| Living coccolithophores (LC) are a class of marine micro-phytoplankton which is widely distributed in the global ocean, and they are one of the marine phytoplankton functional groups which take a great part at calcification in biological groups, also they are the source of the inorganic carbon in the ocean and play an important role in the carbon cycle of the ocean.Living coccolithophores bloom occurs because of the rapid proliferation process of which can release large amounts of volatile dimethyl sulfide (DMS) and acrylic acid, which are the critical materials that can affect the climate change, particularly the regional environmental effects (greenhouse). Therefore, studying the distribution of the LC communities in China seas will play an important role in the carbon cycle and climate changing research.Based on the investigations of the communities and distribution of LC in the Yellow Sea and East China Sea in summer (20th July to 1st September) and winter (23th December to 5th February) 2009, LC species composition, cell abundance, dominant species, horizontal distribution, vertical distribution, diversity index and evenness index, and the water column integrated abundance are report in this thesis. The major results are showing in the following paragraphs.In summer 2009,21 species of the coccolithophores were found in the survey area with the dominant species Emiliania huxleyi, Gephyrocapsa oceanica, Umbellosphaera tenuis and Florisphaera profunda. In this survey, the cell abundance of coccolithophores that calcited was in 0.23～17.62×103 cells/L, with an average of 2.84×103 cells/L. In the whole survey area, most of the stations were dominated by the E. huxleyi and G. oceanica, respectively reached 36.77% and 32.90%. The distribution of the two species basically described the entire distribution of all the species of coccolithophores in the survey area. They were mostly distributed in the 35 m and 50 m water layer and they concentrated in the northern and southern survey areas. F. profunda's distribution which is different from E. huxleyi and G. oceanica was mostly distributed in the 50 m to 200 m water layer, especially at 50 m～75 m water layer of the northwestern and southeastern of the survey area. And U. tenuis concentrated more in the northern waters of the survey area with high value at 25 m depth. The water column integrated LC abundance was ranged 7.82×103～19.12×105 cells/m2, with an average of 2.39×105 cells/m2, and high values appeared in the south of the survey area.In winter 2009,20 species of the living coccolithophores were found in the survey area with the dominant species E. huxleyi, G. oceanica, F. profunda and U. tenuis. In this survey, the cell abundance of the coccolithophores which was calcited was in 0.12～35.35×103 cells/L, with an average of 3.84×103 cells/L. Compared with the summer, E. huxleyi shared the greater cell abundance value for 42.97%, and G. oceanica is consistent with the summer's share, for 32.06%. And F. profunda had a higher value than U. tenuis and ranked the third. However, the cell abundance of E. huxleyi and G. oceanic still dominated in the survey area, and they were more distributed in the 50 m to 75 m water depth. Still F. profunda was mainly located in the 50 m to the deeper water layer. The water column integrated LC abundance was in 7.82×1O3～19.12×105 cells/m2, and with an average of 2.39×105 cells/m2, and high values appeared in the central and eastern survey area.This thesis investigated and analyzed the LC community and distribution in two seasons (summer and winter) of the Yellow Sea and East China Sea, and study in the upper water column (0～200 m) on LC cell abundance, dominant species, community diversity and evenness, the water column integrated abundance, which enriched the LC studies in the coastal seas of China and also provided the basic data for understanding carbon cycle and carbon flux in China Sea waters. |
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