The Studies On The Distribution Of Pigments In East China Sea Sediments Of High Frequency Habs Areas

On the basis of previous achievements， the study established the analyticalmethod of high performance liquid chromatography（HPLC） for pigments insedments. Horizontal and Vertical distribution of pigments in sediments andSedimentary Records were investigated. The results were as follows:Total TOC and TON in pigments of sediments in high frequency HABsareas of East China Sea gradually increase from North to South. And they reach thepeaks in Zhoushan Islands and southward areas of Xiangshan County. Surfaceanalysis of pigments of sediments shows that the study area contains rich productiveforces， the soil of eastward areas of Xiangshan provide favorable condition for dinflagellate to grow. The whole area contains a certain volume of diatom，prasinophytes， cryptophytes， cyanobacteria， etc. C/N ratio indicates that theorganic matter in the area mainly comes from the local area， rather the land input.The distribution of Total TOC and TON in the neighborhood of high frequencyHABs areas in East China Sea grows from Hangzhou gulf， Zhoushan islands toXiangshan County. The maximum value occurred near the coast of the XiangshanCounty. Spatial analysis of pigments of sediments tells us that space within30cm ofzc17stance have higher ancient productivity and abundant din flagellate. The coastalarea within30cm of Zhoushan islands contain higher distribution of chrysophytesand diatom. Characteristic ratio of pigments of sediments in cryptophytes andprymnesiophytes is the highest near Xiangshan County. The tendency of distributionof lutein demonstrates that Hangzhou gulf and land input of Yangzi River has hadgreat influence on the distribution.Impacted by the flood of East China Sea basin in1998， much terrigenousmaterial was washed into the Yangtze River estuary， which enabled the TOC andTON reach its reflection point of high value. Therefore， the average sedimentationspeed of the columnar-shaped za3near the Yangtze River off-shore reaches0.827cm/a.In the Za3sedimentary column，some pigments share the similarity in their verticaldistribution. For instance， impacted by the polarity， c3， peridinin， violaxanthin can be easily degraded in the aerobic zone within the10cm sedimentation surface butcan only be slowly degraded within the20cm sedimentation surface where most otherpigments of segment can be easily degraded. Chl c2， peridinin， fucoxanthin andchla are found to be quite different in their distribution， which demonstrates that thevertical distribution feature of pigments is connected to the degradation speed of thepigment polarity in sediment. Diatoxanthin， zeaxanthin， chl b， DV chl a， andβ-carotene etc can be detected in the whole sedimentation column， illustrating thatthese pigments possess the higher degradation ability in the sedimentationenvironment. The results showed that the number of phytoplankton in the East ChinaSea had increased constantly since1950s and appeared some outlier.This couldindicate that nutrients in this area had increased constantly. The productionincreased under the influence of terrestrial nutrients input during1950s-1980s.Itshowed that nutrients had a positive correlation with phytoplankton community. Thediatoim production varied little while other algae increased，such as dinoflagellate，cryptophytes and chlorophytes.