed that seasonal and interannual fluctuations of biological oxygen demand (BOD), total nitrogen (TN) and pH were minor, whereas conductivity, suspended solids (SS), and total phosphorus (TP) were largely varied in response to the magnitude of rainfall. The CHL maxima occurred immediately after the spate of TP during the high flow, indicating that phytoplankton growth was directly controlled by phosphorus. Empirical linear models of CHL-TP indicated that the variation of CHL in premonsoon was accounted 60% ($R^2$ = 0.60, p < 0.05, n = 54) by TP. In the mean time, empirical models of annual CHL-TN showed that the variation of CHL was weakly accounted ($R^2$ = 0.16, p < 0.001) by TN and more strongly ($R^2$ = 0.44, p < 0.001) by TP. Thus, the variation of CHL was more explained by the variation of TP than TN. In situ tests of Nutrient Enrichment Bioassays (NEBs) showed that the growth of CHL was greater in the P-treatments (as $PO_4-P$) than the control and N-treatment (as $NO_3-P$). Overall, our results suggest that phosphorus was aprimary limiting nutrient controlling the seasonal phytoplankton growth, based on the in situ experiments of NEBs.

• 한국관개배수논문집
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• 제18권2호
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• pp.15-24
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• 2011

This study was carried out to analyze characteristics of water quality and correlation among water quality parameters in Idong reservoir used for agricultural water. The pH and concentrations of DO, SS, BOD, COD, TP, Chl-a in Idong reservoir almost met the water quality standards for agricultural water, but TN concentration exceeded the water quality standards for agricultural water. All of water quality items had no significant difference between horizontal points at 95% confidence level and the Idong reservoir was possible to be treated as the single water body. As NIP ratio of the Idong reservoir is 52, TP is a limiting nutrient salt. As TN exceeds the water quality standards, it is required to preserve TP below current state to prevent water bloom by eutrophication. Therefore, reduction of phosphorus from the watershed is necessary for controlling the eutrophication of Idong reservoir.

• 해양환경안전학회지
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• 제23권7호
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• pp.885-892
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• 2017

2017년 추계에 남해 전선역을 파악하고, 알칼리 인산분해 효소(Alkaline Phosphatase; APase) 활성을 이용하여 제한 영양염과 제한 영양염의 시간적인 변화를 평가하였다. 전선역이 형성된 인근해역의 경우, 용존무기인(dissolved inorganic phosphorus; DIP)의 농도와 용존무기질소(dissolved inorganic nitrogen; DIN): DIP 비가 각각 $0.2{\mu}M$ 이하와 최대 23.2로, DIP가 제한된 환경임에도 불구하고 Chlorophyll a(Chl.-a)가 $0.2{\mu}g/L$로 높은 생물생산력을 보였다. APase와 DIP는 중요한 역의 상관관계(r = -0.81; P<0.001)를 보여, DIP가 제한되어진 해역임을 알 수 있었으며, APase와 Chl-a 관계는 APase의 60 %가 식물플랑크톤, 40 %가 박테리아 기원인 것으로 평가되었다. 용존태 APase와 입자태 APase의 분포로부터 전선역은 장기간 DIP가 제한된 해역이며, 그 외의 해역은 최근에 DIP 제한이 해소된 것으로 판단되었다. 따라서 전선역에서 APase와 같이 가수분해효소의 측정은 제한 영양염의 시공간적인 변화 특성을 평가할 수 있으며, 전선역에서 생지화학 순환의 이해를 높일 수 있을 것으로 생각된다.

• ALGAE
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• 제21권2호
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• pp.229-234
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• 2006

For the test organism of algal growth potential (AGP), the diatom in the genus Stephanodiscus which cause blooms in the Nakdong River was used instead of generally used strains of Selenastrum, Microcystis, or Anabaena. AGP results indicated that all the samples in the Nakdong River except for that from the Nakdan Bridge site were eutrophic state. Furthermore, the sample from Kumho River site was hypertrophic state. In the main stream Nakdong River, the value of AGP was lowest at the upstream Nakdan Bridge site and was highest at Koryoung Bridge site which is just downstream of Kumho River confluent point indicating the seriousness of pollution contributed by the Kumho River to the Nakdong River. Changes in the concentration of nutrients before and after the AGP tests and inter-relationship among the nutrients indicated that the growth of the Stephanodiscus in the AGP tests were mostly affected by the nitrate, silicate and phosphate. The limiting nutrient was identified by the nutrient addition experiments and the results showed that phosphate was the limiting nutrient for the growth of Stephanodiscus in the tested samples.