Partial nomadism in large‐bodied bream (Abramis brama)

The recent focus on a common movement ecology paradigm has increased awareness about the importance of distinguishing different movement patterns for understanding their specific impact on animal ecology and evolution. One specific form of movement is nomadism, where animals move between habitats in an arrhythmic fashion. Although not yet described in detail for freshwater fish, nomadism between lakes within drainage systems could affect local lake food webs in an otherwise unpredictable fashion. In this study, we used passive telemetry to describe inter‐lake movements of 1,280 individually tagged adult benthivorous bream (Abramis brama) over nine contiguous years in a drainage system with two paired lakes. The movements can best be described as partial nomadism, where a part of the population is neither resident nor migratory, but instead moves between lakes in a variable, arrhythmic fashion, often with long residency in one lake before moving to the other. We found extensive between‐year variation in the proportion and direction of bream moving, with higher movement propensity being partly associated with lower somatic condition. Notably, movements out of lakes were significantly more in direction of the neighbouring lake than away from the paired lakes, suggesting that at least direction was not random. Since bream are important ecosystem engineers, fluctuating densities of adult bream could affect ecological stability in lakes. Our study suggests that fish populations in interconnected lakes within drainages should not be treated as isolated units, and we discuss this in relation to lake ecology and the importance for lake ecosystem management.     

不同重悬细胞法在洗涤过程中对水牛外周血单个核细胞活率的影响

为了探讨在离心洗涤水牛外周血单个核细胞（peripheral blood mononuclear cell, PBMC）过程中以移液器吹打法和晃动离心管法重悬细胞对其活率的影响。对经密度梯度离心后初步收集到的PBMC,分别用移液器吹打和晃动离心管2种方法重悬细胞,离心洗涤后对细胞活率进行计数。结果发现,移液器吹打法得到的细胞活率为（74.9±2.6）%,而晃动离心管法使细胞活率达到（98.5±0.5）%,差异极显著（P<0.01）。说明在洗涤PBMC时,晃动离心管法重悬细胞能大大提高细胞活率,可为那些对细胞活率要求高的试验提供一个较为有效的方法。     

河口区底泥中重金属再悬浮的研究进展

综述了重金属在全球主要河口区再悬浮过程中的迁移转化过程进展,并概述了用实验室模拟再悬浮的方法来判别重金属污染的来源的进展。     

鲟亲鱼培育池塘中浮游生物的组成与变化特点的研究

研究了2009年5-9月鲟亲鱼养殖池塘中浮游生物的种类组成,细胞数量、优势种组成和随季节的变化。结果显示：鲟亲鱼的活动导致养殖池塘沉积物再悬浮,水体透明度较低。浮游植物的种类组成以绿藻门（Chlorophyta）的月牙藻（Selenastrum spp．）和小球藻（Chlorella spp．）等小型个体为主,浮游植物密度1．0883×lO^7ind．／L—1．5662×lO^7ind．／L,生物量14．6438～19．2535mg/L。浮游动物以轮虫（Rotifera）和桡足类（Copepoda）为优势种群,浮游动物密度162．0000ind／L～560．0000ind／L,生物量0．3795～1．5482mg／L。研究显示,鲟亲鱼的活动是决定池塘浮游生物的群落结构变化的重要过程之一。     

Discharges and Sediments as Sources of Extracellular Alkaline Phosphatase in a Shallow Chinese Eutrophic Lake

Total alkaline phosphatase activity (APA) and soluble reactive phosphorus (SRP) concentrations were measured in municipal wastewater, and a shallow Chinese freshwater lake receiving it. Activities of Dissolved alkaline phosphatase (ADAP) in overlying and interstitial water were also analyzed monthly at three sites for several years. The lake was enriched with SRP and alkaline phosphatase by discharge of the wastewater, indicating that the inclusion of APA for estimating water pollution was reasonable. Annual data showed that APA in coarser fraction was significantly higher at the site receiving more wastewaters, both in surface and overlying water, suggesting that resuspension of enzyme most likely occurred in the basin heavily discharged. ADAP was an order of magnitude higher in the wastewater than those in lake waters, and was generally higher in interstitial water, a feature more striking at the site receiving more discharges. Besides, it was irrespectively inhibited by Na₂WO₄, L-cysteine and EDTA-Na, but stimulated by Cu²⁺, Zn²⁺, CTAB and Triton X-100 in interstitial, overlying and surface waters. This similarity of responding patterns to the stressors indicated an analogy between dissolved alkaline phosphatase in water column and that in interstitial water, supporting the hypothesis that the polluted sediments act as source of dissolved alkaline phosphatase in eutrophic lakes.     

桑沟湾贝类养殖水域沉积物再悬浮的动力机制及其对水体中营养盐的影响

基于海流、波浪、水环境和沉积环境指标的实测资料,探讨了桑沟湾贝类养殖水域沉积物再悬浮的动力机制,并估算了一次大的动力过程作用下桑沟湾沉积物中氮、磷营养盐的释放量。结果表明,(1)在小风速(≤5.0m/s)条件下,波浪在海水-沉积物界面产生的切应力量值与底流切应力大致相当;在较大风速(5.0～11.8m/s)条件下,波浪切应力比底流切应力高出一个量级;(2)当风浪较小(风速≤3.6m/s)时,随底层流速的周期性变化,底层水体浊度变化并未呈现出明显的规律性,二者相关系数值仅为0.22,这说明底流作用只会引起沉积物的水平输运,对沉积物再悬浮的贡献相对较小,沉积物再悬浮的动力主要来自波浪扰动;(3)据估计,桑沟湾贝类养殖水域沉积物再悬浮的临界波浪切应力在0.04N/m2左右,对应的风速约为8m/s;(4)据估算,一次大的动力过程作用下桑沟湾沉积物中无机氮和活性磷酸盐的最大释放量,春季分别为10.24t和1.71t,这相当于全湾水体中无机氮平均含量增加9.54μg/L,活性磷酸盐平均含量增加1.59μg/L;夏季分别为11.04t和0.95t,相当于全湾水体中无机氮平均含量增加10.28μg/L,活性磷酸盐平均含量增加0.88μg/L;(5)贝类养殖使桑沟湾生物沉积作用加强,而沉积物再悬浮造成的内源释放,又对桑沟湾的水产养殖产生反馈作用。     

太湖沉积物再悬浮对水体中磷形态和浓度时空差异性影响

太湖作为重要的饮用水水源地,因风浪导致其沉积物中磷释放而对水质产生了显著的影响。采用Y型再悬浮发生装置模拟金墅水源地沉积物的再悬浮和沉降过程的结果表明：在5.1 m·s-1的风速作用下,上覆水体中总磷（TP）和磷酸盐（PO3-4-P）浓度存在明显的空间异质性,TP与悬浮物浓度呈正相关;水体TP距离沉积物-水界面越近其浓度越高,而PO3-4-P浓度在垂向分布上差异不显著;与3.2 m·s-1的风速作用相比,8.7 m·s-1的风速能引起更高的TP释放量。这为科学制订抑制沉积物磷释放措施提供了理论依据。     

围网养殖对水生植被和沉积物再悬浮的影响

探讨了围网养殖对水生植被和沉积物再悬浮的影响,结果表明,养殖破坏水生植物资源,使生物量由532 g·m-2下降至45 g·m-2,围栏内的优势种被迫食种代替;沉积物再悬浮显著增强,试验期间,沉积物TP释放增加了336 mg·m-2.保持300 g·m-2的最低生物量对维持湖泊生态系统良性循环、降低再悬浮有重要意义.     

鲟亲鱼培育池塘中浮游生物的组成与变化特点的研究

研究了2009年5-9月鲟亲鱼养殖池塘中浮游生物的种类组成,细胞数量、优势种组成和随季节的变化。结果显示：鲟亲鱼的活动导致养殖池塘沉积物再悬浮,水体透明度较低。浮游植物的种类组成以绿藻门（Chlorophyta）的月牙藻（Selenastrum spp．）和小球藻（Chlorella spp．）等小型个体为主,浮游植物...