강수기 양자강 하구 주변 표층해역의 해양환경과 식물플랑크톤 군집 분포 특성

A Marine Environment and Phytoplankton Community in the Adjoining Sea of Yangtze River of the East China Sea in the Rainy Season 2005

We investigated the characteristics of the marine environment and phytoplankton community of surface in the adjoining sea of Yangtze river of the East China Sea in June 2005. According to the analysis of a T-S diagram, three characteristic of water masses were identified. We classified them into the mixed water mass by the Chinese continental coastal waters and Taiwan/Tsushima warm current, Chinese continental coastal waters and Taiwan/Tsushima warm current. The first water mass was characterized by high water temperature, low salinity, low density and very high Chl-a concentration. The second one was characterized by high water temperature, low salinity, low density and high Chl-a concentration and the last one was characterized by low water temperature, high salinity, high density and low Chl-a concentration. The phytoplankton community identified a total of 95 species belonging to 43 genera. The dominant species was 3 species, that is, mainly centric diatom, Skeletonema costatum in the Chinese continental coastal waters. The others one, one dinoflagellates, Prororcentrum donghaiense and one silicoflagellates, Dictyocha speculum var. otonaria in warm current regions. Standing crops of phytoplankton and Chl-a concentration were very high with ranged from 5.9 x 103 cells/L to 1.1 x 106 cells/L, and 2.90 ㎍/L to 26.40 ㎍/L, respectively. Phytoplankton productivity in the East China Sea was controlled by the discharge of Yangtze river waters which include a high concentrations of nutrients.