Responses of phyto- and zooplankton to liming in a small acidified humic lake

Liming resulted in an immediate and transitory decrease of plankton biomass and phytoplankton primary production in the limed part of an acidified humic lake. In the longer term liming has changed species composition and dominance of phyto- and zooplankton. Due to increased transparency and improved oxygen conditions plankton biomass peaked deeper in the water column after liming. During the three years post-liming period phyto- and zooplankton communities have changed less than reported in several other studies. This is largely because liming was carried out well before the collapse of perch population, which has controlled zooplankton both in the pre- and post-treatment period.     

大连常江澳浮筏养殖贝类的饵料结构与浮游植物的关系

１９９５年６月２９日至１０月２２日对大连市金卵眍常江澳（大李家湾）浮筏贝类养殖水域及近岸海域进行了调查。研究了该海域养殖贝类的胃含物民浮游植物的种类组成、个体大小与数量分布情况,并对两者关系作了初步分析。结果表示,养殖贝类胃含物及肠道食物残余主要为硅藻和有机碎屑;海区浮游植物的种类组成和个体大小适宜贝类摄食;饵料生物的种类丰富、数量充足,适于贝类生长及养殖需求。     

刺参养殖池塘不同粒级浮游生物呼吸率和初级生产率的研究

于2008年1—6月对大连壹桥海洋苗业股份有限公司4个刺参Apostichopus japonicus养殖池塘不同粒级浮游生物的呼吸率和初级生产率进行了测定。结果表明:(1)小型、微型及超微型浮游生物的呼吸率平均值分别为0.31、0.63、0.80 mg/(L.d)(以O2计,下同),分别占各粒级浮游生物总呼吸率的17.88%、36.10%和46.02%;小型、微型及超微型浮游植物生产率平均值分别为0.27、0.59、0.64mg/(L.d),占各粒级浮游植物总生产率的18.18%、38.98%和42.84%;小型、微型及超微型浮游生物呼吸率占相应粒级浮游植物生产率的比例分别为113.90%、107.24%、124.39%。(2)>200μm、20~200μm、2~20μm和<2μm的4个粒级浮游植物叶绿素a含量的平均值分别为0.75、0.65、3.08、1.26μg/L,分别占总叶绿素a含量的13.15%、11.30%、53.63%和21.92%。     

上海城市河网冬季浮游植物功能群群落构建机制及其驱动因素研究

浮游植物是水体重要的初级生产者,其功能群特征对维持水生态系统的稳定性具有重要作用。为揭示超大型城市河网浮游植物功能群特征和构建机制,明确影响其变化的关键因子,本文选取上海19条代表性中小河道,对40个位点的浮游植物功能群特征以及环境因子开展了调查。结果表明,本研究共鉴定出浮游植物8门175种,可划分为23个功能类群,其中B、D、J、MP、P、S1、X1、X2、X3、Y为优势功能群。聚类分析发现,中小河道40个采样点可划分为低营养盐(G1)和高营养盐(G2)两个特征组,两组在Shannon-Wiener指数、Margalef指数、功能群群落组成以及环境因子方面,均存在显著差异(p<0.05)。群落距离衰减曲线分析以及校正随机率(MST)分析显示,上海河道浮游植物功能群的构建过程,受到环境过滤作用和空间扩散限制作用两方面的共同影响,且随机性过程占主导;G1组群落构建主要受环境过滤作用影响,而更高营养的G2组则主要受空间扩散作用影响。差异性分析和多元回归分析表明,水体总氮、亚硝氮、总磷、电导率和溶解氧等,是影响上海河道浮游植物功能群结构的主要环境因子。本研究为深入了解超大型城市河网水体生物多样性和生态功能维持机制,以及城市河网水生态系统保护提供了新资料。     

Estimation of gut contents of freshwater mussel, Lamellidens marginalis L.

This study examined the food organisms found in the gut of freshwater mussels, Lamellidens marginalis L. A total of 34 taxa of food organisms were recorded, out of which 30 taxa belonged to phytoplankton and four taxa to zooplankton. Both the groups comprised three families each: Cyanophyceae (blue‐green algae), Chlorophycea (green algae) and Bacillariophyceae (diatoms) constituted phytoplankton, whereas Euglenaceae, Chlamydodontidae and Brachionidae belonged to zooplankton. The total number of frequencies of phytoplankton (n=537) were almost nine times more than that of zooplankton (n=60). When blue‐green algae, green algae, diatoms and zooplankton (all the three families together) were tested for significant difference (P<0.05) following Duncan's multiple range test, the result showed only two groups. Blue‐green algae, green algae and zooplankton were not significantly different (P<0.05), forming group A, whereas diatoms were significantly different from others, forming group B. The present study showed that the maximum number of organisms that mussels feed upon belong to green algae, followed by diatoms, blue‐green algae and few taxa of zooplankton.     

多级生物净化系统浮游植物的分析

利用不同生物的功能特性及其间的协同作用,由水生经济植物浮床、芦苇湿地、固定化微生物膜、底栖软体动物和滤食性鱼类组成了多级生物净化系统,除芦苇湿地、滤食性鱼类外,全部设置在多级生物净化水渠中。不仅充分利用了水面,节约了材料、能源,提高了净化效率,而且有效调控和净化了养殖池塘的水质,实现了养殖排放水的循环利用,提高了养殖效益。结果显示：养殖池塘排放水经过多级生物净化后,浮游植物的生物量控制在69．114-43．832mg／L,平均减少率为13．44％～0．47％,蓝藻平均减少率为58．41％-51．63％。