Long-term Variations of Phytoplankton Community in Coastal Waters of Kyoungju City Area

Abstract

Starting from the February 2008 till the end of November 2014, abundance of phytoplankton and their composition living in the coastal waters of Kyoungju city were investigated. Environmental and biological properties were also observed at 10 different stations on a seasonal basis. Due to the environmental variables, fluctuating pattern was appeared during the entire period of observation with different degree, as compared to those found in other costal waters in the East Sea. The concentration of phosphate was turned out to be very low which was even less than threshold level in the study area. Phytoplankton community structure was dominated by diatoms (both micro-and nanoplankton fractions) for several years and seasonal succession was also relied on the diatoms. The importance of dinoflagellates in the community was relatively low. Abundance of phytoplankton was heavily affected by physical factors in the surface water, however, affected more by chemical factors including nutrients in the deep water. For periods of this study, the phosphate concentrations was observed in an extremely low, which indicates that the main limiting factor affecting phytoplankton growth could be phosphate.

Eutrophication Driven by Aquaculture Fish Farms Controls Phytoplankton and Dinoflagellate Cyst Abundance in the Southern Coastal Waters of Korea

“…Phytoplankton samples were transferred to settling tubes and settled for 48 h in the dark. The supernatant was then removed to yield 10 mL of concentrated samples [45]. Then, 1 mL of the final sample was mounted on a Sedgewick-Rafter counting chamber to quantify the phytoplankton assemblages using a light microscope (Olympus CH30; Olympus Corporation, Tokyo, Japan).…”

Relationship of Spatial Phytoplankton Variability during Spring with Eutrophic Inshore and Oligotrophic Offshore Waters in the East Sea, Including Dokdo, Korea

“…33-39, 46, and 47) known to have an island effect; and the area between Ulleungdo and Dokdo which remains oligotrophic (UD, Stns. [40][41][42][43][44][45]. Samples from some stations were also collected on the return trip to determine if there was a change in phytoplankton abundance over time.…”

“…It is, therefore, uncertain if C. socialis is a eurythermal species or if different strains of C. socialis have different thermal tolerances [37,38]. This species is present year-round off the coast of Korea but is most dominant in the East Sea and the coast of Jeju when water temperatures are low [39,40]. This suggests the C. socialis in this region could be a strain that is tolerant of low temperatures [41].…”