Algae. 2006; 21(1): 75-82.
Diel Vertical Distribution of Cyanobacteria in Lake Daecheong
Jong-Geun Park1*, Yeoun Suk Kim2, Jung Joon Lee3, Sung Hyun Chang3 and Jung Ho Lee3
1Water Analysis & Research Center, KIWE, KOWACO, Daejon 306-711, Korea
, 2Department of Biology, Kyungpook National University, Daegu 702-701, Korea
3Department of Biology Education, Daegu University, Kyungsan 712-714, Korea
ABSTRACT
Cyanobacteria regulate their buoyancy in response to changing environmental conditions. This process is essential for cyanobacterial development and can account for their dominance in eutrophic waters in summer. The present investigation was conducted to understand the 24-hour vertical distribution of cyanobacteria and water quality characteristics in Lake Daecheong. Water samples were collected and analyzed at depth intervals of 2 or 3 m and at an interval of three hours for a day on August 28, 2001 and September 24, 2002. In 2001 the accumulated standing crop of Microcystis spp. from surface to a depth of 6 m was 94.9%. Microcystis spp. showed no vertical migration below the thermocline. Microcystis spp. had maximum density near the surface, but shifted to 2 m depth at 2 p.m. A dense population of Anabaena spp. accumulated near the surface from 2 to 5 p.m. in 2002.
Keywords :
Anabaena spp., cyanobacteria, Lake Daecheong, Microcystis spp., vertical migration
