Algae. 1996; 11(3): 277-283.

A Study on the Phytoplankton in the Paldang Dam Reservoir III. The Changes of Diatom Community Structure

Kyung Lee, Sook-Kyung Yoon

Department of Biology, The Catholic University of Korea

The seasonal changes of diatom community structure was investigated at four stations in the Paldang Dam Reservoir from April, 1994 to October, 1995 at bimonthly interval. Total number of diatom species identified were 87 spp. Compared with other previous studies, the total number of diatom species occurred has decreased gradually. There was a bimodal pattern showing maximum of diatom standing crops on June and December at the all investigated stations except for the station 2 in October 1995, and the continuous increase of diatom standing crops size, and the change of diatom blooming periods from March and July to April-June and December. The major dominant species was Aulacoseira species during the investigated periods and especially Stephanodiscus species was a major dominant species during winter. The dominance of Aulacoseira species and Stephanodiscus species in the Paldang Dam Reservoir meant that the water body revealed a eutrophic status to a considerable extent.

Keywords : Aulacoseira, blooming, diatom community, Stephanodiscus, Paldang Dam Reservoir