Environmental Studies of the Lower Part of the Han River V. Blooming Characteristics of Phytoplankton Communities

doi:2003.18.4.255

Algae > Volume 18(4); 2003 > Article

Algae 2003;18(4): 255-262. doi: https://doi.org/10.4490/ALGAE.2003.18.4.255

Seung Won Jung, Jin Hwan Lee, Jong Su Yoo

Division of Natural Science, Sangmyung University, Research Institute of Marine Science and Technology, Korea Maritime University

ABSTRACT

Ecological characteristics of phytoplankton communities were investigated biweekly at 6 stations from Feb. 2001 to Feb. 2002 at the lower part of the Han River. During the study, a total of 267 taxa which were composed of 114 green algae, 104diatoms, 22 blue-green algae, 13 chrysophytes and 2 dinoflagellates were observed. The standing crops of phytoplankton communitites were ranged from 1.30×106 cells/L to 37.47×106 cells/L. The dominant species were 11 taxa including Pediastrum duplex, Scenedesmus quadricauda in green algae, Osillatoria limosa, Microcystis aeruginosa, Merisomorpedia sp., Phormidium sp. in blue-green algae, and Asterionella gracillima, Aulacoseira granulata, Fragilaria crotonensis, Stephanodiscus hantzschii f. tenuis, Synedra acus in diatoms. Asterionella gracillima and Stephanodiscus hantzschii f. tenuis were abundant at every station from winter to spring. Stephanodiscus hantzschii f. tenuis occupied the highest dominant ratio and standing crop. From summer to autumn, dominant species were Aulacoseira granulata at all stations and blue-green algae such as Osillatoria limosa, Microcystis aeruginosa, Merisomorpedia sp. at some stations. These 4 species were mostly present at the lower stations 4, 5, 6 and very few at the upper stations 1, 2, 3.

Key words: blooms, dominant species, Han River, phytoplankton communities, standing crops