于1994～1998年期间调查了浮游植物生产的生源气候气体二甲基硫（DMS）及其前身二甲基硫丙酸（DMSPp）在我国胶州湾、芝罘湾、东海的分布状况及其影响因素。结果表明，自然海区中二者浓度都存在明显的时空变化。地理分布规律是，高值出现在沿岸海区和陆架海区，低值出现在外海特别是贫营养海区。就不同季节而言，高值出现在春季或夏季，低值出现在秋季。DMS或DMSPp的分布在大尺度上主要受海流和水团的影响，而在小尺度上营养条件和生物因子则更重要。 在近岸海区，硅藻是DMS和 DMSPp的重要贡献者。研究海区硝酸盐与DMSPp的关系有两种情况：当硝酸盐浓度低于1μmol/L时，二者为正相关，硝酸盐浓度高于这个阈值时，二者为负相关。表明浮游植物细胞中二甲基硫丙酸作为渗透压调节物质其含量受到氮源可得性的调控。此外，研究结果还显示，生活污水入海、海水养殖等也对DMS和DMSPp的浓度分布有一定影响。

Comperison of the abundances of heterotrophic bacterina in the East and Soth China Seas By stancare epifluorescence microscopy and flow cytomety revealed that pProchlorococcus was miscounted as hetertophic bacteria in DAPI stained sampies. This could result in 5-31% overstimations of heterotrophicbacterial abundance in the study areas.

Measurements of ammonium and nitrte uptakes bynatural phytoplankton assemblages from Jiaozhou Bay at various combinations of amencnium and nitrate concentations with 15N tracef techniques showed that uptake rate of cither nitrogen was influenced by the presence of the other but that the influence of ammonium on nitrate uptake was much greater that thatof nitrate om ammonmium uptake. The influence mechanism of ammonimum on iitrate uptake marifested as competition at lower concemtrations and as inhibition at higher concentrations (ammocium concentration>0.6umol/L). but no total inhibtion appeared within the concentration ragen of the eperiments (0-10 uml/L). The influence of nitrate on ammonoum uptzake seems to be a results of competiotion for uptake sites on the cell surface. In view of the in situ nutrient concentration in the given marine emironment, it is believed that both nitrogen souers are utilzed by phytoplankton. Nitrate uptake in the presence of ammorium and ammonoum uptake in the pressence of nitrate are exprssed by a non-lincurly and a linearly calibrated mMichaelis -Menten equation respectively. In addition, A non-linear fratio model is given withic may be useful in practicl studies on newproduction in Jiaozhou Bay.