【摘要】 2002年8月、11月、2003年2月和5月,在三门湾进行了4个航次生物、化学和水文等专业综合调查。根据采集的浮游动物样品的分析鉴定及海上现场实验结果,对浮游动物的群落组成、生物量、丰度、多样性指数的分布和季节变动及其浮游动物对浮游植物的摄食影响进行研究。结果表明,三门湾浮游动物有67属,89种,16类浮游幼体,主要可划分为4个生态类群:以近岸低盐类群为主,其优势种为中华哲水蚤Calanus sinicus、真刺唇角水蚤Labidocera euchaeta、捷氏歪水蚤Tortanus derjugini、太平洋纺锤水蚤Acartia pacifica、中华假磷虾Pseudeuphausia sinica和百陶箭虫Sagitta bedoti等,半咸水河口类群、暖水性外海类群和广布种相对较少。浮游动物生物量和丰度的平面分布趋势除了夏季有所差异外,其它季节基本一致。2月份和5月份,浮游动物生物量和丰度,从湾顶向湾口呈逐渐增加趋势;8月份,湾口区生物量最高,而丰度高值区出现在湾顶部;11月份,生物量和丰度的平面分布相对均匀。浮游动物种类多样性指数有明显的季节变化,其动态变化与浮游动物种数和丰度的变化一致。微型浮游动物对浮游植物存在摄食压力,且有季节变化,摄食率的变化在0.18~0.68d-1,微型浮游动物的摄食率低于相同季节的浮游植物生长率。微型浮游动物对浮游植物摄食压力的变化范围为16.1%~49.1%d-1,对初级生产力摄食压力的变化在58.3%~83.6%d-1。11月份,微型浮游动物对浮游植物和初级生产力的摄食压力均出现最高值。更多还原

【Abstract】 The species composition,biomass,abundance and species diversity of zooplankton were determined for samples collected from 12 stations in Sanmen Bay in four cruises from August 2002 to May 2003.Phytoplankton growth and microzooplankton grazing rates were measured by the dilution technique,in which samples were taken at the beginning and end of the experiment for chlorophyll a concentration.We have also analyzed the spatial and temporal variation of zooplankton and its relationship with environmental factors.The results showed that the zooplankton in Sanmen Bay could be divided into 4 ecological groups,which were named coastal low saline species,estuary brackish water species,off shore warm water species and eurytopic species,respectively.A total of 89 species of zooplankton belong in 67 genera and 16 groups of pelagic larva were identified in Sanmen Bay.The coastal low saline species was the dominant ecotype in the study area,and the dominant species were Calanus sinicus,Labidocera euchaeta,Tortanus derjugini,Acartia pacifica,Pseudeuphausia sinica and Sagitta bedoti.There was considerable seasonal variation in zooplankton biomass and abundance in the surveyed area.The peak of biomass appeared in August,followed by November and May,and the lowest biomass appeared in February.Similarly,the highest abundance of zooplankton was observed in August,followed by May,November and February.There were similar horizontal distribution patterns for the biomass and abundance of zooplankton in February and May,in which they both increased from the upper of the bay to the lower of the bay in February and May.However,there were different horizontal distribution patterns for them in August.The peak of biomass appeared in the lower of the bay,while the highest abundance of zooplankton was observed in the upper of the bay in August.Biomass and abundance were distributed evenly in Sanmen Bay in November. Moreover,there was marked seasonal variation in the species diversity of zooplankton,which was conformable to the abundance of zooplankton.Results from the dilution experiments indicated that there was grazing pressure of microzooplankton on phytoplankton in Sanmen Bay throughout the year,though the rate of microzooplankton grazing on phytoplankton varied seasonally.Estimates for phytoplankton growth rate ranged from 0.25 to 0.89d^-1,while microzooplankton grazing rate varied between 0.18 and 0.68d^-1 in different seasons. The growth rate of phytoplankton surpassed grazing rate of microzooplankton in all seasons.Microzooplankton grazed phytoplankton standing stock at a rate of 16.1 to 49.1% d^-1 and the grazing pressure of microzooplankton on phytoplankton primary production ranged from 58.3 to 83.6% d^-1 in different seasons.更多还原