Community composition and dynamics of phytoplankton at the western coast of Jeju Island, Korea

摘要

Phytoplankton community composition and dynamics with physicochemical factors were investigated monthly on the western coast of Jeju Island, Republic of Korea. A total of 291 phytoplankton species were identified, cell abundance varied between 2.95-34.39 and 2.81-26.66 x10(4) cells L-1, chlorophyll a between 0.19-1.56 and 0.07-1.51 mu g L-1 at bottom and surface, respectively. A phytoplankton bloom was observed in spring which was associated with low temperature and high salinity, NH4+ and NO3. Diatoms were 89 and 91% of total cell abundance at surface and bottom, respectively, in which Chaetoceros socialis, C. costatus, C. lorenzianus, C. pseudocrinitus and Skeletonema costatum each contributed over 10% to the total phytoplankton. In autumn, dinoflagellates contributed 49.87 and 51.57% to total phytoplankton at surface and bottom, respectively. Prorocentrum micans, P. triestinum and Gymnodinium conicum were predominant species. Such predominance of dinoflagellates is alarming for sustainable aquaculture in this area.