PHYTOPLANKTON AND EUTROPHICATION IN THE SOUTH HAN RIVER, KOREA
Kuang Qijun(Institute of Hofrobiology, the Chinese Academy of Sciences, Wuhan, 430072)Kim Bomchul(Kangulcon National University, Chunchon, 200 -701, R. O. K )
The ecological features of phytoplankton community including species composition, dominantspecies, cell density, biomass and diversity index, were preliminarily studied at 12 sampling stations in the South Han River, Korea. Green algae ranked first in species richness, with 54 species(51. 4 % of the total recorded taxa), followed by diatoms and blue-green algae, with 28 and 13species (26. 7 % and 12. 4 % ) respectively. Other four phyla contributed 10 species (9. 5 % ) altogether. Blue-green algae contributed most in cell density with a maximum percentage of 70. 7 %and a minimum of 36 %. Green algae ranked the second and diatoms the third. On the contrary,diatoms led in biomass, followed by green algae and blue-green algae. The maximum and minimum percentage of diatoms in biomass was 93. 7 % and 39. 3 % respectively. The mean cell density and biomass of phytoplankton in the river reached 8. 3 x 106 cells per litre and 4. 2 mg per litre.Analysis on the species diversity with 3 index equations indicated that the community structureswere not much different among the 12 stations. The results of physico-chemical analysis of theriver shows that the TP and TN concentrations have reached the eutrophic or hypereutrophic level.