| 摘要: |
| 浮游植物生物量与生产力是海洋生态系食物网的结构与功能的基础环节，是供养其摄食者——浮游动物的物质基础，从而直接或间接地影响海区鱼、虾、贝等经济渔业资源的变动。对浮游植物粒度分级生物量与生产力的研究有助于从更深层次上研究海洋生态系自然群落结构、功能及其环境调控，并可对了解其捕食者群体的特性和营养关系提供重要信息。
渤海是一个半封闭的浅海，生态环境的季节变化显著，同时渤海周围又是人口相对集中，工农业生产较为发达的区域，易受人为因素的影响。20世纪80-90年代初，科学家们曾在渤海进行过不少初级生产力的观测(费尊乐等，1988；朱明远等，1993；吕端华等，1999)，但该海域浮游植物生物量与生产力粒度结构方面的资料尚为欠缺。而近年来渤海生态环境日趋恶化，渔业资源严重衰退，因此在该海域进行生态系统动力学，特别是浮游动物种群动力学的研究时，必须同步开展初级生产力结构的动态变化及其控制过程研究。
本研究是国家自然科学基金重大项目“渤海生态系统动力学与生物资源持续利用”的一个重要组成部分，旨在研究渤海春末、夏初对虾产卵期浮游植物现存生物量和初级产力的粒度结构、周日和空间变化及其与环境之间的关系，特别是浮游动物摄食之间关系，从而为渤海生态系统动力学模式的建立和生物资源的可持续利用提供科学依据。 |
| 关键词: 浮游植物 初级生产力 粒度分级 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金重大项目，49790010号 |
|
| SIZE-FRACTIONATED PHYTOPLANKTON STANDING STOCK AND PRIMARY PRODUCTION IN BOHAI SEA DURING LATE SPRING |
|
Ning Xiuren1, Liu Zilin2, Cai Yuming2, Liu Chenggang2
|
|
1.Key Laboratory of Ocean Dynamic Processes & Satellite Oceanography, SOA;2.Second Institute of Oceanography, State Oceanic Administation
|
| Abstract: |
| During June 1997 cruise by the R/V Science No.1, observations on temporal and spatial variations of size-fractionated phytoplankton standing stock and primary production were carried out in the Bohai Sea. Size-fractionated chlorophyll a and primary production, PAR (photosynthetically available radiation), as well as the related physico-oceanographic and zooplanktonic parameters were measured at five time-series stations representing sub-areas of the sea.
Results obtained showed that there were marked spatial zonation of chlorophyll a and primary production in the Bohai Sea. The values in Laizhou Bay, Liaodong Bay and Bohai Bay were high and appeared closely related with tidal fluctuations, i.e. high chlorophyll a concentration occurred during high tide in Laizhou Bay, and during low tide in Liaodong Bay and Bohai Bay. In the mouth and the central region of the Bohai Sea, the values were relatively low and no relationship with tidal fluctuation could be found. Chlorophyll a concentration vertically decreased from surface to bottom in Liaodong Bay and Bohai Bay, while it increased in Laizhou Bay, the mouth, the central region of Bohai Sea, and maximized at the bottom.
Size-fractionation results showed that nano-and picoplankton (< 20μm) predominated in the Bohai Sea phytoplankton communities during late spring. The average contribution to total chlorophyll a in each station was 76%-95% (mean=87%). The contribution of net (>20μm), nano-(2-20μm) and picoplankton (<2μm) were 13%, 63% and 24% to total production, and 9%, 53% and 38% to total chlorophyll a, respectively. It proved the importance of nano-and picoplankton in phytoplankton communities in the Bohai Sea ecosystems.
The paper also discussed the factors, such as light intensity, zooplankton grazing pressure, etc. governing standing stock and production of phytoplankton in the Bohai Sea. |
| Key words: chlorophyll a primary productivity |
