Seasonal dynamics of phytoplankton in the Nakdong River Estuary |
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학술지명 Korean Society of Limnology
저자 신재기
발표일 2021-12-09
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This study was monitored to analyze the distribution of phytoplankton in the freshwater zone of the Nakdong River estuary from July 2018 to October 2021. The quantitative surveys were performed simultaneously at three stations every month. A total of 144 species of phytoplankton were observed during this period. The variations in the species composition and cell density of phytoplankton were slightly seasonally different from year to year. However, the dominant population showed a relatively regular occurrence. In addition, the phytoplankton taxa that maintained high cell density in space and time were colony and filamentous. In general, Cyanophyceae were relatively dominant in the high-temperature summer, and Bacillariophyceae were dominant in other periods. These included the following phytoplankton: diatom Aulacoseira ambigua (maximum 6,910 cells/ml), Fragilaria crotonensis (11,350), Stephanodiscus hantzschii f. tenuis (26,000) and cyanobacteria Aphanizomenon flos-aquae (118,400), Microcystis aeruginosa (152,050), M. wesenberghii (27,500), Oscillatoria amphibia (134,600), O. tenuis (46,000), and Pseudoanabaena mucicola (16,500). In particular, the distribution of P. mucicola was closely related to that of M. aeruginosa. Finally, from comparison with past data, changes in species composition and cell density were detected in the distribution of dominant phytoplankton in the estuary after weirs entered the middle and lower reaches of the Nakdong River. |