Korean Journal of Environmental Biology Vol. 40 No. 1 (p.54-69)

해양환경 변화로 인한 2018~2020년 동해 식물플랑크톤 크기 구조 변화

Changes in phytoplankton size structure in the East Sea 2018-2020 due to marine environment change
키워드 :
surface water temperature rises,Ocean stratification,Chl-a size fraction,phytoplankton miniaturized,phosphate restriction


서 론
재료 및 방법
   1. 현장 조사 및 시료 채집
   2. 영양염 분석
   3. 식물플랑크톤 우점종
   4. Chl-a 크기별 분석
   5. 자료 분석
결 과
   1. 물리환경
   2. 영양염 환경
   4. 우점종
고 찰
적 요
사 사


We conducted a field survey from 2018 to 2020 to analyze the spatial distribution of phytoplankton communities at 13 stations in the East Sea. The diatom Chaetoceros curvisetus appeared as the dominant species in winter, and small flagellates less than 20 μm prevailed in all seasons except winter. The seasonal average range of the micro (>20 μm), nano (20 μm≥Chl-a>3 μm), and picophytoplankton (≤3 μm) was 20.6-26.2%, 27.1-35.9%, and 40.8-49.0%, respectively. The composition ratio of nano and picophytoplankton was high at the surface mixed layer from spring to autumn when the water columns were strongly stratified. Especially, the stability of the water mass was increased when the summer surface water temperature was higher than that of the previous year. As a result, the nutrient inflow from the lower layer to the surface was reduced as the ocean stratification layer was strengthened. Therefore, the composition ratio of nano and picophytoplankton was the highest at 77.9% at the surface mixed layer. In conclusion, the structure of the phytoplankton community in the East Sea has been miniaturized, which is expected to form a complex microbial food web structure and lower the carbon transfer rate to the upper consumer stage.