한국 연안해역의 Cochlodinium polykrikoides적조 발생의 특징

Occurrence Characteristics of Cochlodinium polykrikoides Blooms in the Korean Costal Waters

In this study, we investigated marine environmental conditions when Cochlodinium polykrikoides blooms occurred in the southern coastal waters of Korea, based on the reviews of 98 articles, HABs information of National Institute of Fisheries Science, and marine environmental information system of Korean Marine Environment Management Corporation. Most of C. polykrikoides blooms occurred in four sea regions, i.e., Goheung, Yeosu, Namhae, and Tongyeong in the summer, and in addition, they more frequently occurred at the eastern coast rather than at the western coast. The years were divided into two cases in terms of whether the blooms extensively occurred or did not occurred at all, but it was still unclear why they happened or did not happen. Surface water temperatures in August in these four sea regions ranged from 25℃ to 26℃ while bottom water temperatures showed a significant fluctuations with a higher temperature of 4℃ to 6℃ particularly in Goheung. Surface salinities in Yeosu were relatively lower and more fluctuating than those in the other regions owing to possibly Seomjin river flow. On the other hand, bottom salinities appeared to be stable overall, although Goheung and Yeosu were relatively lower compared to Namhae and Tongyeong. Concentrations of dissolved inorganic nitrogen (DIN) were most low and stable in Goheung at both of the surface and bottom layers while they were most high and fluctuating in Yeosu owing to possibly Seomjin river flow or adjacent industrial complex. Concentrations of dissolved inorganic phosphorus (DIP) were most high and fluctuating in Yeosu at both of surface and bottom layers while they were most low at the surface layer of Namhae but at the bottom layer of Goheung, respectively. However, concentrations of DIN and DIP did not seem to have a significance with the occurrence of C. polykrikoides blooms. Concentrations of chlorophyll a (Chl_a) were high in Goheung and Yeosu at both of the surface and bottom layers while they were low in Namhae and Tongyeong, and furthermore concentrations of Chl_a did appear a significance with C. polykrikoides blooms.