通过比较1985～2001年的海表温度与其间收集的现场营养盐、浮游植物和浮游动物丰度及群落结构变动信号，以及1971～1998年的中上层鱼类渔获量变动信息，发现了台湾海峡生态系统对物理环境年际变动产生的响应迹象。1997年夏季台湾海峡处于偏冷状态，南部近岸上升流强度减弱；1997年冬季正值一个较强的暖事件发展到顶峰，北上入侵暖水强度增强、浙闽沿岸冷水强度减弱。导致这两个时期营养盐分布特征改变，发生了一系列从浮游植物到浮游动物，从生物量到群落结构的异常响应，暖水性中上层鱼类渔获量则似乎呈现出ElNiÌo年偏高的趋势。根据有限的辅助证据推测，El NiÌo很可能不是控制台湾海峡海洋环境年际变动的强信号，而台湾海峡的气候-海洋-生态长期低频变动可能更多地受到东亚季风2中国边缘海系统的控制。

应用稀释法对厦门海域浮游植物生长率（k）和微型浮游动物的摄食率（g）进行了估算。结果显示：5月，西海域18测站kg分别为2.41、0.78d 21；南部海域27测站分别为2.43、1.32d 21。8月18测站kg分别为3.00、2.90d 21 27测站分别为1.94、0.91d 21。说明厦门海域作为典型的亚热带港湾，具有高的kg值。分粒级研究结果显示：8月，18测站微型浮游动物对微型浮游植物（Micro）具摄食偏好；而27测站微型浮游动物对Micro和Nano级的摄食率相近。应用流式细胞技术研究18测站微微型真核浮游植物的kg，结果表明：春季，生长率和摄食率分别为2.00、1.02d 21；夏季分别为1.52、0.96d 21。

本文研究了1997年8月、1998年2～3月、8月和1999年8月台湾海峡浮游植物生物量和初级生产力的粒级组成、各粒级生物量和初级生产力变动（包括年际变动）及其影响因子。结果表明，台湾海峡微型（简称NANO）和微微型浮游植物（简称PICO）占优势，贡献率分别达34%～48%、34%～40%，小型浮游植物（简称MI2CRO）仅占12%～27%。粒级组成和各粒级生物量存在着明显的季节和年际变化，如1997年夏季三种粒级浮游植物生物量均明显低于其它年份，PICO和MICRO组份呈1998年夏季高于1997年和1999年夏季，而NANO组份则呈1998年夏季低于1997年和1999年夏季。PICO组份对初级生产力的贡献最大，达45%～50%，NANO和MICRO组份对初级生产力的贡献相近，为19%～32%；PICO组份的同化系数明显高于NANO和MICRO组份。初步分析了初级生产的碳流途径，表明台湾海峡初级生产的碳将有25%经异养细菌的“二次”生产而进入微食物环，36%通过原生动物（主要是异养鞭毛虫）摄食“打包”作用后进入微食物环，即近60%的初级生产的碳经微食物环的两个起点分别进入微食物环，表明微型生物食物网在该海域生源有机碳转换过程中起重要作用。

Abundance, carbon biomass and composition of picoplankton along a transect (from the Pearl River estuary to Dongsha Island) in the northern South China Sea were measured by flow cytom-etry (FCM); and the vertical structure, composition variation, relationship between heterotrophic and au-totrophic picoplankton as well as the controlling mechanism of diel variation were studied. Results showed that along the horizontal direction, both Syrtechococcus (SYN) and picoeukaryote (PEUK) were highest in abundance and dominated autotrophic picoplankton in the Pearl River estuary, but decreased significantly from the estuary to offshore. Prochlorococcus (PRO) dominated autotrophic picoplankton in the offshore water, but its abundance was lower than that of heterotrophic bacteria (BAC). BAC distribution related closely with autotrophie pieoplankton, and was affected significantly by primary production. Four catego-ries, especially PRO and PEUK, were dominant in the subsurface layers, and were usually associated with the subsurface chlorophyll a maximum, which might be mainly due to their ability to live under low light intensity and weak nutrient dynamics. Based on the contribution of carbon biomass, three distinct cases of the studied waters were roughly classified. The first ease, observed in the estuary, was dominat-ed by SYN and PEUK; the second case was characterized by oligotrophic status, with the highest contri-bution of PRO in autotrophic picoplankton; the last case may relate to the cold eddy and was co-dominat-ed by PRO and PEUK. The diel variation indicated that PRO and PEUK abundance peaked late in the night, which could be due to the combined effects of tidal currents, cell division and grazing.

The bioavailability of dissolved organic phosphorus (DOP) compounds to harmful alga Prorocentrum donghaiense Lu and its 10 alkaline phosphatase activity (APA) were studied. Results showed that P. donghaiense could utilize the test DOP compounds such as glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP) and ribonucleic acid (RNA) to sustain its growth. Nutrition between the test DOP compounds and orthophosphate was comparable. P. donghaiense could utilize intracellular phosphorus to sustain growth under depletion of dissolved phosphorus. Variation of APA in different test DOP compounds was addressed; the controlling mechanism of APA in different DOP media was discussed.