The source and significance of two nutrients,nitrogen and phosphorous,were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay,in autumn 2004.This modified dilution method accounted for the phytoplankton growth rate,microzooplankton grazing mortality rate,the internal and external nutrient pools,as well as nutrient supplied through remineralization by microzooplankton.The results indicated that the phytoplankton net growth rate increased in turn from inside the bay,to outside the bay,to in the Xiaogang Harbor.The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d^-1 outside the bay,0.42 and 0.32 d^-1 inside the bay and 0.98 and 0.62 d^-1 in the harbor respectively.Outside the bay,the remineralized nitrogen (K_r=24.49) had heavy influence on the growth of the phytoplankton.Inside the bay,the remineralized phosphorus(K_r=3.49) strongly affected the phytoplankton growth.In the harbor,the remineralized phosphorus (K_r=3.73) was in larger demand by phytoplankton growth.The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure,microzooplankton grazing mortality rates and environmental conditions.It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.

Based on the data of the Jiaozbou Bay Ecosystem Dynamic Research,cell volume and surface area of 87 common phytoplankton species in China sea waters were calculated with assignment of the similar geometric form.The cell plasma volume,live weight,carbon mntent and nitrogen content were also calculated with the methods of Mullin et al.(1966),5trathmann(1967),Eppley et al.(1970),arid Taguchi(1976).After comparing these methods,we chose the method of Eppley et al.(1970) as the best method for calculating phytoplankton carbon content in China sea waters.

Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen, China, were investigated in this study. Species composition of the phytoplankton community in these waters changed greatly since the 1950s. The numbers of Dinophyta species increased significantly, although Bacillariophyta species are generally dominant. The succession of dominant species in phytoplankton community is obvious:large-size dominant species such as Biddulphia sinensis of the 1950s were gradually replaced by small-size ones such as Cyclotella striata and Nitzschia closterium, and species that still maintain dominant such as Skeletonema costatum are also small ones, leading the whole phytoplankton community of smaller size. Cell density of phytoplankton community increased greatly, among which cell density of the most dominant species Skeletonema costatum have been increasing in exponent function. Margalef index of phytoplankton community decreased, indicating decline of biodiversity of the community, and dominant character of Skeletonema costatum increased. Generally, the structure of the entire phytoplankton community is becoming more and more singular and unstable, which makes the occurrence of red tides more frequent. The succession in the phytoplankton community is related to the long-term changes in marine environment, influenced by human activities and global climate changes, especially the increases of nutrient content.

The results from the 38 cruises of phytoplankton surveys in the red tide outburst area in the Xiamen Harbor in 1987 indicate 41 species of red tide organisms among 110 species of phytoplankton identified.Species tomposition was dominant by eurytopic species and warm water species.Species diversity apparently changed with (cold and warm) seasons.There was a high diversity in warm seasons, 63 species in August.Average annual number of phytoplankton reached 1 119×10³ ind./dm³ which was 2 to 2.6 times that in 2 control monitoring stations.The number of phytoplankton in horizonal distribution displayed an obvious increasing tendency from the harbour mouth to the inner harbor.The phytoplankton number always changed with time, but with 3 peak values in the year round.The daily change of the phytoplankton number with tide exhibited a negative relativity.Moreover phytoplankton species and their number showed a vertical movement during day and night.Futhermore, 10 predominant species changed with seasons was noted in the present paper.

Remote sensing applications are important in the fisheries sector and efforts were on to improve the predictions of potential fishing zones using ocean color. The present study was aimed to investigate the phytoplankton dynamics and their absorption properties in the coastal waters of the southeastern Arabian Sea in different seasons during the year 2010 to 2011. The region exhibited 73 genera of phytoplankton from 19 orders and 41 families. The numerical abundance of phytoplankton varied from 14.235×10³ to 55.075×10⁶ cells/L. Centric diatoms dominated in the region and the largest family identified was Thalassiosiraceae with main genera as Skeletonema spp., Planktionella spp. and Thalassiosira spp. Annual variations in abundance of phytoplankton showed a typical one-peak cycle, with the highest recorded during premonsoon season and the lowest during monsoon season. The species diversity index of phytoplankton exhibited low diversity during monsoon season. Phytoplankton with pigments Chlorophyll a, Chlorophyll b, Chlorophyll c, peridinin, diadinoxanthin, fucoxanthin, β-carotene and phycoerythrobilin dominated in these waters. The knowledge on phytoplankton dynamics in coastal waters of the southeastern Arabian Sea forms a key parameter in bio-optical models of pigments and productivity and for the interpretation of remotely sensed ocean color data.

本研究通过对浮游植物物种组成和水文要素（温度和盐度）的分析对黄海(31.20°-39.23°N,121.00°-125.16°E)进行了生态分区。航次于2014年4月28日～5月18日在调查海区对40个站位进行了浮游植物样品采集，采用Utermöhl方法对样品进行了浮游植物种类鉴定分析，共计173个样品，鉴定得到7门81属188种浮游植物。表层浮游植物细胞丰度峰值集中在朝鲜半岛西侧和辽南-西朝鲜湾沿岸区域，高值区主要由硅藻和蓝藻共同刻画，主要优势物种为新月柱鞘藻（Cylindrotheca closterium）、派氏集胞藻（Synechocustis pevalekii）、尖尾蓝隐藻（Chroomonas acuta）、具槽帕拉藻（Paralia sulcata）、太平洋海链藻（Thalassiosira pacifica）和米氏凯伦藻（Karenia mikimotoi）等。对前十种优势种进行了多维度分析（MDS）和结聚类分析，并结合调查海区的水文要素将黄海分为5个生态区（P-1～P-5）。P-I区代表北黄海辽南沿岸，浮游植物细胞丰度介于35419×10³～36162×10³ cells/L，平均为35 791×10³ cells/L，其中占总浮游植物生物量99.84%的是蓝藻；P-Ⅱ区代表黄海西海岸近岸，浮游植物总细胞丰度介于2×10³～48×10³ cells/L，平均为24×10³ cells/L，占总浮游植物生物量63.69%的是硅藻；P-Ⅲ区代表长江冲淡水水域，浮游植物总细胞丰度介于10×10³～37×10³cells/L，平均为23×10³cells/L，其中占总浮游植物生物量73.14%的是硅藻；P-IV区代表受黄海暖流影响区域，浮游植物总细胞丰度介于5×10³～82×10³ cells/L，平均为27×10³ cells/L，其中占总浮游植物生物量64.17%的是硅藻；P-V区代表北黄海的冷水团水域，浮游植物总细胞丰度介于41×10³～8 912×10³ cells/L，平均为1763×10³ cells/L，其中占总浮游植物生物量89.96%的是硅藻。综上，黄海春季浮游植物群落结构在各生态区间差异明显。通过对黄海春季浮游植物优势种与环境要素间进行的典范对应分析（CCA）得到了影响浮游植物分布的主要环境因子依次是硝酸盐、温度和盐度。

The results of an investigation carried out during June 2005 to May 2007 on physico-chemical parameters, species composition and community structure of phytoplankton including Chlorophyll a (Chl-a) at the Coleroon coastal waters (Southeast coast of India) are reported. Air and surface water temperatures (℃) varied from 25.1 to 30.1 and from 24.5 to 28.5 respectively. Salinity values varied from 6 to 28.5 and the pH ranged between 7.0 and 8.3. Variation in dissolved oxygen content was from 3.1 to 7.5 mg/dm³ while the light extinction coefficient values (LEC) ranged between 3.1 and 10.1 cm. The ranges of inorganic nutrients (μmol/dm³) viz., nitrate, nitrite, phosphate and silicate were 10.1-23.4, 1.2-8.9, 0.2-3.1 and 55-125, respectively. The ranges of Chlorophyll a (μg/dm³) values was 2.0-7.5. Presently, 124 phytoplankton species representing different classes viz:Bacillariophyceae (77), Dinophyceae (19), Cyanophyceae (15), Chlorophyceae (10) and Chrysophyceae (3) were recorded. The phytoplankton cell abundance varied from 0.290 to 111.662 cells/cm3, with peak diversity (3.38 bits/ind.) during summer season. The maximum abundance was found during summer season coinciding with the stable hydrographical conditions. The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters. Canonical Correspondence Analysis (CCA) was applied in this paper for discriminating environmental factors having effect on phytoplankton community at species level. Coleroon coastal water is subjected to long term fluctuations in physico-chemical parameters depending upon the seasonal tidal amplitude and freshwater influx resulting in a continuous exchange of organic, inorganic, plant and animal matters.

黄海是位于大陆架上的一个半封闭的浅海，黄海冷水团是黄海一个重要的海洋现象。黄海冷水团的季节性生消对生源要素（如磷元素）以及浮游植物营养盐胁迫等生物过程产生重要的影响。在本研究中，2006年4月10月以及2007年3月和8月的四个航次中，作者调查了黄海冷水团对于浮游植物磷胁迫的季节性变化。应用群落水平和单细胞水平碱性磷酸酶相结合的分析方法，研究了该海区浮游植物群落变动与磷胁迫的关系，探讨了黄海浮游植物对磷的生态生理响应。黄海冷水团的生消对于黄海的无机磷酸盐浓度和群落水平的浮游植物碱性磷酸酶浓度都呈现显著的季节性影响。在A和B断面上，浮游植物碱性磷酸酶浓度在2007年8月最高，而在2007年3月最低。通过单细胞水平碱性磷酸酶活力检测来看，浮游植物优势种在3、4、10月均是硅藻为优势类群，而在夏季8月是甲藻为优势类群，且浮游植物的磷胁迫也存在明显的季节变动。浮游植物群落水平的磷胁迫呈现夏季最强，春季最弱，甲藻比硅藻更容易诱导表达碱性磷酸酶，这表明甲藻更容易受到磷胁迫。综合浮游植物优势类群和代表种的标记情况，发现黄海表层浮游植物单细胞水平的磷胁迫在8月最强，而在4月最弱。不同浮游植物诱导表达碱性磷酸酶的特性有差异，其磷胁迫水平也存在种间差异，像黄海的亚历山大藻（Alexandrium）和斯克里普藻（Scrippsiella）等甲藻可能常年处于磷营养盐胁迫状态。

Analysis of high-resolution 4 km sea surface temperature, Chlorophyll a (Chl a), and wind datasets provides a detailed description of the spatio-temporal seasonal succession of phytoplankton biomass in the Red Sea and Gulf of Aden. Based on Moderate Resolution Imaging Spectroradiometer on-board aqua platform (MODIS Aqua) data andsynoptic observations in the Red Sea, Chl a varies from north to south, with the northern part appearing to be oligotrophic. This is likely due to the absence of strong mixing and low nutrient intrusion in comparison to the southern part during winter. In the Gulf of Aden, the emergence of upwelling cell is clearly evident along the coast of Yemen, and is only distinct from the summer-autumn seasons. Most notable is the pulsating nature of the upwelling, with warm and cold events clearly distinguished with phytoplankton response to this physical forcing also evident. The phytoplankton biomass distribution varies considerably between the two regions of study. In both study areas, water temperature and prevailing winds control nutrient concentrations.

The West Pacific Ocean is considered as the provenance center of global marine life and has the highest species diversity of numerous marine taxa. The phytoplankton, as the primary producer at the base of the food chain, effects on climate change, fish resources as well as the entire ecosystem. However, there are few large-scale surveys covering several currents with different hydrographic characteristics. This study aimed to explore the relationships between the spatio-temporal variation in phytoplankton community structure and different water masses. A total of 630 water samples and 90 net samples of phytoplankton were collected at 45 stations in the Northwest Pacific Ocean (21.0°–42.0°N, 118.0°–156.0°E) during spring and summer 2017. A total of 281 phytoplankton taxa (>5 μm) belonging to 61 genera were identified in the study area. The distribution pattern of the phytoplankton community differed significantly both spatially and temporally. The average abundances of phytoplankton in spring and summer were 797.07×10² cells/L and 84.94×10² cells/L, respectively. Whether in spring or summer, the maximum abundance always appeared in the northern transition region affected by the Oyashio Current, where nutrients were abundant and diatoms dominated the phytoplankton community; whereas the phytoplankton abundance was very low in the oligotrophic Kuroshio region, and the proportion of dinoflagellates in total abundance increased significantly. The horizontal distribution of phytoplankton abundance increased from low to high latitudes, which was consistent with the trend of nutrient distributions, but contrary to that of water temperature and salinity. In the northern area affected by the Oyashio Current, the phytoplankton abundance was mainly concentrated in the upper 30 m of water column, while the maximum abundance often occurred at depths of 50–75 m in the south-central area affected by the Kuroshio Current. Pearson correlation and redundancy analysis (RDA) showed that phytoplankton abundance was significant negatively correlated with temperature and salinity, but positively correlated with nutrient concentration. The phytoplankton community structure was mainly determined by nutrient availability, especially the N:P ratio.