| Title |
Identification of Red Tide-causing Organism and Characteristics of Red Tide Occurrence in the Oncheon Down Stream, Busan |
| Authors |
김미희 ( Mi-hee Kim ) ; 지화성 ( Hwa-seong Ji ) ; 조정구 ( Jeong-goo Cho ) ; 조순자 ( Sunja Cho ) |
| DOI |
https://doi.org/10.15681/KSWE.2018.34.3.285 |
| Keywords |
Cryptomonads; Molecular approach; Red tide; Tidal river; Water quality |
| Abstract |
This study was performed in order to identify the red tide-causing organism and to understand the characteristics of the water quality during the winter of 2015 and 2016 in the Oncheon stream, a tidal river in Busan, where red tide often occurs in the wintertime. Two sites were selected on the stream and the surface water was sampled a total of 28 times during the experimental period. Twelve water quality characteristics, including water temperature, pH, DO, COD, total-N (T-N), total-P (T-P), and salinity were analyzed in order to test water quality. The cell numbers of cryptomonads were counted directly by microscopic observation. The nucleotide sequences of the partial 28S rRNA gene and psbA gene from metagenomic DNA, derived from each sampling site, were analyzed. According to the results, the alga most responsible for the bloom was identified as Teleaulax OC1 sp., which belongs to the cryptomonads. Three items of chl-a, pH, and DO were positively correlated with the cell numbers of the cryptomonads counted at the upper stream of the tidal area (St 1) while eight items of chl-a, TOC, BOD, total-N, COD, SS, pH, and DO were positively correlated with the cells located at the junction between the stream and Su-young river (St 2) in the order. |