국내 주요항만에서 식물플랑크톤 군집에 영향을 주는 환경요인

Abstract

To understand the environmental factors affecting dynamics of phytoplankton communities at the busiest ports (Busan, Ulsan, Incheon and Gwangyang) of Korea, we seasonally investigated the physico-chemical factors and phytoplankton assemblages from February 2007 to November 2008. The majority of the phytoplankton communities were diatoms (78%). The highest abundance of diatoms were observed at Busan in summer 2007, and at Ulsan in spring 2007. Cheatoceros debilis and Ch. pseudocrinitus occupied over 60% diatoms at Busan, and Detonula pumilia dominated at Ulsan port. The port of Incheon and Gwangyang is characterized as eutrophic and semi-enclosed environment. The abundance of diatoms peaked in winter when Skeletonema costatum dominated with lower salinity, higher concentrations of chemical oxygen demands and total suspended solid at Incheon and Gwangyang ports compared to ports of Busan and Ulsan. When diatoms bloome, abundance of diatoms were observed with relatively low concentrations of silicate and nitrate (p<0.001), indicating prosperous uptake of dominated diatoms. The next dominant group dinoflagellates distributed frequently at Busan, Ulsan and Gwangyang ports in summers, when their abundance was significantly correlated with increasing temperature and decreasing salinity (p<0.05). Also, concentrations of phosphate was high (>1 μM) at the four ports in summers. Exceptionally, abundances of dinoflagellates occ