Myeong-Seop Byeon

Probabilistic prediction of cyanobacteria abundance in a Korean reservoir using a Bayesian Poisson model

There have been increasing reports of harmful algal blooms (HABs) worldwide. However, the factors that influence cyanobacteria dominance and HAB formation can be site-specific and idiosyncratic, making prediction challenging. The drivers of cyanobacteria blooms in Lake Paldang, South Korea, the summer climate of which is strongly affected by the East Asian monsoon, may differ from those in well-studied North American lakes. Using the observational data sampled during the growing season in 2007–2011, a Bayesian hurdle Poisson model was developed to predict cyanobacteria abundance in the lake. The model allowed cyanobacteria absence (zero count) and nonzero cyanobacteria counts to be modeled as functions of different environmental factors. The model predictions demonstrated that the principal factor that determines the success of cyanobacteria was temperature. Combined with high temperature, increased residence time indicated by low outflow rates appeared to increase the probability of cyanobacteria occurrence. A stable water column, represented by low suspended solids, and high temperature were the requirements for high abundance of cyanobacteria. Our model results had management implications; the model can be used to forecast cyanobacteria watch or alert levels probabilistically and develop mitigation strategies of cyanobacteria blooms.

Molecular Identification of the Bloom-forming Cyanobacterium Anabaena from North Han River System in Summer 2012.

Molecular Identification of the Bloom-forming Cyanobacterium Anabaena from North Han River System in Summer 2012. LI, Zhun, Myung-Soo Han, Su-Ok Hwang, Myeong-Seop Byeon, Soon-Jin Hwang and Baik-Ho Kim* (Department of Life Science, Hanyang University, Seoul 133-791, Korea; K-waters, Korea Water Resources Corporation, Gwacheon, Gyeonggi 427-100, Korea; Han River Environment Research Center, National Institute of Environmental Research, Gyeonggi 427-100, Korea; Department of Environmental Science, Konkuk University, Seoul 143-701, Korea)

Water quality improvement through the interaction of biotic and abiotic variables within the rhizospheric zone of an artificial floating vegetation island

ABSTRACT Demands for water quality improvement and reduction of harmful algal blooms in Korean lakes and rivers due to eutrophication and climate change have been increasing. As an environmentally friendly measure to mitigate the eutrophication and phytoplankton growth, a full-scale artificial floating vegetation island (AFVI) was installed in Lake Paldang, a large on-river reservoir. This study investigated the detailed mechanisms for improving water quality and reducing the phytoplankton growth of the AFVI by comparing the biotic and abiotic environmental factors between the AFVI and the adjacent pelagic part of the lake. Much lower chlorophyll a concentration, much higher zooplankton biomass, especially large crustacean zooplankton, and a higher proportion of active bacteria in total bacteria in the AFVI indicate an effective reduction of phytoplankton growth and vigorous decomposition of organic matter. The major mechanisms for improving water quality of the AFVI are shown to be inhibition of phytoplankton growth by attenuating light and top-down control by zooplankton grazing. Active microbial decomposition of organic matters and nitrate reduction in the hypoxic rhizospheric zone also would be a major mechanism for improving water quality, even though it is difficult to quantify in the open water system.

Relationship between a Dense Bloom of Cyanobacterium Anabaena spp. and Rainfalls in the North Han River System of South Korea.

2012년 5월부터 2013년 4월까지 북한강 수계 3개의 연속댐(의암호, 청평호, 팔당호)의 수리-수문, 수질 및 식물플랑크톤 현존량 등을 월 1회씩 총 12회에 걸쳐 조사하였다. 3개 저수지의 식물플랑크톤 군집은 몬순전기에는 돌말류, 몬순기에는 남조류, 몬순후기에는 다시 돌말류가 우점하는 계절성을 보였으며, 팔당호에서는 몬순후기 저온기에 녹조류가 높은 밀도를 나타냈다. 조사기간동안 가장 높은 현존량을 보였던 남조 Anabaena spp.는 의암호에서 2012년 6월에 출현하여 7월에 최고치(43,850 cells

Sources and spatial and temporal characteristics of organic carbon in two large reservoirs with contrasting hydrologic characteristics

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Relationships between land use and multi-dimensional characteristics of streams and rivers at two different scales

)를 보이고 높은 수준을 유지하다가 11월에 소멸되었다. 이에 비해 청평호 (31,648 cells

Distribution patterns of fish communities with respect to environmental gradients in Korean streams

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Length-weight relationships of 19 freshwater fishes from the Daechung Reservoir in South Korea

)와 팔당호 (7,136 cells

Current Status and Perspectives in the Akinete Study of the Blue-green Algal Genus Anabaena.

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Length–weight relationships of eight cyprinid fishes from the Geum River in South Korea

)에서는 공히 7월에 처음 출현하여 8월에 최고치를 보이다가 9월에 완전히 사라졌다. 수환경과 남조 Anabaena spp. 현존량과의 관계를 보면, 3개 저수지 모두 강우 (r=0.72, r=0.83, r=0.88, P 【To evaluate the relationship between dynamics of Cyanobacterial bloom and rainfalls, a monthly monitoring of water quality and phytoplankton from the three serial lakes (Lake Ui-am, Lake Chung-pyeong and Lake Pal-dang) in the North Han River System were examined 12 times from May 2012 to March 2013. A dense bloom of cyanobacterium Anabaena spp., was occurred over three lakes in the summer season of 2012. In Lake Ui-am, the Anabaena population appeared in June, showed a peak in July (43,850 cells