• 생태와환경
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• 제35권3호통권99호
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• pp.187-197
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• 2002

아산호에서 1997년 3월부터 1997년 11월까지 6회에 걸쳐 식물플랑크톤 군집구조를 파악하기 위한 연구를 수행하였다. 19개 정점에서 관찰된 식물플랑크톤 분류군은 총 204종군으로, 각 분류군별 출현비는 녹조류 51%, 규조류 29%, cyanobacteria 12%, 와편모조류가 2%, 유글레나류 4%, 기타 편모조류가 2% 이었다. 식물플랑크톤의 현존량은 741ce11s/m떼서 613,066ce11s/ml의 범위로 매우 높은 수준으로 나타났다. 현존량은 7월에 가장 높았고 9월, 6월, 3월, 11월, 5월 순으로 나타났다. 계절에 관계없이 지속적으로 녹조상태인 것으로 판단되며, 녹조원인생물은 Micractium pusillum, Stephandiscus hantzschii, Dictyospharium pulchellum, cryptomonad (> 20 ${\mu}$, Microcystis aeruginosa, Oscillatoria tenuis, Oscillatoria sp., Aphanocapsa sp. Euglena sp., Volvox aureus 이었다. 여름철에 cyanobacteria에 의한 녹조현상이 현저하였다. 식물플랑크톤의 종다양성은 0.13${\sim}$의 범위로 시${\cdot}$공간적으로 차이가 매우 컸다. 집괴 분석한 결과 전반적으로 아산호 하류수역과 상류수역 투 개의 수역으로 구분이 되었다.

• Fisheries and Aquatic Sciences
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• 제7권3호
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• pp.122-129
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• 2004

Harmful Cochlodinium polykrikoides is a notorious harmful algal bloom (HAB) species that is causing mass mortality of farmed fish along the Korean coast with increasing frequency. We analyzed the sequence of the large subunit (LSD) rDNA D1-D3 region of C. polykrikoides and conducted phylogenetic analyses using Bayesian inference of phylogeny and the maximum likelihood method. The molecular phylogeny showed that C. polykrikoides had the genetic relationship to Amphidinium and Gymnodinium species supported only by the relatively high posterior probabilities of Bayesian inference. Based on the LSU rDNA sequence data of diverse dinoflagellate taxa, we designed the C. polykrikoides-specific PCR primer set, CPOLY01 and CPOLY02 and developed PCR detection assays for its sensitive, accurate HAB monitoring. CPOLY01 and CPOLY02 specifically amplified C. polykrikoides and did not cross-react with any dinoflagellates tested in this study or environmental water samples. The effective annealing temperature $(T_{p})$ of CPOLY01 and CPOLY02 was $67^{\circ}C$. At this temperature, the conventional and nested PCR assays were sensitive over a wide range of C. polykrikoides cell numbers with detection limits of 0.05 and 0.0001 cells/reaction, respectively.

• 환경위생공학
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• 제13권2호
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• pp.1-13
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• 1998

Seasonal variation of algae distribution were studied in the Chuam reservoir from August 1996 to July 1997. As a result, 127 taxa were observed, representing 6 classes, 14 orders, 5 suborders, 29 families, 2 subfamilies, 54 genus, 118 species, 7 variaties and 2 formula. The majors of them are Chlorophyceae (59 taxa), Bacillariophyceae(39 taxa) and Cyanophyceae(20 taxa). The number of species was that 35 and 31 taxa were occurred in August 1996 and April 1997, 11 and 17 taxa in July 1997 and October 1996 respectively at Dam station, 53 taxa were occurred in September, 18 taxa in November at Munduck station. The biomass composition of occurrence species were as fallowes; Cyanophyceae are 80%, Bacillariophyceae 14% and Chlorophyceae 5% at Dam station and Cyanophyceae are 90%, Bacillariophyceae 1.3% and Chlorophyceae 0.4% at Munduck at Munduk station. At Munduk station, water bloom occurred by Cyanophyceae(99.9%, 3.7 $\times$ 10$^{7}$ cells/L) in November 1996 and the major causing algae was Microcrystis aeruginosa. Microcystis aeruginosa was dominant species (dominant index : 0.72 - 0.99) during summer and autumn, Fragilaria crotonensis and Asterionella formasa (DI : 0.33 - 0.74) during winter and spring. The water quality factors of the Chuam reservoir were that the values of water temperature ranged of 3.6 - 31.4$\circ$C, pH 6.7 - 9.0, conductivity 69.6-118.2 $\mu $s/cm, and turbidity 1.0-22.5 NTU, and the proper temperature of water for algae growth was 15 and 16.7$\circ $C in April and November. Also the concentration of dissolved oxygen(DO) ranged of 6.8-15.5mg/L, total nitrogen(T-N) 0.54-1.78 mg/L, total phosphrous (T-P) 0.003-0.034 mg/L, and chlorophyll-a 0.9-23.2mg/m$^{3}$. The concentration of Chlorophyll-a was in inverse proportion T-N/T-P ratio.

• 한국물환경학회지
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• 제34권4호
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• pp.375-381
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• 2018

The monitoring of phytoplankton biomass and community structure is essential as a first step to control the harmful cyanobacterial blooms in freshwater systems, such as seen in rivers and lakes, due to the process of eutrophication and climate change. In order to quantify the biomass of phytoplankton with a wide range in size and shape, the measurement of cell biovolume along with cell density is required for a comprehensive review on this issue. However, most routine monitoring programs preserve the gathered phytoplankton samples before analysis using chemical additives, because of the constraint of time and the number of samples. The purpose of this study was to investigate the cell biovolume change characteristics of six cyanobacterial species, which are common bloom-causing cyanobacteria in the Nakdong River, after the preservation with Lugol's iodine solution. All species showed a statistically significant difference after the addition of Lugol's iodine solution compared to the live cell biovolume, and the cell biovolume decreased to the level of 34.0 ~ 56.3 % at maximum in each species after the preservation. The nonlinear regression models for determining the shrinkage ratio by a preservation period were derived by using the cell biovolume measured until 180 days preservation of each target species, and the equation to convert the cell biovolume measured after preservation for a certain period to the cell biovolume of viable cell was derived using that formula. The conversion equation derived from this study can be used to estimate the actual cell biovolume in the natural environment at the time of sampling, by using the measured biovolume after the preservation in the phytoplankton monitoring. Moreover this is expected to contribute to the final interpretation of the water quality and aquatic ecosystem impacts due to the cyanobacterial blooms.