• 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.

• 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.

• 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.

• 한국환경과학회지
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• 제4권5호
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• pp.469-479
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• 1995

The increase of population and industrial activities had brought into eutrophication in the Nakdong river. A remarkable acceleration of eutrophication brought about serious problems for water supply. Therefore, for the purpose of conservation of water quality in the Nakdong river it is necessary to control nutrients. MBOD method was use to evaluate algal growth limiting factor and algal growth potential in the Nakdong river from June to August 1994. The modified biochemical oxygen demand(MBOD) depends on the amount of available inorganic nutrient and organic substrate during 5 day incubation in the dark at 2$0^{\circ}C$. The MBOD assay depends on inorganic nutrients such as P and N as well as reduced carbon and called the MBOD, the MBOD-P, and the MBOD-N, respectively. The results of bioassay by MBOD(Modified BOD) method showed that the MBOD, MBOD-P and MBOD-N value were found to be in the ranges of 3.8~96.0 mg$O_2$/l, 5.6~94.0 mg$O_2$/l and 42.0~220 mg$O_2$/l, respectively. And the the bioassay value was found to be the highest in Koryong area and the lowest in Waekwan area throughout the Nakdong river. The variations of MBOD-P and MBOD-N value showed similar tendencies to the variations of phosphorus and nitrogen value, respectively. By MBOD method, the relationships of MBOD, MBOD-P and MBOD-N value were MBOD ≒ MBOD-P 《 MBOD-N. The MBOD value was nearly equal to the MBOD-P value, and the MBOD-N value was 3 to 20 times more than the MBOD-P value, approximately. Therefore, in the Nakdong river, phosphorus was the limiting factor for algal growth during summer season. The algal growth potential as the concentration of chlorophyll-a in the summer was maximum 5 times more than standing crop as it.

• Environmental Engineering Research
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• 제14권4호
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• pp.220-225
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• 2009

The water quality in eutrophic lakes is affected by serious problems, such as abnormal increasing of Cyanobacteria. The purpose of this study was to investigate the possibility of a modified flotation system using a hybrid technique formed by chemical compounds and an electrostatic bridge. Therefore, experiments using the hybrid technique were performed to measure the zeta potential value on the phytoplankton surface and the removal efficiencies of phytoplankton, ammonia nitrogen, nitrate nitrogen and phosphoric acid. The results were as follows: Firstly, the zeta potential of M.aeruginosa was observed to approach charge neutralization due to adhesion of magnesium hydroxide precipitate on the phytoplankton surface in the pH range 10.5 to 11. Secondly, the concentration of chlorophyll-a decreased from about 150 to 20${\mu}g$g/L, with a maximum removal efficiency of 84% due to coagulation with pH values higher than 10. Thirdly, the N$H_4$-N concentration was observed to decrease from 0.62 to 0.54mg-N/L (13%), and the P$O_4$-P concentration, which is a limiting factor to the formation of algae blooms, decreased from 0.27 to 0.02mg-P/L (92%). These findings suggest that the modified flotation system can be applied for the purification of the raw water of numerous lakes containing high phytoplankton populations and elevated pH.

• 생태와환경
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• 제36권2호통권103호
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• pp.139-149
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• 2003

팔당호 식물플랑크톤의 제한영양염과 생리학적 성장 특성을 평가하기 위하여 2002년 3월부터 10일까지 팔당호의 수질환경 조사와 함께 실내 배양실험을 실시하였다. 총인의 농도와 Chl. a의 상관성 분석결과, 팔당호의 호수생산성은 인의 영향을 많이 받으며 TN/TP ratio와 식물플랑크톤의 성장잠재력 실험을 통해서도 제한영양염은 인으로 평가되었다. 특히, 봄철이 다른 계절에 비해 상대적으로 용존무기인이 낮은 농도로 존재하기 때문에 높은 인 제한을 받는 것으로 나타났다. 그러나 인의 제한정도는 계절적인 변이를 나타내었으며, 시기에 따라 질소와 규소에 의한 제한가능성도 나타났다. 팔당호 식물플랑크톤 군집의 최대성장률(${\mu}_{max}$)은 0.8${\sim}$l.1$day^1$의 범위로 나타났으며, 반포화농도($K_u$)는 0.1${\sim}$O.8${\mu}M$로 5월에 $0.8{\mu}M$로 가장 높고 9월에 $0.1{\mu}M$로 가장 낮은 것으로 조사되었다. 이는 영양염 흡수에 영향을 미치는 인의 cell quota와 관련이 있는 것으로 나타났으며, 5월에 $0.13{\mu}gP/{\mu}gChl.$ 3로 낮은 값을 나타냈다. 식물플랑크톤의 성장특성 분석을 통해 팔당호에서는 봄에 비해 여름과 가을철에 발생한 식물플랑크톤의 성장이 경쟁적으로 빠르게 발달할 수 있는 잠재성이 있는 것으로 판단된다. 결과적으로, 팔당호 식물플랑크톤 성장은 주로 인에 의하여 제한되며 여름 몬순 이후 수체의 안정기동안 높은 성장을 할 수 있는 생리적 특성을 가지고 있는 것으로 추정된다.

• 생태와환경
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• 제36권2호통권103호
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• pp.161-171
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• 2003

본 연구는 도심에 위치한 얕은 인공호수의 수질변화 특성, 제한영양염 및 퇴적물 특성을 평가하기 위해서 이루어졌다. 일감호는 연 평균 엽록소 a($77.2{\pm}36.6\;{\mu}g/l)와 TP ($66.6{\pm}20.5\;{\mu}g/l)농도 그리고 영양상태지수 (>60)모두를 토대로 할 때 매우 부영양상태였다. 결빙시기와 해빙되는 시기에 수층내 무기질소와 인의 수체내 농도가 증가하였다가 여름철에는 감소하는 계절적인 변화가 나타났다. 수체내 DIN/DIP(무게비)비율과 TSI편차분석 그리고 생물검정 (AGP)실험을 통해서 질소와 인 모두가 식물플랑크톤의 성장을 제한함이 제시되었다. TSI편차분석 결과에서는 1년 중 생물검정을 통해서도 인 제한이 예측된 바 있는 9월부터 11월에 인과 질소 모두의 식물플랑크톤 성장에 대한 제한정도가 가장 큰 것으로 나타났다. 퇴적물내 인 함량(313${\pm}$155mgP/kg)은 계절에 따른 변화를 나타났고, 인용출률은 pH9에서 0.29${\pm}$0.02Pmg $m^{-2}$ $day^{-1}$로 가장 높았다. 질소함량은 평균 4,452${\pm}$283.0 mg N/kg였으며 계절에 따른 큰 차이는 없었다. 이러한 결과들은 퇴적물이 제한영양염의 공급원으로서의 중요한 역할을 수행하며, 퇴적물내 인 함량의 계절에 따른 변화가 조류의 생물량을 조절할 수 있음을 의미한다.

• Journal of the korean society of oceanography
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• 제38권4호
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• pp.185-210
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• 2003

This paper describes and assesses the parameterisation of MP, the microplankton compartment of the carbon­nitrogen microplankton­detritus model. The compartment is 'the microbial loop in a box' and includes pelagic bacteria and protozoa as well as phytoplankton. The paper presents equations and parameter values for the autotroph and microheterotroph components of the microplankton. Equations and parameter values for the microplankton as a whole are derived on the assumption of a constant 'heterotroph fraction'. The autotroph equations of MP allow variation in the ratios of nutrient elements to carbon, and are largely those of the 'cell­quota, threshold­limitation' algal growth model, which can deal with potential control of growth by several nutrients and light. The heterotroph equations, in contrast, assume a constant elemental composition. Nitrogen is used as the limiting nutrient in most of the model description, and is special in that MP links chlorophyll concentration to the autotroph nitrogen quota.

• Ocean and Polar Research
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• 제33권2호
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• pp.99-111
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• 2011

To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semien-closed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.

• 한국해양학회지:바다
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• 제16권1호
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• pp.27-38
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• 2011

동계 진해만 광역해역의 식물플랑크톤의 군집구조와 영양염 제한 특성을 파악하고자 식물플랑크톤 군집의 정점간 비교와 환경인자간의 관계를 조사하였다. 아울러 식물플랑크톤의 성장에 영향을 미치는 제한영양염을 평가하기 위해서 현장수를 이용하여 생물검정실험을 수행하였다. 조사기간동안 규조류와 은편모조류는 대부분의 정점에서 전체 식물플랑크톤의 90% 이상을 점유하였고, 식물플랑크톤의 현존량은 마산만이 진해만 보다 현저히 높게 관찰되었다. DIN:DIP 비, pH, 투명도는 식물플랑크톤의 생물량과 유의한 양(+)의 관계를 보였다. 식물플랑크톤 군집구조를 바탕으로 Cluster 분석과 MSD 분석을 한 결과 크게 3개의 그룹으로 구분되었다. 제 1그룹은 고성과 통영을 중심으로 한 진해만 서부해역으로 은편모조류가 전체 식물플랑크톤 현존량에 50% 이상으로 우점하였다. 제 2그룹은 마산만 가장 내측해역으로 높은 생물량, 낮은 투명도, 높은 DIN:DIP 비가 관찰된 것이 특이적이였다. 제 3그룹은 진해만 동부수역에 해당되는 마산만 외측과 진해만 중앙해역으로 구분이 되었고, 이들 정점의 특성은 DSi:DIP 비가 높았고, 규조류가 우점출현하였다. 영양염 절대농도와 구성성분비에 의한 제한영양염과 생물검정실험을 통한 영양염 제한은 마산만 대부분의 정점은 P 영양염의 제한이 관찰되었고, 진해만은 N기원의 영양염제한이 식물플랑크톤의 증식에 중요한 역할을 하는 것으로 파악되었다. 동계 진해만은 규산염이 상대적으로 풍부하게 존재하였고, 이는 규조류가 우점하기 좋은 환경이라 사료된다.