太湖新银鱼种群摄食对小江浮游动物群落结构的影响

为探究三峡水库典型支流小江太湖新银鱼（Neosalanx taihuensis）种群摄食对浮游动物群落结构的影响,于2019年1~12月逐月对太湖新银鱼与浮游动物样品进行采集并分析太湖新银鱼胃含物组成与浮游动物群落结构特征。分析结果表明：（1）太湖新银鱼的饵料生物主要为桡足类（相对重要指数百分比（IRI%）=79.97%）,其次为枝角类（IRI%=18.86%）,轮虫占比较少（IRI%=0.001%）。（2）3至6月（太湖新银鱼春群繁殖期）太湖新银鱼生物量迅速上升,并在5、6月维持较高水平的生物量,而浮游动物群落结构呈现小型化趋势,生物量由28.93 mg/L下降至1.13 mg/L;密度由21173.39 ind./L增加至26808.23 ind./L。7月小江禁捕结束,太湖新银鱼生物量开始急剧下降,小江浮游动物中桡足类和枝角类的密度与生物量迅速升高,于8月（密度为151.98 ind./L;生物量为3.39 mg/L）达到全年最高。（3）在太湖新银鱼生物量较高的时期,由于太湖新银鱼对于枝角类和桡足类具有较强的选择性,导致水体中枝角类和桡足类生物量占比（17%~58%）显著低于其它时期（P<0.05）。由此认为,太湖新银鱼生物量与浮游动物群落结构变化存在较强的关联性,太湖新银鱼种群摄食的下行效应可能是小江浮游动物生物量下降及群落结构小型化的关键原因。明晰太湖新银鱼种群生长与浮游动物群落结构的动态变化关系可为小江水华暴发的控制与水生态健康管理提供理论依据。     

广东连江梯级电站开发后春季河流浮游生物群落结构特征

为了更好地了解梯级电站开发后广东连江水质状况,于2008年4月调查了浮游植物和动物的群落结构特征。结果表明,监测到浮游植物28种,其中蓝藻门6种（属）,绿藻门7种（属）,硅藻门12种（属）,甲藻门2种（属）和裸藻门1种。浮游植物丰度在0.35×10^4~1.42×10^4cells/L。浮游植物主要是由硅藻组成,占73.33%~90.62%。Shannon-Weaver多样性指数在2.85~3.47;均匀度指数在1.15~1.25。监测到浮游动物6种,其中桡足类有1种为桡足类幼体（Copepodites）,轮虫类有4种,分别是螺形龟甲轮虫（Keratella cochlearis Gosse）、热带龟甲轮虫（Keratella tropica）、蛭态轮虫（Bdelloidea）、萼花臂尾轮虫（Brachionus calyciflorus）和枝角类1种为长额象鼻氵蚤（Bosminalongirostris）。浮游植物和浮游动物的种类和丰度在下游明显增加。     

渤海中南部海域浮游动物群落结构及其与环境因子的关系

为探究渤海中南部海域浮游动物群落结构及其与环境因子的关系,于2018年5月和9月对渤海中南部海域进行了2个航次的浮游动物调查,并应用冗余分析(RDA)研究环境因子对浮游动物群落结构的影响。结果显示,共鉴定浮游动物39种,隶属8类。5月鉴定浮游动物22种,第一优势种为中华哲水蚤(Clalnus sinicus),9月鉴定29种,第一优势种为强壮箭虫(Sagitta crassa)。调查海域Shannon-Wiener多样性指数均值为2.01,均匀度指数均值为0.61,物种丰富度指数均值为1.05。5月调查海域浮游动物丰度均值(2371.8ind/m_³)高于9月(231.2 ind/m_³)。空间分布上,从5月到9月,浮游动物丰度高值呈现从中部向南部移动的特点。冗余分析结果表明,水温、溶解氧、叶绿素a、盐度和化学需氧量是影响该海域浮游动物群落结构的最主要因子。     

海浪河冬季浮游动物数量特征与群落结构分析

2010年2月份对海浪河10个采样点的浮游动物群落结构进行分析,并利用多维尺度分析（MDS）对各采样点浮游动物群落组成的相似性进行了研究。结果表明：海浪河10个采样点共鉴定出浮游动物4门15属16种,其中原生动物种类最多,7属8种,占50%;轮虫6属6种,占37.5%;桡足类2属2种,占12.5%;没有发现枝角类;浮游动物冬季平均丰度和生物量分别为4.9×104ind./L和0.1293mg/L;经MDS分析后,将10个采样点分为两组,其组内相异性较小,组外相异性较大。     

Relationship between zooplankton abundance and the early marine life history of juvenile chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis> in eastern Hokkaido,Japan

Interannual variations in abundance, timing of outmigration from rivers, growth rate and condition of juvenile chum salmon (Oncorhynchus keta) were studied in the Nemuro Strait (eastern Hokkaido, Japan) during 1999–2002 to establish a possible relationship to zooplankton abundance. The otolith microstructure of juveniles was examined each year in late June to determine their time and size at sea entry (i.e., outmigration), and to estimate the early marine growth rates. Salmon outmigration peaked in mid- or late May, which coincided, in three of the four study years, with the peak release of juveniles into rivers within the study area. Abundance, growth rate and condition of fish were higher in 2001, when—compared to other years—smaller fish experienced higher growth rates, coinciding with greater zooplankton abundance for that year. Our results suggest that high zooplankton abundance positively influenced juvenile chum salmon growth and the condition of the fish during their early marine life despite their small size at sea entry.     

Plankton indices explain interannual variability in Prince William Sound herring first year growth

This study examines the relationships between first year growth of juvenile Prince William Sound herring, temperature and their food. We present time series of herring first year growth, determined from scale measurements as a proxy for herring length, water temperature and indices of multiple trophic levels of plankton obtained from Continuous Plankton Recorder (CPR) sampling on the adjacent Gulf of Alaska shelf. We show that there was a significant correlation between herring growth and water temperature, when the three warmest years were excluded (the mean July and August temperatures were greater than 12.5°C in 1989, 2004 and 2005). There were also strong, significant relationships between the abundance of appropriately sized (for first‐feeding herring) planktonic prey groups and herring growth. First year herring growth was greater in years with higher abundances of diatoms, microzooplankton and small mesozooplankton but not related to variability in abundance of larger mesozooplankton (such as euphausiids and large copepods). Furthermore, the strong interannual relationship between diatoms and herring growth held true even in the warmest years where the relationship between temperature and growth broke down. We also found seasonal timing and abundance changes in the plankton in warm years that would make the prey more abundant during the summer months immediately after metamorphosis of the herring larvae. We thus conclude that young‐of‐the‐year herring may grow better in warm years because the timing of key prey is a better match for their first feeding.     

南昌市3个城中湖泊夏季轮虫和甲壳类群落特征及水质评价

为探究城市湖泊浮游动物群落结构特征和分布与水环境因子之间的关系,并评价南昌市典型城市湖泊夏季水质状况,运用多维尺度分析（MDS）和典范对应分析（CCA）方法,对南昌3个城市湖泊———东湖、青山湖、月亮湖的轮虫和甲壳类浮游动物群落进行了研究,分析了浮游动物的多样性指数。结果表明,轮虫是夏季城市湖泊中浮游动物的优势类群,优势度（Y）大于0．02的浮游动物分别为剪形臂尾轮虫（Brachionus forficula）、裂足臂尾轮虫（Brachionus diversicornis）、萼花臂尾轮虫（Brachionus calyciflorus）、桡足类无节幼体（Copepoda nauplii）和卜氏晶囊轮虫（Asplanchna brightwelli）;3个湖泊之间浮游动物的群落结构差异显著（P ＜0．05）,明显划分为东湖群落、青山湖群落和月亮湖群落。叶绿素 a 浓度、浊度和溶氧是浮游动物分布的显著影响因子（P ＜0．05）。多样性指数评价显示,东湖为清洁型水体,青山湖为清洁－中污型水体,月亮湖为轻污－中污型水体。综合评价表明,东湖和青山湖水体为寡营养水平,月亮湖为中富营养水平。     

以浮游动物初步评价苏州镬底潭的水质污染

镬底潭是苏州市郊的中型湖泊。1987年笔者对镬底潭的浮游动物进行了调查,并就浮游动物评价镬底潭水质污染作初步探讨。经分析,浮游动物高峰期出现的优势种多为耐污性种类,其数量分布呈现上游低下游高的趋势,恰与沿岸工厂废水排放所引起的水质污染浓度成反比,可以推断上游众多工厂的污水排放抑制了浮游动物的生长发育。以浮游动物多样性指数评价该水域的污染程度为中污染;从指示生物组成来看,趋于多污染类型。因此镬底潭水质应属于中污性和多污性的过渡类型。     

有机稻田与常规稻田浮游动物群落比较

采用田间调查、室内鉴定及生态学分析方法研究了有机稻田和常规稻田浮游动物的组成、丰富度及多样性。结果在有机稻田检测到溞属(Daphnia)、裸腹溞属(Moina)、剑水蚤属(Cyclops)和小剑水蚤属(Microcyclops)浮游动物,而在常规稻田仅检测到3属浮游动物;浮游动物的丰度与多样性指数均表现为有机稻田>田头水沟>常规稻田。表明有机栽培可显著增加稻田生态系统浮游动物的多样性。     

海浪河冬季浮游动物数量特征与群落结构分析

2010年2月份对海浪河10个采样点的浮游动物群落结构进行分析,并利用多维尺度分析(MDS)对各采样点浮游动物群落组成的相似性进行了研究.结果表明:海浪河10个采样点共鉴定出浮游动物4门15属16种,其中原生动物种类最多,7属8种,占50%;轮虫6属6种,占37.5%;桡足类2属2种,占12.5%;没有发现枝角类;浮游...