한국 동해 남부 연안생태계 연구 1 . 1994 년 9 월에 있어서의 식물플랑크톤의 군집구조와 1 차 생산력 = The Ecosystem of the Southern Coastal Waters of the East Sea , Korea 1 . Phytoplankton Community Structure and Primary Productivity in September , 1994

다국어 초록 (Multilingual Abstract)

Phytoplankton community and primary productivity have been investigated in a fall season in the southern coastal waters of the East Sea, Korea. A strong thermocline formed at the 20-60m layer and a cold water mass also existed in the bottom around Yong-il Bay. The offshore of the surveyed area was likely to be influenced by relatively warmer water, whereas the inshore represented higher primary productivity with lower water temperature and lower salinity. A total of 133 species of phytoplankton occurred, representing 107 spp. of diatom, 23 spp. of dinoflagellate, 3 spp. of silicoflagellate. Skeletonema costatum and Asterionellepsis glacialis were most predominant with more than 30% dominance ratio, while Leptocylindrus danicus was also dominant at all transect lines. Standing crops of phytoplankton ranged from 2.7×10³ to 141.6×10³ cells ℓ^(-1). Chlorophyll a concentration varied with stations and layers, but the 30-50m layer showed maximum with about 1.18㎍ℓ^(-1) rather than at the surface layer. It is believed that the maximum in standing crops and chlorophyll of phytoplankton formed at the 20-50m layer above the thermocline during the survey. Phytoplankton primary productivity ranged from 0.32 to 3.04㎎C m^(-3) hr^(-1), showing higher at the inshore than at the offshore. The range of integrated primary productivity was 263.3-1085.5㎎C m^(-2) day^(-1) for the euphotic layer. Photosysthesis rates varied with the range from 0.76 to 8.04㎎C mgChl a^(-1) hr^(-1). Phytoplankton photosynthesis at the inshore was saturated at lower irradiance(15-35% of surface) and showed higher efficiency. Thus, it revealed that the phytoplankton community probably adapted to the middle of euphotic layer because the depth of mixing layer became thinner due to the formation of thermocline.